Source: SOUTH CAROLINA STATE UNIVERSITY submitted to NRP
OZONE TREATMENT AS AN ALTERNATIVE FOR CONVENTIONAL FUMIGATION TO MANAGE STORED PRODUCTS INSECTS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
EVANS-ALLEN
Reporting Frequency
Annual
Accession No.
1006443
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
May 16, 2015
Project End Date
May 15, 2019
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
SOUTH CAROLINA STATE UNIVERSITY
(N/A)
ORANGEBURG,SC 29117
Performing Department
Engineering Technologies
Non Technical Summary
Stored product insects cause millions of dollars of loss annually to stored durable commodities such as grain, grain-based products, legumes, dried fruits and nuts and spices. The cigarette beetle, Lasioderma serricorne, the drugstore beetle, Stegobium paniceum and merchant grain beetle Oryzaephilus mercator are serious stored products beetles, cosmopolitan in distribution and pervasive and common pests found in South Carolina and the Southeastern United States. Methyl bromide, a space fumigant widely used to control these insects since 1930s, is been completely phased out in the United States due to its adverse environmental effects. Phosphine fumigation is a long-established effective method to control stored-product insects, but its continuous and indiscriminate use has resulted in the evolution of resistant populations and control failures. Therefore, food and feed industries are constantly looking for effective pest management alternatives, especially those are environmentally benign. Ozone application is currently attracting the attention of scientists, because of its inherent advantages in controlling insects and moulds associated with grain. Ozone is a toxic gas, can kill insects effectively, meantime degrade rapidly to molecular oxygen in atmospheric conditions. Therefore, ozone can be safely and effectively used in food processing industries to disinfest insect infestations. However, there aren't much data available assessing the level of ozone susceptibility to populations of above mentioned insect species and their strains obtained from various geographical locations in the US. In this research, I propose to evaluate the susceptibility of various life stages of above selected species to various doses and exposure time of ozone to effectively establish a dose-time-mortality relationship and to compare that model to strains of adult beetles collected from various states in the US. This proposal is designed to provide cutting-edge training to South Carolina State University students, in addition to train a Research Associate for academic career and to educate farmers, industry representatives and pest control operators in stored products industry. The work also seeks to disseminate information via scientific publications, extension bulletins and internet sources. South Carolina State University (SCSU) is a public university, located in an area that has a traditional, rural, agricultural economy. Being located in an agricultural economy and fulfilling its land grant mission, success in 1890 agricultural research programs is crucial for SCSU. The proposed project will complement the achievement of the institutional land grant mission by training students emphasized in food safety and security, thus, SCSU can produce highly skilled, competent, and socially aware graduates to enable them to work and live productively in a dynamic, global society.
Animal Health Component
(N/A)
Research Effort Categories
Basic
100%
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
72131101130100%
Knowledge Area
721 - Insects and Other Pests Affecting Humans;

Subject Of Investigation
3110 - Insects;

Field Of Science
1130 - Entomology and acarology;
Goals / Objectives
Main goal in general, for this proposed work is to assess the susceptibility and biological responses of selected external feeders of grain to ozone gas. Specifically this project aims to test the following. To establish optimal lethal ozone concentration for different life stages of selected laboratory-reared species, in order to establish a dose-time-mortality response relationship.To identify optimal lethal exposure time for established lethal concentration for all life stages of selected species.To evaluate susceptibility of field collected strains to ozone. To determine biological and reproductive responses of adult insects surviving sub-lethal dosage of ozone gas.
Project Methods
Three devastating insect pests of grain were selected for the study. Lasioderma serricorne (F.) (Coleptera: Anobiidae), Stegobium paniceum (L.) (Coleptera: Anobiidae), and Oryzaephilus mercator Fauvel (Colepotera: Silvanidae) reared in the stored product entomology laboratory at SCSU will be utilized for the study. Adult beetles of 4 to 6-d-old for each species will be introduced to bleached wheat flour in separate 940-ml glass Mason jars and will be maintained at 28oC and 60% relative humidity (r.h.) in an environmental growth chamber. Eggs will be collected after 2 d from the adult colony and will be reared on a medium of 5% dried ground brewer's yeast and 95% bleached wheat flour at 28oC, 60% r.h. and 16:8 (L:D) h photoperiod. Eggs, larvae, pupae and newly emerged adults will be collected from each of these colonies to conduct experiments.Ozone generator: An Ozone Injection System (10 GPM) coupled with Light Weight Bench Top Ozone Analyzer (Ozone Solutions, Hull, IA, USA) will be used to generate various doses of ozone gas for treatment. The Ozone Injection System will generate 10 g per minute pure O3 gas under maximum of 50 PSI pressure that can be delivered to a sealed chamber for treating insects. The injection system will be connected to an inlet and outlet pressure gauge.Establishing optimal lethal ozone concentration:Eggs, larvae, pupae and adults of L. serricorne, S. paniceum and O. mercator will be tested for various concentrations of ozone for fixed exposure time. Initial ozone concentrations to be to be evaluated is 1500 PPM, eventually the concentration will be increased by 300 PPM to evaluate three more incremental concentrations from 1800 to 2400 PPM. Each life stages for each species will be tested for a total of four concentrations for 1 h exposure time to find out the optimal lethal dose and most tolerant insect stage. Establishing optimal exposure time:Once optimal lethal dose is selected based on above experiment, various exposure intervals will be evaluated to determine optimal exposure interval. A time period of 1, 2, 3, and 4h will be exposed to the selected lethal dose. The underline factor is to determine the optimal lethal dose with minimum exposure time for each life stages of three selected species.Analysis of dose-time-mortality responses:The experiment is a Randomized Complete Block Design (RCBD) with repeated measures or replication over time (Block based on time). It is a design with three species and four life stages per species, to be treated where each life stage will be subjected to six replications (six different times). At a given time for a give life stage, 100 life stages will be treated as 20 stages per five pseudo replication. The control experiment is not to expose insect life stages to ozone gas, but to apply every other condition given to experimental treatment unit. If mortality prevails in control units, then treatment mortality will be corrected based on Abbott's formula.Generated mortality data will be subjected to Probit analysis. Time-dose-mortality data for each life stage for each species will be fit to the complementary log-log (CLL) regression model (Robertson and Preisler, 1992), to estimate the time required to kill 50% (LT50) and 99% (LT99) of the exposed insects (SAS Institute, 1998). In the CLL model, percentage mortality (y) is transformed to loge (-loge [1-y/100]) scale, and exposure time (x) is transformed to log10 scale. The goodness-of-fit of the CLL model to the data will be compared using chi-square statistic (SAS Institute, 1998; Robertson and Preisler, 1992).Evaluating the susceptibility of insect strains collected from US geographical locations:Adult insects of L. serricorne, S. paniceum and O. Mercator will be collected from Kansas, Oklahoma, Indiana, Arkansas, and Minnesota and will be tested for variation in susceptibility to established dose-time-mortality response. TheLT99 values of any two geographical locations at given ozone dose will be compared using lethal time ratios, as described by Robertson and Preisler (1992). Lethal time ratios make no assumptions about the parallelism of the responses being compared. At each dose, pair wise comparisons among adults collected from various locations will be tested. The LT99 values are not significantly different from one another (P>0.05) if the 95% confidence limit (CL) for the ratio includes one (Robertson and Preisler, 1992).Evaluating biological and reproductive effects on insects surviving sub-lethal dosage of ozone gas:Exposure to sub-lethal concentrations of ozone may adversely affect biology of insects and may effective in producing either partial or complete sterility in insects. In order to test this hypothesis, newly emerged adults of L. serricorne will be exposed to sub-lethal dosage of ozone and surviving adults will be reared at 28oC, 60% r.h. and 16:8 (L:D) h photoperiod. Then reproductive effects and F1 generation will be assessed against control insects (not exposed to ozone). Reproductive effects will be assessed based on oviposition, egg-to-adult survival rate and development of F1 generation. Data on the number of eggs laid and adult F1progeny production will be transformed to log (x+1) scale, whereas percentage egg-to-adult survival data will be transformed to arcsine (x) 0.5. Data will be subjected to analysis of variance (ANOVA) by using the MIXED procedure of SAS (SAS Institute, 1998) to determine significant differences between the stages and treatments in fecundity, egg-to-adult survival, and progeny production.

