Progress 06/27/19 to 07/31/22
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 Post-Doctoral Research Associate and many Research Assistants. Five 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. Four 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 came through programs such as Biomedical Research Excellence, 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 writing, networking, communication, and public-speaking skills through attending and giving presentations at professional meetings. The PI was able to present project outcomes in invited seminars and presentation in various venues and publish articles in conference proceedings and refereed journals. PI was able to further apply and seek external funding based on the results from the current project. 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 annual meeting (Oct 2021, virtual) and at the SCSU University venue. National presentations include invited seminar at the Department of Entomology, Rutgers, The State University of New Jersey (Nov 2021), invited talk during the Annual Virtual Meeting of the South Eastern Branch of the Entomological Society of America (March 2021) the Annual Meeting of the Entomological Society of America (Nov 2021) the virtual 2020 annual meeting of Entomological Society of America and 14th Fumigants and Pheromones Conference (virtual, November 2020). International presentations include presentations and seminars at University of Peradeniya, Sri Lanka, Rajarata University of Sri Lanka (Jan-March 2020 several seminars), Embrapa Soybean in Brazil, Federal Public Research Center, Ministry of Agriculture, Livestock and Food Supply in Brazil (Dec 2020), invited talk at the Faculty of Agriculture, University of Peradeniya, Sri Lanka (Feb 2021) and at the Controlled Atmosphere and Fumigation in Stored Products Conference in Manitoba, Canada (Aug 2021). Invited talks: 1. Mahroof, R. M. (2021). Stored-Product Pest Management in a Changing World: Challenges and Accomplishments. Invited seminar, Department of Entomology, Rutgers, The State University of New Jersey, November 19th, 2021, Webinar. 2. Mahroof, R. M. (2021). Engaging for a Good Cause: Bugs, an HBCU and a Woman of Color in Entomology. Symposium on Diversity and Inclusion, Annual meeting of the Southeastern Branch of the Entomological Society of America, March 29-31st, 2021, Virtual Meeting. 3. Mahroof, R. M. (2021). World of Insects. Trends in Biology Seminar Series, Department of Agricultural Biology, Faculty of Agriculture, University of Peradeniya, Sri Lanka. February 12th, 2021, Webinar. 4. Mahroof, R. M. (2020). Stored Product Insect Management: From Farm to Folk. Embrapa Soybean in Brazil, Federal Public Research Center, Ministry of Agriculture, Livestock and Food Supply, Brazil, December 15th, 2020, virtual meeting. 5. Mahroof, R. M. (2020). Stored Products Entomology for All: My Fulbright Experiences in Developing Stored Products Research and Teaching in Sri Lanka. Symposium on stored products insect management. Annual Meeting of the Entomological Society of America, November 16-19, 2020, virtual meeting. 6. Mahroof, R. M. (2020). Pheromone research and field applications. Wendell Burkholder Recognition Lecture, 14th Fumigants and Pheromones Conference. May 11-14th, 2020, Victoria Falls, Zimbabwe (Virtual meeting on October 22nd, 2020 due to COVID-19 Pandemic). 7. Mahroof, R. M. (2020). Research in stored products entomology: Achievements, challenges and prospects. Fulbright scholar invited research seminar. Faculty of Agriculture, University of Peradeniya, March 25th, 2020, Peradeniya, Sri Lanka. 8. Mahroof, R. M. (2020). Assessing and Grading Graduate Students: the USA perspective during the workshop on "Assessment Strategies in the Modern World", Faculty of Agriculture, University of Peradeniya, March 13, 2020, Sri Lanka. 9. Mahroof, R. M. (2020). Stored product pest management in Sri Lanka: An update on research, teaching curriculum design and student mentoring. South and Central Asia Fulbright Conference, February 24-26th, 2020, Kochi, India. 10. Mahroof, R. M. (2020). My experiences in stored products entomology: Am I still biting my nails? Fulbright scholar invited research seminar. Faculty of Agriculture, Rajarata University of Sri Lanka, February 14th, 2020, Anradhapura, Sri Lanka. 11. Mahroof, R. M. (2020). Insects and Society. Fulbright Scholar invited teaching seminars. Faculty of Agriculture, Rajarata University of Sri Lanka, February11th, 2020 and Faculty of Applied Sciences, Rajarata University of Sri Lanka, February12th, 2020, Anradhapura, Sri Lanka. Other oral presentations: 1. Mahroof, R. M. (2021). Effects of delayed mating on the mating performance of Lasioderma serricorne (F.). Annual meeting of the Entomological Society of America, Oct 30-Nov 3rd, 2021. 2. Mahroof, R. M. and Paudel S. (2021). Dose-response of selected stored product insects to ozone treated on various surface materials, 11th International Conference on Controlled Atmosphere and Fumigation in Stored Products, Manitoba, WI, Canada (Virtual), Aug 23-27th, 2021. 3. Mahroof, R. M. (2021). Stored Products Research and Teaching in Sri Lanka: My Fulbright Experiences. Annual meeting of the Southeastern Branch of the Entomological Society of America, March 29-31st, 2021, Virtual Meeting. 4. Mahroof, R. M. (2020). Mating disruption and mating delays and subsequent effects on