Progress 05/16/15 to 05/15/19

Outputs
Target Audience:The project has served the South Carolina State University community by providing employment, mentorship, and training opportunities to several students from different backgrounds. Undergraduate students have gained valuable research experience through this project. The project trained postdoctoral research associate for academic career. Other scientists and professional within the food and pest control industries have also been reached through presentations at conferences. Information shared during conferences reached to industry representatives, farmers and mill owners. PI has provided necessary information via phone calls, emails and personal communication when pest management operatives and pest control companies contacted for information. Target audience: Undergraduate students Stored product entomologists Early career professionals Farmers Pest management operatives Mill managers Extension agents Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?This project has provided job opportunities for a number of people including a Research Associate and many Research Assistants. Eleven undergraduate students and a Postdoctoral Research Associate were employed throughout the project period. Undergraduate students have been employed under the 1890 Research Program as part of this project. Many other students have volunteered to gain some research experience, mentorship, and training to equip them in their future endeavors. Other students have been part of the project through programs such as IDeA Networks of Biomedical Research Excellence, INBRE, and Louis Stokes-South Carolina Alliance for Minority Participation, LS-SCAMP. Training activities have included one-on-one mentorship provided by the Principal Investigator to the Research Associate and Research Assistants, and mentorship provided by the Research Associate to Research Assistants. In terms of professional development activities, the project has given all participants several opportunities to attend and participate in conferences locally, regionally, nationally, and internationally. The project has also provided opportunities for employees working on the project to develop and or improve on their networking, communication, and public-speaking skills through attending and giving presentations at professional meetings. How have the results been disseminated to communities of interest?Results from the project have been disseminated mainly through scientific communications, meetings and publications. Oral and poster presentations have been given at different scientific meetings and universities locally, nationally and internationally. These presentations have helped promote collaborative research with other scientists. Presentations in universities have also helped promote interests in Entomology in students. Presentations have been given to funding agencies too. Local presentations were presented at meetings including the South Carolina Entomological Society of Entomology meeting in Columbia, SC (2015), McCormick, SC (2016) and Georgetown, SC (2017). National presentations include presentations at the Georgia and South Carolina Entomological Societies of Entomology meeting at Helen, GA (2018), Association of 1890 Research Directors and USDA-Agricultural Research Service Joint Food Safety Symposium, Beltsville, MD (2018), the Association of Research Directors Symposium, Atlanta, GA, (2017) and Jacksonville, FL, (2019), the Entomological Society of America national and branch meetings, in Minneapolis, MN (2015), Raleigh, NC (2016), Denver, CO (2017), Memphis, TN (2017), Orlando, FL (2018) and the Annual Professional Agricultural Workers Conference at Tuskegee, AL (2017, 2016), and the Minority in Agriculture and Natural Resources Annual Conference, Jacksonville, FL (2016). International presentations include the Annual Meeting of the Entomological Society of America, Vancouver, Canada (2018), International Working Conference on Stored Product Protection. Berlin, Germany (2018), International Organization for Biological Control, Working Group on Integrated Protection of Stored Products in Slovenia (2017), International Conference on Controlled Atmosphere and Fumigation in Stored Products, New Delhi, India (2016) and International Congress of Entomology, Orlando, FL (2016). Presentations at universities include many presentations at South Carolina State University, SC, and presentations at Winthrop University, SC (2017), Clemson University (2017), University of Lisbon, Portugal (2017), and Kansas State University (2018). Some of the results have been published in peer-reviewed journals such as the Journal of Economic Entomology the Journal of Stored Product Research, and the Journal of the South Carolina Academy of Science, and in the proceedings of the conference of the International Organization for Biological Control and International Working Group on Integrated Protection of Stored Products. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? The effect of ozone on the merchant grain beetle, MGB, and the cigarette beetle, CB, and the rice weevil, RW, was studied during the project period. Insects were exposed to different ozone concentrations in a custom-built bench-top model of ozone generating equipment for different exposure times. All insect stages: eggs, larvae, pupae, and adults of all insects were tested. External feeders: All stages of the MGB and CB were exposed to ozone concentrations of 100-400 ppm at 50 ppm increments for one hour. Adults of the MGB and CB were also exposed to 100, 200, 300, and 400 ppm for one, two, three, four, five or six hours. For the rice weevil, insects were exposed to 200 ppm for 6,12,18,24, 30, 36, 48, and 60 h. Data collected Egg eclosion, adult emergence from larvae and pupae and adult survival were evaluated for each of the stages exposed to Ozone, at various intervals. All data were recorded in Microsoft Excel spread sheet files as and when available and were used for statistical analysis upon completion of all experiments. The following analyses were done for each species of insects. The concentration-mortality data for each life stage were fit to complementary log-log (CLL) regression model to estimate the lethal concentration (LC) required to kill 50%, (LC50) and 99% (LC99) of insects exposed to ozone. Similarly, the time-mortality data for the adults exposed to 100 ppm for different times were also fit to the regression model to estimate the time required to kill 50% (LT50) and 99% (LT99) of insects exposed to each ozone concentration. Summary Statistics and discussion of results The LC50 and LC99 values indicated that higher ozone concentrations are required when insects are exposed to ozone with food compared to when the insects are treated without food. In MGB, when food was provided, adults were the most tolerant and when food was not provided, eggs were the most tolerant. Larvae were the least tolerant regardless of the presence or absence of food. Similarly, longer exposure times are required to kill insects when they are treated with food. There was delayed toxicity effect of ozone on the MGB as significantly fewer insects survived on subsequent days than immediately after treatment. In CB, the concentration-mortality estimates suggested that, generally, higher ozone concentrations were required to kill 99% of insects when treated without food compared to when treated with food. When insects were treated without food, adults were the most tolerant, with eggs being the least tolerant. When treated with food, eggs were the most tolerant and pupae were the least tolerant. When adult insects were exposed to ozone for 1-6 h, there was a lower survival rate in subsequent days after treatment, and this was more pronounced in insects treated without food. This is an indication that the food may be absorbing some of the ozone and need to be saturated before the ozone is available to have an effect on the insects. Statistical analyses on data obtained in the CB experiments indicated that higher ozone concentration with longer duration of exposure may be effective in controlling the insects. Also, different life stages are affected differently by ozone. We also determined the relationships between survival rate and the exposure time for adult CBs exposed to 100 ppm for 1-6 h using TableCurve 2D software. There was a strong relationship 0 DAT between survival rate and exposure time when insects were exposed to ozone in the presence of food. When insects were exposed to ozone in the absence of food, a very weak relationship was observed between survival rate and exposure time immediately after ozone exposure, however, this relationship became rather stronger in subsequent days. Internal feeders: Eggs, immature stages within wheat kernels (referred also to as infested kernels), and adults of the rice weevil were exposed to 200 ppm ozone for 6, 12, 18, 24, 30, 36, 48, and 60 h. Life stages were placed within wheat mass in each of six PVC pipes (10 cm diameter, 30 cm high) at depths of 5 cm, 15 cm, and 25 cm. Three PVC pipes were placed in the ozone generator for the stipulated time and the remaining three PVC pipes were maintained at room conditions for the same duration the ozone exposure was for. Each experiment was repeated three times. All control set-ups were kept in an incubator set at 28 ± 2 0C and 65 ± 2 % as the ozone-treated set-ups were exposed to ozone. Experiments corresponding to each of the exposure period at 200 ppm were repeated for a total of six times. We determined the effect of ozone on treated wheat for germination quality. Germination tests were done in wheat exposed to ozone for 12, 24, 36, 48, and 60 h. Germination tests were performed using wheat at the various depths. Wheat samples were collected from the 5, 15, and 25 cm depths for both treated and untreated wheat. Data collected Survival of eggs were recorded as the percentage egg eclosion at 4, 7, and 10 DAT. Survival of immature stages was recorded as the percentage of adults that emerged from immature stages. For eggs, immature stages, and adults, the rate of survival in treated and control experiments at each depth was determined. Summary Statistics and discussion of results Final percent survival data, i.e. 10, 28, and 2 DAT for eggs, immature stages, and adults, respectively, were subjected to arcsine transformation to normalize the distribution and then analyzed using PROC TTEST. For all life stages, the effect of ozone on survival at various depths within an exposure time was compared. We also compared the effect of ozone at each depth for the various exposure times. Where applicable, mortality in ozone treatments was corrected using Abbott's formula. Then data were arcsine-transformed and subjected to two-way ANOVA. Ozone has been reported to have delayed mortality effect on insects due to a cascade of adverse physiological processes. So we determined, if any, the difference in the survival rate of the insect stages, days following ozone exposure by comparing survival of adults 0, 1, and 2 DAT. Germination of wheat kernels after ozone exposure For the 12, 24, 36, 48, and 60 h exposure times, the correlation between exposure time and percent adult survival and also between exposure time and percent germination of treated wheat were determined. The number of seeds that had germinated after 10 days was recorded. Data were fitted to the equation: y = a + bx, where 'y' is the percent adult survival or percent germination rate and 'x' is the ozone exposure time. Statistical analyses done on the rice weevil data obtained indicated a significant difference in the ozone effect on insect stages between any two depths. Complete mortality has been recorded in adults at the 5 cm depth by day 2 post treatment when the experiment was run for 12 h or longer. Significant adult mortality has also been recorded at 15 cm depths when insects were exposed for 24 h. At 36 h exposure, complete adult mortality was recorded at the 5 cm depth immediately after ozone exposure. Mortality at 15 cm depth was about 60% and at the 25 cm depth, about 5%. Also fewer adults emerged from the infested kernels at the 5 cm depth compared to the other depths. By 28 DAT, less than 1% adults emerged from kernels at 5 cm depth when insects were exposed to ozone for 36 h. Fewer eggs at the 5 cm depth hatched compared to eggs at the 15 cm or 25 cm depth. This is an indication of the need for longer exposure duration and/or higher ozone concentration for insects at deeper depths in order to be affected. Lower germination percentage was recorded at the 5 cm depth compared to the other depths and also to the corresponding control for exposure durations of 24 h and greater. Germination at both the 15 cm and 25 cm depth were similar to their corresponding controls.

Publications

  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: 10. Mahroof, R. M., Amoah, B. and Wrighton, J. (2017). Acute and delayed toxicity effects of ozone on the internal and external feeders of stored products. Conference on the IOBC-Working Group on Integrated Protection of Stored Products, Ljubljana, Slovenia, July 3-5, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: 11. Amoah, B. and Mahroof, R. M. (2017). Ozone as a potential fumigant to control various life stages of stored product insects. Association of 1890 Research Directors, Inc. Research Symposium, April 1-4th, 2017, Atlanta, GA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: 12. Kern, K., Amoah, B. and Mahroof, R. M. (2017). Ozone as a potential disinfectant for Oryzaephilus mercator. Association of 1890 Research Directors, Inc. Research Symposium, April 1-4th, 2017, Atlanta, GA.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: 18. Wrighton, J. L., Kern, K. and Mahroof, R. (2016). Ozone disinfestation of three selected species of stored-product insects: Concentration-time mortality evaluation. South Carolina State University Graduate Research Symposium, Orangeburg, SC, April 14th, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: 19. Wrighton, J. L. and Mahroof, R. (2016). Ozone disinfestation of three selected species of stored-product insects: Concentration-time mortality evaluation. Minority in Agriculture and Natural Resources 31st Annual Conference, Jacksonville, FL, March 30th April 2nd, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: 20. Mahroof, R. M. (2016). Comparison of susceptibility of three stored-product insects to gaseous ozone. Annual meeting of the Southeastern Branch of the Entomological Society of America, Raleigh, NC, March 13-16th, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: 21. Wrighton, J. L. and Mahroof, R. (2015). Ozone disinfestation of three selected species of stored-product insects: Concentration-time mortality evaluation. Twelfth Annual Student Competition, Professional Agricultural Workers Conference and Gamma Sigma Delta, Tuskegee, AL, December 6, 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: 22. Mahroof, R. M. (2015). Real world oppurtunities in stored products pest management. Sixty first Annual Meeting of the South Carolina Entomological Society, Sandhill Research Center, SC, October 1-2nd, 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: 23. Wrighton, J. L. and Mahroof, R. (2015). Ozone disinfestation of three selected species of stored-product insect adults: Concentration-time mortality evaluation. Sixty first Annual Meeting of the South Carolina Entomological Society, Sandhill Research Center, SC, October 1-2nd, 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2015 Citation: 24. Wrighton, J. L. and Mahroof, R. (2015). Ozone Fumigation as an alternative to conventional fumigation to manage stored product insects. 1890 Research and Extension Seminar Series, South Carolina State University, July 28th 2015.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: 25. Mazariego, K, Udonsi, E., Amoah, B. and Mahroof, R. M. (2019). Ozone as an Alternative Fumigant for the Control of Oryzaephilus mercator (Coleoptera: Silvanidae). Association of 1890 Research Directors, Inc. Research Symposium, March-April 2019, Jacksonville, FL.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: 26. Udonsi, E., Amoah, B. and Mahroof, R. M. (2018). Time-Concentration-Mortality Relationships for Oryzaephilus mercator Life stages to Ozone Fumigation. Association of 1890 Research Directors and USDA-Agricultural Research Service Joint Food Safety Symposium, April 23-25th, 2018, Beltsville, MD.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: 27. Glover, D. and Mahroof, R. M. (2017). Efficacy of ozone fumigation against Lasioderma serricorne pupae and adults. Fourteenth Annual Professional Agricultural Workers Conference, Tuskegee, AL, December 3-5, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: 28. Glover, D., Hook, D., Amoah, B. and Mahroof, R. M. (2017). Efficacy of ozone fumigation against Lasioderma serricorne (F.) (Coleoptera: Anobiidae). Sixty third Annual Meeting of the South Carolina Entomological Society, Hobcaw Barony, Georgetown, SC, October 5-6th, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: 29. Wrighton, J., Kern, K. and Mahroof, R. M. (2016). Efficacy of Ozone Against Oryzaephilus mercator. Sixty second Annual Meeting of the South Carolina Entomological Society, Hickory Knob State Park, McCormick, SC, October 27-28th, 2016.
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: 1. Mahroof, R., B. Amoah, and J. Wrighton. (2018). Efficacy of ozone against the life stages of Oryzaephilus mercator (Coleoptera: Silvanidae). Journal of Economic Entomology 111: 470481
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: 2. Amoah, B., and R. Mahroof. (2018). Susceptibility of the life stages of cigarette beetle, Lasioderma serricorne (F.) (Coleoptera: Anobiidae) to ozone. Journal of Stored Product Research, 78:1117
  • Type: Journal Articles Status: Published Year Published: 2019 Citation: 3. Mahroof, R. (2019). Chemical alternatives for managing key stored product insects, Journal of the South Carolina Academy of Science 17(1) 1-3.
  • Type: Journal Articles Status: Awaiting Publication Year Published: 2019 Citation: 4. Amoah, B., and R. Mahroof. (2019). Ozone as a potential fumigant for the control of Sitophilus oryzae (L.) (Coleoptera: Curculionidae) and its effect on germination in wheat. Journal of Economic Entomology (in press)
  • Type: Journal Articles Status: Under Review Year Published: 2019 Citation: 5. Amoah, B., and R. Mahroof. (2019). Susceptibility of Sitophilus oryzae in wheat exposed to ozone for different times. Journal of Agricultural and Urban Entomology (in review)
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: 6. Mahroof, R., and B. Amoah. (2018). Toxic effects of ozone on selected stored product insects and germ quality of germinating seeds. pp. 591595. Proceedings of the 12th International Working Conference on Stored Product Protection Berlin, Germany. October 711, 2018
  • Type: Journal Articles Status: Published Year Published: 2018 Citation: 7. Mahroof, R., B. Amoah, and J. Wrighton. (2018). Acute and delayed toxicity effects of ozone on the internal and external feeders of stored products. pp. 147156. Proceedings of the Conference of the International Organization for Biological Control, Working Group on Integrated Protection of Stored Products Ljubljana, Slovenia. July 35, 2017
  • Type: Other Status: Accepted Year Published: 2019 Citation: 1. Mahroof, R. M. (2019). Beyond Kansas State University: A Continuum of Stored Products Entomology Research, Distinguish Alumni Award presentation, Kansas State University, Manhattan, KS.
  • Type: Other Status: Published Year Published: 2018 Citation: 2. Amoah, and Mahroof, R. M. (2018). Effects of ozone on stored product insects on various commodities. Member Symposium: Sharing ideas and food: stored product pest control across interdisciplinary and geographic borders. Joint Annual Meeting of the Entomological Society of America, Entomological Society of Canada and Entomological Society of British Columbia, Vancouver, BC, Canada, November 11-14, 2018.
  • Type: Other Status: Published Year Published: 2017 Citation: 3. Mahroof, R. M. (2017). Integrated Pest Management Strategies in the Protection of Stored Products: Principles and Practices, Clemson University, December 4th, 2017.
  • Type: Other Status: Published Year Published: 2017 Citation: 4. Amoah, B., Wrighton, J., Kern, K. Fernandez, V.D. and Mahroof, R. M. (2017). Ozone as a potential alternative for management of stored product insect pests. Member Symposium: Stored Products Entomology: Innovative approaches for integrated insect pest management, Annual Meeting of the Entomological Society of America, Denver, CO. November 4-9, 2017.
  • Type: Other Status: Published Year Published: 2017 Citation: 5. Mahroof, R. M. (2017). IPM and Pesticide Alternatives for Managing Stored Product Insects: From Farm to Table. Landscape, Environment, Agriculture and Food Research Center, Institute of Agronomy, University of Lisbon, July 7th, 2017, Lisbon, Portugal.
  • Type: Other Status: Published Year Published: 2017 Citation: 6. Mahroof, R. M. (2017). IPM alternatives to manage insects in durable stored commodities. IPM Forum, Association of 1890 Research Directors, Inc. Research Symposium, April 1-4th, 2017, Atlanta, GA.
  • Type: Other Status: Published Year Published: 2016 Citation: 7. Mahroof, R. M. (2016). Ozone treatment as an alternative for conventional fumigation to manage stored product insects, International Conference on Controlled Atmosphere and Fumigation in Stored Products, New Delhi, India, Nov 7-11th, 2016.
  • Type: Other Status: Published Year Published: 2016 Citation: 8. Mahroof, R. M. (2016). Susceptibility of various life stages of stored product insects to high concentration of ozone. Stored-Products Insect Symposium, International Congress of Entomology, Orlando, FL, September 25-30th, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2019 Citation: 1. Udonsi, E., Mazariego, K, Amoah, B. and Mahroof, R. M. (2019). Dose-Response Relationships for Cigarette Beetle, Lasioderma serricorne (F.) (Coleoptera: Anobiidae) to Ozone Fumigation. Association of 1890 Research Directors, Inc. Research Symposium, March-April 2019, Jacksonville, FL.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: 2. Mahroof, R. M. and Amoah, B. (2018). Toxic Effects of Ozone on Selected Stored Product Insects and Germ Quality of Germinating Seeds. 12th International Working Conference on Stored-Product Protection, Berlin, Germany, October 7-11 th, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: 3. Mahroof, R. M. (2018). IPM Practices to Manage Insects Occurring in Stored Food. Association of 1890 Research Directors and USDA-Agricultural Research Service Joint Food Safety Symposium, April 23-25th, 2018, Beltsville, MD.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: 4. Udonsi, E., Amoah, B. and Mahroof, R. (2018). IPM Practices to Manage Insects Occurring in Stored Food. Association of 1890 Research Directors and USDA-Agricultural Research Service Joint Food Safety Symposium, April 23-25 th, 2018, Beltsville, MD.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: 5. Amoah, B. and Mahroof, R. M. (2018). Susceptibility of Sitophilus oryzae to different durations of ozone exposure. Joint Annual Meeting of the South Carolina Entomological Society and Georgia Entomological Society, Helen, GA, April 4-6th, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: 6. Golver, C. and Mahroof, R. M. (2018). Ozone as a Potential Fumigant for the Control of Lasioderma serricorne (F.) Joint Annual Meeting of the South Carolina Entomological Society and Georgia Entomological Society, Helen, GA, April 4-6th, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2018 Citation: 7. Mahroof, R. M. and Amoah, B. (2018). Detrimental effects of ozone on insects occurring in durable stored commodities. Annual meeting of the Southeastern Branch of the Entomological Society of America, Orlando, FL March 3-7th, 2018.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: 8. Hook, D., Glover, D and Mahroof, R. M. (2017). Stored grain insects and ozone: Dose-response evaluations. Fourteenth Annual Professional Agricultural Workers Conference, Tuskegee, AL, December 3-5, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: 13. Mahroof, R. M. (2017). Toxicity of ozone for internal feeders of stored wheat and effect of ozone on seed germination. Annual meeting of the Southeastern Branch of the Entomological Society of America, Memphis, TN March 12-15th, 2017.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: 14. Kern, K., Wrighton, J., Amoaha, B. and Mahroof, R. M. (2016). Ozone disinfestation stored product insects: Concentration-time mortality evaluation. Thirteenth Annual Student Competition, Professional Agricultural Workers Conference and Gamma Sigma Delta, Tuskegee, AL, December 6, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: 15. Amoah, B. and Mahroof, R. M. (2016). Ozone as a potential fumigant to control cigarette beetle and rice weevil. Sixty second Annual Meeting of the South Carolina Entomological Society, Hickory Knob State Park, McCormick, SC, October 27-28th, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: 16. Kern, K. Wrighton, J., Amoah, B. and Mahroof, R. (2016). Ozone fumigation of merchant grain beetle adults. 1890 Research Symposium, South Carolina State University, July 27th, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2016 Citation: 17. Fowler, A. and Mahroof, R. (2016). Ozone disinfestation of three selected species of stored products insects. LS/SCAMP/INBRE Program Symposium, South Carolina State University, July 26th, 2016.
  • Type: Conference Papers and Presentations Status: Published Year Published: 2017 Citation: 9. Amoah, B. and Mahroof, R. M. (2017). Ozone as a potential fumigant to control of Sitophilus oryzae in wheat. Sixty third Annual Meeting of the South Carolina Entomological Society, Hobcaw Barony, Georgetown, SC, October 5-6th, 2017.


Progress 10/01/16 to 09/30/17

Outputs
Target Audience: Stored product entomologists, scientists, graduate students, undergraduate students, pest management operatives, industrial representatives, farmers and grain storage professionals Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Statistical analyses on data obtained in the CB experiments indicated that higher ozone concentration with longer duration of exposure may be effective in controlling the insects. Also, different life stages are affected differently by ozone. The concentration-mortality data for each life stage of the CB were subjected to probit analyses to estimate the concentration required to kill 50% (LC50) and 99% (LC99) of the insects exposed to ozone either in the presence or absence of food. The concentration-mortality estimates suggested that, generally, higher ozone concentrations were required to kill 99% of insects when treated without food compared to when treated with food. When insects were treated without food, adults were the most tolerant, with eggs being the least tolerant. When treated with food, eggs were the most tolerant and pupae were the least tolerant. When adult insects were exposed to ozone for 1-6 h, there was a lower survival rate in subsequent days after treatment, and this was more pronounced in insects treated without food. Statistical analyses done on the rice weevil data obtained so far indicated a significant difference in the ozone effect on insect stages between any two depths. Complete mortality has been recorded in adults at the 5 cm depth by day 2 post treatment when the experiment was run for 18 h. Significant adult mortality has also been recorded at 15 cm depths when insects were exposed for 24 h. At 36 h exposure, complete adult mortality was recorded at the 5 cm depth immediately after ozone exposure. Mortality at 15 cm depth was about 60% and at the 25 cm depth, about 5% mortality was recorded 2 days after treatment. Also fewer adults emerged from the infested kernels at the 5 cm depth compared to the other depths. By 28 DAT, less than 1% adults emerged from kernels at 5 cm depth when insects were exposed to ozone for 36 h. Fewer eggs at the 5 cm depth hatched compared to eggs at the 15 cm or 25 cm depth. This is an indication of the need for longer exposure duration and/or higher ozone concentration for insects at deeper depths in order to be affected. Lower germination percentage was recorded at the 5 cm depth compared to the other depths and also to the corresponding control for exposure durations of 24 h and greater. Germination at both the 15 cm and 25 cm depth were similar to their corresponding controls. This project has provided job opportunities for a number of people including a postdoctoral research associate and undergraduate assistants. Students have been employed to be a part of this project and many other students have volunteered to gain some research experience and training to equip them in their future endeavors. It has also provided opportunities for people working on the project to develop their networking and public- speaking skills through attending professional meetings, contributing to publications and becoming a member of professional societies. How have the results been disseminated to communities of interest?Results from the project has been disseminated mainly through scientific meetings. Oral and poster presentations have been presented at different scientific meetings locally, nationally and internationally. Local presentations were presented at meetings including the South Carolina Entomological Society meeting in Georgetown, SC. National presentations include presentations at the Association of Research Directors Symposium, Atlanta, GA, the Entomological Society of America, Denver, CO, and Southeastern branch meeting of the Entomological Society of America in Memphis, TN, and the Professional Agricultural Workers Conference at Tuskegee, AL. International presentations include presentations at the conference of the International Organization for Biological Control, Working Group on Integrated Protection of Stored Products in Slovenia, and the University of Lisbon, Portugal. Some of our results have been published in the peer-reviewed journal, Journal of Economic Entomology, and in the proceedings of the conference of the International Organization for Biological Control, Working Group on Integrated Protection of Stored Products. Other results are in preparation for submission for publication in the peer-review journal, Journal of Stored Product Research. Invited talks: Mahroof, R. M. (2017). Overcoming challenges and limitations in directing research at an HBCU: Out of the classroom and into the laboratory. Annual Meeting of the Entomological Society of America, Denver, CO, November 5-8, 2017. Mahroof, R. M. (2017). IPM and Pesticide Alternatives for Managing Stored Product Insects: From Farm to Table. Landscape, Environment, Agriculture and Food Research Center, Institute of Agronomy, University of Lisbon, July 7th, 2017, Lisbon, Portugal. Mahroof, R. M. (2017). IPM alternatives to manage insects in durable stored commodities. IPM Forum, Association of 1890 Research Directors, Inc. Research Symposium, April 1-4th, 2017, Atlanta, GA. ORAL PRESENTATIONS: Hook, D., Glover, D and Mahroof, R. M. (2017). Stored grain insects and ozone: Dose-response evaluations. Fourteenth Annual Professional Agricultural Worker's Conference, Tuskegee, AL, December 6, 2017. Amoah, B., Wrighton, J., Kern, K. Fernandez, V.D. and Mahroof, R. M. (2017). Ozone as a potential alternative for conventional fumigants to manage stored product insect pests. Stored products Symposium, Annual Meeting of the Entomological Society of America, Denver, CO, November 4-9, 2017. Amoah, B. and Mahroof, R. M. (2017). Ozone as a potential fumigant to control of Sitophilus oryzae in wheat. Sixty third Annual Meeting of the South Carolina Entomological Society, Hobcaw Barony, Georgetown, SC, October 5-6th, 2017. Mahroof, R. M., Amoah, B. and Wrighton, J. (2017). Acute and delayed toxicity effects of ozone on the internal and external feeders of stored products. Conference on the IOBC-Working Group on Integrated Protection of Stored Products, Ljubljana, Slovenia, July 3-5, 2017. Amoah, B. and Mahroof, R. M. (2017). Ozone as a potential fumigant to control various life stages of stored product insects. Association of 1890 Research Directors, Inc. Research Symposium, April 1-4th, 2017, Atlanta, GA. Kern, K., Amoah, B. and Mahroof, R. M. (2017). Ozone as a potential disinfectant for Oryzaephilus mercator. Association of 1890 Research Directors, Inc. Research Symposium, April 1-4th, 2017, Atlanta, GA. POSTER PRESENTATIONS: Glover, D., Hook, D., Amoah, B. and Mahroof, R. M. (2017). Efficacy of ozone fumigation against Lasioderma serricorne (F.) (Coleoptera: Anobiidae). Sixty third Annual Meeting of the South Carolina Entomological Society, Hobcaw Barony, Georgetown, SC, October 5-6th, 2017. Glover, D and Mahroof, R. M. (2017). Efficacy of ozone fumigation against Lasioderma serricorne (F.) (Coleoptera: Anobiidae). Fourteenth Annual Professional Agricultural Worker's Conference, Tuskegee, AL, December 6, 2017. What do you plan to do during the next reporting period to accomplish the goals?For the next reporting period, statistical analyses will be carried out on experiments exposing the rice weevil to ozone. Findings will be published in peer-reviewed journals. Experiments will also be designed and carried out to evaluate the effect of sub-lethal doses of ozone gas on the biology of the insects. Ozone has been reported to act slowly, therefore, delayed toxicity effects on the different life stages of the insects will be determined. Insects will be exposed to sub-lethal doses of ozone and surviving insects will be observed for any effects such as survival rate, and other reproductive parameters. These parameters will include adult fecundity, egg-to-adult survival rate, and development of the F1 generation. Experiments will also be carried out to determine the effect of ozone on treated food. Preliminary results indicated that wheat in 30 cm high, 10 cm diameter PVC pipes exposed to ozone may have lower germination rates depending on the exposure duration and the depth within the PVC pipe. Further studies will be carried out to validate this observation.

Impacts
What was accomplished under these goals? The effect of ozone on two external grain feeders, the merchant grain beetle, MGB, and the cigarette beetle, CB, and one internal feeder, rice weevil, RW, was studied during the period under review. Insects were exposed to different ozone concentrations in a custom-built bench-top model of ozone generating equipment for different durations. All insect stages: eggs, larvae, pupae, and adults of all insects were tested. For the rice weevil, the larval and pupal stages, referred to as immature stages, were exposed to ozone while they were still within wheat kernels. For this aspect of the project, all stages (eggs, larvae, pupae and adults) of the MGB and CB would be exposed to ozone concentrations of 100-400 ppm at 50 ppm increments for one hour. Adults of the external feeders would be exposed to 100, 200, 300, and 400 ppm for one, two, three, four, five or six hours. For the rice weevil, insects would be exposed to 200 ppm for 6 h and then at 6 -12 h increments until 100% mortality of all stages would be achieved. Below is the description of experiments accomplished for the reporting period: Insects for study Prior to the experiments, the MGB was reared on rolled oats while the CB was reared on a 95% whole wheat flour and 5% yeast diet mix. The rice weevil was reared on whole wheat. New colonies were established by transferring newly emerged adults to rearing jars with diet specific for each species. The adults were removed after 48 h and the rearing jars incubated until the larval, pupal or adult stage of the insect was reached and used for the experiments. For rice weevil, kernels with immature stages developing within them were used. To obtain eggs, newly emerged adults of each species were allowed to lay eggs on a thin layer of white flour for up to 48 h. External feeders' Experiments Egg experiments Cigarette beetle eggs were exposed to ozone concentration of 250-400 ppm. Twenty eggs were transferred into each of 20 Petri dishes. Ten of the Petri dishes were for ozone treatment and ten for control. Five of the treatment dishes each had 2 g corn meal, and the other five were without food. Similarly, five of the 10 control dishes had food and the remaining five were without food. The control dishes were placed in an incubator while the treatment dishes were placed in the ozone generator set at the concentration being tested for 1 h. Eggs were observed for any physical changes immediately after ozone exposure. Eggs were observed again at 1, 2, 4, 7, and 10 days after treatment for eclosion. Larval experiments Cigarette beetle larvae were exposed to 100-400 ppm, and merchant grain beetle larvae were exposed to ozone concentrations of 300-400 ppm at 50 ppm increments. Twenty late instar larvae of MGB or CB were transferred into each of 20 glass petri dishes. Ten of these Petri dishes were for ozone treatment; five of which had food (white flour for MGB and the original CB diet for CB) and the remaining five without food. Similarly, the remaining 10 dishes were the control dishes, five with food and five without food. The 10 treatment dishes were then transferred to the ozone generator set at the concentration being tested for 1 h while the 10 control dishes were placed in the incubator. After the 1 h exposure duration, the larvae were observed for mortality. Mortality was observed again at 1, and 2 days after treatment, after which the contents of each of the 20 Petri dishes were transferred into separate jars with lids and 10 g of the original food specific to each species was added to each of the 20 jars. The addition of food was to prevent starvation since the larvae were observed for adult development up to day 20 post-treatment for MGB and day 28 post-treatment for CB. Pupal experiments Cigarette beetle pupae were exposed to ozone concentrations of 250-400 ppm and merchant grain beetle pupae were exposed to 100-400 ppm at 50 ppm increments. The experimental design for pupal experiments was similar to as described for the eggs. The original diet was used where food was required. Pupae for CB used in experiments still had their pupal casing or cocoon intact, while MGB pupae were without cocoon as they would naturally occur. Experimental jars were checked for adult development beginning day 7 till day 15 post-treatment. Adult experiments Adults of MGBs and CBs were treated with ozone concentrations of 100 ppm and 300 ppm respectively for 2 h. The design for adult experiments was also similar to as described for the egg experiments above except that the original diets for the adults were used where food was required. Adult mortality was checked immediately after treatment and then at 1, and 2 days post-treatment. For each external feeder experiment, each treatment was replicated five times with the exception of MGB egg experiments, which were replicated three times. Each experiment was repeated three times. Eggs, immature stages, and adults of the rice weevil were exposed to 200 ppm ozone for 18, 24, 30, 36, or 48 h. Twenty eggs were placed in a 5 cm high, 2 cm diameter plastic vial that had been perforated to ensure air circulation. Twenty adults and 40 kernels with immature stages were placed in a muslin pouch. A vial and a pouch were placed within wheat mass in each of six PVC pipes (10 cm diameter, 30 cm high) at depths of 5 cm, 15 cm, and 25 cm. Three PVC pipes were placed in the ozone generator for the stipulated time and the remaining three PVC pipes were maintained at room conditions for the same duration the ozone exposure was for. Adult mortality was recorded at 0, 1, and 2 days post-treatment. Egg eclosion was recorded up to day 10 post-treatment and kernels with immature stages were observed for adult emergence up to day 28 post-treatment. Each treatment was replicated three times and repeated six times. Preliminary studies were carried out to determine the effect of ozone on treated wheat during experiments exposing rice weevil in wheat to ozone. Germination tests were performed using wheat at the various depths. Wheat samples were collected from the 5, 15, and 25 cm depths for both treated and untreated wheat. For each treatment, the germination test was performed and the number of seeds that had germinated 10 days after planting was recorded. Data collection and analyses All data are being recorded in Microsoft Excel spread sheet files as and when available and statistical analyses will be done upon completion of all replications for each experiment. The following analyses have been done for the completed experiments. For MGB, the concentration-mortality data for each life stage were fit to complementary log-log (CLL) regression model to estimate the lethal concentration (LC) required to kill 50% (LC50), and 99% (LC99) of insects exposed to ozone. Similarly, the time-mortality data for the adults exposed to 100 ppm for different durations were also fit to the regression model to estimate the time required to kill 50% (LT50), and 99% (LT99) of insects exposed to each ozone concentration. The LC50 and LC99 values indicated that higher ozone concentrations are required when insects are exposed to ozone with food compared to when the insects are treated without food. When food was provided, adults were the most tolerant and when food was not provided, eggs were the most tolerant. Larvae were the least tolerant regardless of the presence or absence of food. Similarly, longer exposure times are required to kill insects when they are treated with food. This is an indication that the food may be absorbing some of the ozone and as a result, need to be saturated before the gas is available to have an effect on the insects.

Publications

  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Mahroof, R., Amoah, B. and J. Wrighton (2017). Efficacy of ozone against the Life stages of Oryzaephilus mercator (Coleoptera: Silvanidae). Journal of Economic Entomology (2017), Pp 112; doi: 10.1093/jee/tox293.
  • Type: Journal Articles Status: Published Year Published: 2017 Citation: Bingham A. C., Bh. Subramanyam, R. Mahroof and S. Alavi (2017). Development and validation of a model for predicting survival of young larvae of Tribolium castaneum exposed to elevated temperatures during heat treatment of grain-processing facilities. Journal of Stored Products Research 72: 143-152.
  • Type: Book Chapters Status: Published Year Published: 2017 Citation: Dessalegn, T., Solomon, T., Gebrekiristos, T., Solomon, A., Seboka,S., Chane, Y., Subramanyam, Bh., Roberts, K. A., Abay, F. and Mahroof, R. (2017). Post-harvest wheat losses in Africa: an Ethiopian case study. In: Langridge, P. (ed.), Achieving sustainable cultivation of wheat Volume 2: Cultivation techniques, Burleigh Dodds Science Publishing, Cambridge, UK (ISBN: 978 1 78676 020 3; www.bdspublishing.com). Pp: 83-104.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Mahroof, R., Amoah, B. and J. Wrighton (2017). Acute and Delayed Toxicity Effects of Ozone on the Internal and External Feeders of Stored Products. Proceedings of the Conference of the International Organization for Biological Control, Working Group on Integrated Protection of Stored Products Ljubljana, Slovenia 3-5 July 2017.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Amoah, B. and Mahroof, R. M. (2017). Ozone as a potential fumigant to control various life stages of stored product insects. Association of 1890 Research Directors, Inc. Research Symposium, April 1-4th, 2017, Atlanta, GA.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Kern, K., Amoah, B. and Mahroof, R. M. (2017). Ozone as a potential disinfectant for Oryzaephilus mercator. Association of 1890 Research Directors, Inc. Research Symposium, April 1-4th, 2017, Atlanta, GA.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Glover, D., Hook, D., Amoah, B. and Mahroof, R. M. (2017). Efficacy of ozone fumigation against Lasioderma serricorne (F.) (Coleoptera: Anobiidae). Sixty third Annual Meeting of the South Carolina Entomological Society, Hobcaw Barony, Georgetown, SC, October 5-6th, 2017.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Glover, D and Mahroof, R. M. (2017). Efficacy of ozone fumigation against Lasioderma serricorne (F.) (Coleoptera: Anobiidae). Fourteenth Annual Professional Agricultural Workers Conference, Tuskegee, AL, December 6, 2017.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Hook, D., Glover, D and Mahroof, R. M. (2017). Stored grain insects and ozone: Dose-response evaluations. Fourteenth Annual Professional Agricultural Workers Conference, Tuskegee, AL, December 6, 2017.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Amoah, B., Wrighton, J., Kern, K. Fernandez, V.D. and Mahroof, R. M. (2017). Ozone as a potential alternative for conventional fumigants to manage stored product insect pests. Stored products Symposium, Annual Meeting of the Entomological Society of America, Denver, CO, November 4-9, 2017.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Amoah, B. and Mahroof, R. M. (2017). Ozone as a potential fumigant to control of Sitophilus oryzae in wheat. Sixty third Annual Meeting of the South Carolina Entomological Society, Hobcaw Barony, Georgetown, SC, October 5-6th, 2017.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2017 Citation: Mahroof, R. M., Amoah, B. and Wrighton, J. (2017). Acute and delayed toxicity effects of ozone on the internal and external feeders of stored products. Conference on the IOBC-Working Group on Integrated Protection of Stored Products, Ljubljana, Slovenia, July 3-5, 2017.
  • Type: Other Status: Accepted Year Published: 2017 Citation: Mahroof, R. M. (2017). Overcoming challenges and limitations in directing research at an HBCU: Out of the classroom and into the laboratory. Annual Meeting of the Entomological Society of America, Denver, CO, November 5-8, 2017.
  • Type: Other Status: Accepted Year Published: 2017 Citation: Mahroof, R. M. (2017). IPM and Pesticide Alternatives for Managing Stored Product Insects: From Farm to Table. Landscape, Environment, Agriculture and Food Research Center, Institute of Agronomy, University of Lisbon, July 7th, 2017, Lisbon, Portugal.
  • Type: Other Status: Accepted Year Published: 2017 Citation: Mahroof, R. M. (2017). IPM alternatives to manage insects in durable stored commodities. IPM Forum, Association of 1890 Research Directors, Inc. Research Symposium, April 1-4th, 2017, Atlanta, GA.


Progress 10/01/15 to 09/30/16

Outputs
Target Audience: Target Audience: Undergraduate students, non-student staff, post-doctoral research associate, other scientists and researchers, stored-product managers, industry professionals, pest control operators for structural and urban pest management. Population groups such as racial and ethnic minorities and those who are socially, economically, or educationally disadvantaged were primary recruiters for this project. Such population groups include women in science, African-American, African Native and Hispanic. PI's efforts: Laboratory instructions and practicum experiences were provided for undergraduate students. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Undergraduate student attended two conferences and a seminar series. Temporary staff and research associate each attended two regional conferences. PI attended two international conferences and two reginal conferences. PI trained one-on one basis all undergraduate students, temporary staff and postdoctoral research associate about laboratory techniques, experimental protocols, data management and reporting throughout the year. Meeting details are given below. Ms. Kern participated and delivered an oral presentation at the 13th Professional Agricultural Workers Conference held in Tuskegee, AL on December 6th, 2016. Ms. Kern presented at the summer 1890 Seminar Series Ms. Wrighton, Ms. Kern, Dr. Amoah and Dr. Mahroof attended Sixty Second Annual Meeting of the South Carolina Entomological Society, held in Hickory Knob State park, McCormick, SC on October 27-28th, 2016. Ms. Wrighton participated at the Minority in Agriculture and Natural Resources 31st Annual Conference, Jacksonville, FL, 03/30-04/02, 2016 and South Carolina State University's Research Forum on April 30th, 2016. Dr. Mahroof attended the South Eastern Branch annual meeting of the Entomological Society of America held in Raleigh, NC in March 13-16th 2016, International Congress of Entomology in Orlando FL during Sep 25-30th, 2016 and the Controlled Atmosphere and Fumigation Workshop held in New Delhi, India during November 7-11th, 2016. How have the results been disseminated to communities of interest?Results have been presented at different scientific meetings locally, nationally and internationally. Details of presentations are given below. Mahroof, R. M. (2016). Ozone treatment as an alternative for conventional fumigation to manage stored product insects, International Conference on Controlled Atmosphere and Fumigation in Stored Products, New Delhi, India, Nov 7-11th, 2016. Amoah, B. and Mahroof, R. M. (2016).Ozone as a potential fumigant to control cigarette beetle and rice weevil.Sixty second Annual Meeting of the South Carolina Entomological Society, Hickory Knob State Park, McCormick, SC, October 27-28th, 2016. Mahroof, R. M. (2016). Susceptibility of various life stages of stored product insects to high concentration of ozone. Stored-Products Insect Symposium, International Congress of Entomology, Orlando, FL, September 25-30th, 2016. Kern, K. Wrighton, J., Amoah, B. and Mahroof, R. (2016).Ozone fumigation of merchant grain beetle adults. 1890 Research Symposium, South Carolina State University, July 27th, 2016. Fowler, A. and Mahroof, R. (2016).Ozone disinfestation of three selected species of stored products insects.LS/SCAMP/INBRE Program Symposium, South Carolina State University, July 26th, 2016. Wrighton, J. L., Kern, K. and Mahroof, R. (2016). Ozone disinfestation of three selected species of stored-product insects: Concentration-time mortality evaluation. South Carolina State University Graduate Research Symposium, Orangeburg, SC, April 14th, 2016. Wrighton, J. L. and Mahroof, R. (2016). Ozone disinfestation of three selected species of stored-product insects: Concentration-time mortality evaluation. Minority in Agriculture and Natural Resources 31st Annual Conference, Jacksonville, FL, March 30th April 2nd, 2016. Mahroof, R. M. (2016). Comparison of susceptibility of three stored-product insects to gaseous ozone. Annual meeting of the Southeastern Branch of the Entomological Society of America, Raleigh, NC, March 13-16th, 2016. What do you plan to do during the next reporting period to accomplish the goals?The remaining experiments will be conducted and analyses will be completed. Apart from the LC (lethal concentration) and LT (lethal time) values, other analyses will be conducted. Lethal effects of Ozone in an organism has been reported to being acting slowly, therefore, delayed toxicity effects on the different life stages of the insects will be determined. The LC and LT ratios will be determined. Briefly, The LC99 values of any two life stages of each species will be compared using lethal concentration ratios. Similarly, the LT99 values of any two concentrations tested in the experiments involving multiple hour exposure periods will also be compared using the lethal time ratios. This will help determine if there are differences among the life stages in their response to a particular ozone concentration (LC ratios) or if there are differences among the concentrations at the different exposure times (LT ratios).

Impacts
What was accomplished under these goals? The effect of ozone on three external grain feeders, merchant grain beetles (MGBs), cigarette beetles (CBs), and drugstore beetles (DSBs), and one internal feeder, rice weevil (RW), was studied during the period under review. Insects were exposed to different ozone concentrations in a bench-top ozone generating equipment for different durations. Insect stages tested were eggs, larvae and adults of MGBs, eggs, pupae, and adults of CBs, and adults of DSBs. For the RW, eggs, immature stages within wheat kernels, and adults were tested. For this aspect of the project, the following concentrations are being tested for the external feeders: Eggs, larvae, pupae and adults: 100 ppm to 400 ppm at 50 ppm increments for one hour. Adults: 100, 200, 300, and 400 ppm. Insects would be exposed to each concentration for one, two, three, four, five or six hours. For the RW, insects were exposed to 200 ppm for six, 12, or 18 hours. For the reporting period, the following experiments have been completed: For MGBs, eggs and adults were exposed to ozone concentrations ranging from 100 - 400 ppm for one hour. Larvae were tested at ozone concentrations 100 - 250 ppm. Adults were also tested at 100 ppm or 200 ppm for 1, 2, 3, 4, 5, or 6 h. For CBs, eggs and pupae were treated with ozone concentration ranging from 100 - 200 ppm, while adults were treated with ozone at 100 - 400 ppm for one hour. Adults were also exposed to 100 ppm or 200 ppm for 1, 2, 3, 4, 5, or 6 h. Drugstore beetles were treated at 100 and 150 ppm for one hour. Prior to the external feeder experiments, the MGBs were reared on rolled oats while the CBs and DSBs were reared on a 95% whole wheat flour (WWF) and 5% yeast diet mix. New colonies were established by transferring newly emerged adults to rearing jars with diet specific for each species. The adults were removed after 48 h and the rearing jars incubated at 28 ± 2 0C and 65 ± 2% until the larval, pupal or adult stage of the insect was reached and used for the experiments. To obtain eggs, newly emerged adults of each species were allowed to lay eggs on a thin layer of white flour for 24 h. For each species tested, twenty eggs were transferred into each of 20 Petri dishes. Ten of the Petri dishes were for ozone treatment and ten for control. Five of the treatment dishes each had food (corn meal for CBs and rolled oats for MGBs), and the other five were without food. Similarly, five of the 10 control dishes had food and the remaining five were without food. The control dishes were placed in an incubator at 28 ± 2 0C and 65 ± 2% RH while the treatment dishes were placed in the ozone generator at the concentration and duration being tested. Eggs were observed for any physical changes immediately after ozone exposure. Eggs were observed again at 24 h, 48 h, day 4, day 7, and day 10 for hatching. Twenty late instar larvae of MGB were transferred into each of 20 glass petri dishes. Ten of these Petri dishes were for ozone treatment; five of which had 5 g white flour each and the remaining five without flour. Similarly, the remaining 10 dishes were the control dishes, five with flour and five without flour. The 10 treatment dishes were then transferred to the ozone generator set at the concentration being tested for 1 h while the 10 control dishes were placed in the incubator at 28 ± 2 0C and 65 ± 2% RH. After 1 h, the larvae were observed for mortality. Mortality was observed again at 24 h and 48 h. After 48 h, the contents of each of the 20 Petri dishes were transferred into separate jars with lids and 10 g of rolled oats added to each of the 20 jars. The addition of rolled oats was to prevent starvation since the larvae were observed till adult emergence at day 16, day 18, and day 20 post-treatment. The design for CB pupal experiments was similar to as described for the eggs. The original diet for CB was used where food was required. Pupae used in experiments still had their pupal casing or cocoon intact. Adult emergence from experimental jars was checked at day 7, day 9, day 11, day 13 and day 15 post-treatment. The design for adult experiments was also similar to as described for the egg experiments except that the original diets for the adults was used where food was required. Adult mortality was checked at 0, 24, and 48 h post-treatment. Eggs, immature stages within wheat kernels, and adults of RW were exposed to 200 ppm ozone for 6 h or 12 h. Twenty eggs were placed in a 5 cm high and 0.5 cm diameter plastic vial which had been perforated several times to ensure gaseous exchange. Twenty adults and 40 kernels with immature stages were placed in a muslin pouch. A tube and a pouch were placed within wheat mass in each of six PVC pipes (10 cm diameter, 30 cm high) at depths of 5 cm, 15 cm, and 25 cm. Three PVC pipes were placed in ozone generator for the duration and the remaining three PVC pipes were maintained at room conditions for the same duration. Adult mortality was recorded at 0 h, 24 h and 48 h post-treatment. Egg hatch was recorded up to day 10 post-treatment and kernels with immature stages were observed for adult emergence up to day 28 post-treatment. All control set-ups were kept in an incubator set at 28 ± 20C and 65 ± 2 % as the ozone-treated set-ups were exposed to ozone. After ozone exposure, all insects were transferred to the incubator for the remaining period of study. For each external feeder experiment, each treatment was replicated five times with the exception of MGB egg experiments, which were replicated three times. Each experiment was repeated three times. For the RW experiments, each treatment was replicated three times and repeated six times. Data collection and analyses: All data are being recorded in Microsoft Excel spread sheet files and will be used for statistical analysis upon completion of all experiments. The following analyses have been done for the completed experiments. For all stages of internal feeders, concentration-mortality data for each life stage of each species were fit to complementary log-log (CLL) regression model to estimate the lethal concentration (LC) required to kill 50%, (LC50) and 99% (LC99) of insects exposed to ozone. Similarly, the time-mortality data for the adults exposed to 100 ppm for different durations were also fit to the regression model to estimate the time required to kill 50% (LT50) and 99% (LT99) of insects exposed to each ozone concentration. The LC50 and LC99 values indicated that higher ozone concentrations are required when insects are exposed to ozone with food compared to when the insects are treated without food. Similarly, longer exposure times are required to kill insects when they are treated with food. This is an indication that the food may be absorbing some of the ozone and need to be saturated before the ozone is available to have an effect on the insects.

Publications

  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: 1. Kern, K., Amoah, B., & Mahroof, R. (2016). Ozone as a Potential Disinfectant for Oryzaephilus Mercator. 74th Annual Professional Agricultural Workers Conference, Tuskegee University, December 4, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: 2. Mahroof, R. M. (2016). Ozone treatment as an alternative for conventional fumigation to manage stored product insects. International Conference on Controlled Atmosphere and Fumigation in Stored Products, New Delhi, India, Nov 7-11th, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: 3. Amoah, B. & Mahroof, R. M. (2016). Ozone as a potential fumigant to control cigarette beetle and rice weevil. Sixty second Annual Meeting of the South Carolina Entomological Society, Hickory Knob State Park, McCormick, SC, October 27-28th, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: 4. Mahroof, R. M. (2016). Susceptibility of various life stages of stored product insects to high concentration of ozone. Stored-Products Insect Symposium, International Congress of Entomology, Orlando, FL, September 25-30th, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: 5. Kern, K. Wrighton, J., Amoah, B. & Mahroof, R. (2016). Ozone fumigation of merchant grain beetle adults. 1890 Research Symposium, South Carolina State University, July 27th, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: 6. Fowler, A. and Mahroof, R. (2016). Ozone disinfestation of three selected species of stored products insects. LS/SCAMP/INBRE Program Symposium, South Carolina State University, July 26th, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: 7. Wrighton, J. L., Kern, K. & Mahroof, R. (2016). Ozone disinfestation of three selected species of stored-product insects: Concentration-time mortality evaluation. South Carolina State University Graduate Research Symposium, Orangeburg, SC, April 14th, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: 8. Wrighton, J. L. & Mahroof, R. (2016). Ozone disinfestation of three selected species of stored-product insects: Concentration-time mortality evaluation. Minority in Agriculture and Natural Resources 31st Annual Conference, Jacksonville, FL, March 30th April 2nd, 2016.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2016 Citation: 9. Mahroof, R. M. (2016). Comparison of susceptibility of three stored-product insects to gaseous ozone. Annual meeting of the Southeastern Branch of the Entomological Society of America, Raleigh, NC, March 13-16th, 2016.


Progress 05/16/15 to 09/30/15

Outputs
Target Audience: Professionals, scientists, stored product entomologists. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? The undergraduate student attended two professional meeting, and the PI attended one conference. Ms. Wrighton won the award for oral presentation at the 12th Professional Agricultural Workers Conference held in Tuskegee, AL on December 6th, 2015. How have the results been disseminated to communities of interest? Conference presentations and proceedings: Mahroof, R. M. (2015). Real world oppurtunities in stored products pest management. Sixty-first Annual Meeting of the South Carolina Entomological Society, Sandhill Research Center, SC, October 1-2, 2015. Wrighton, J. L. and Mahroof, R. (2015). Ozone disinfestation of three selected species of stored-product insect adults: Concentration-time mortality evaluation. Sixty-first Annual Meeting of the South Carolina Entomological Society, Sandhill Research Center, SC, October 1-2, 2015. Wrighton, J. L. and Mahroof, R. (2015). Ozone disinfestation of three selected species of stored-product insects: Concentration-time mortality evaluation. Professional Agricultural Workers Conference and Gamma Sigma Delta 12th Annual Student Competition; Tuskegee University, Alabama, Dec 6, 2015. What do you plan to do during the next reporting period to accomplish the goals? Commissioning for the ozone generator has been completed. A training course will be delivered on Jan 14, 2016 to staff and students on the operating and the handling of the Ozone Generator. All goals set for this year will be accomplished as planned. Work is in progress to hire a postdoctoral researcher to the team.

Impacts
What was accomplished under these goals? Insect master colonies that provide life stages of cigarette beetle, Lasioderma serricorne (F.) (Coleptera: Anobiidae), drug store beetle Stegobium paniceum (L.) (Coleptera: Anobiidae) and merchant grain beetle Oryzaephilus mercator Fauvel (Colepotera: Silvanidae) were established and maintained regular basis. Adults of L. serricorne, S. paniceum and O. mercator were exposed to ozone concentration of 1500, 1800, 2100, and 2400 PPM for one hour. Adult mortality was assessed 0, 24, and 48 h post exposure. Data were analyzed, summarized, and presented in conferences and professional meetings. Three regional meetings were attended by the PI and participating students. Students won the award for oral presentation at the 12th Professional Agricultural Workers Conference held in Tuskegee, AL on December 6th, 2015. Procedures and paperwork were completed in designing, manufacturing, and purchasing an ozone generator.

Publications

  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2015 Citation: Wrighton, J. L. and Mahroof, R. (2015). Ozone disinfestation of three selected species of stored-product insect adults: Concentration-time mortality evaluation. Sixty-first Annual Meeting of the South Carolina Entomological Society, Sandhill Research Center, SC, October 1-2, 2015.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2015 Citation: Wrighton, J. L. and Mahroof, R. (2015). Ozone disinfestation of three selected species of stored-product insects: Concentration-time mortality evaluation. Professional Agricultural Workers Conference and Gamma Sigma Delta 12th Annual Student Competition; Tuskegee University, Alabama, Dec 6, 2015.
  • Type: Conference Papers and Presentations Status: Accepted Year Published: 2015 Citation: Mahroof, R. M. (2015). Real world oppurtunities in stored products pest management. Sixty-first Annual Meeting of the South Carolina Entomological Society, Sandhill Research Center, SC, October 1-2, 2015.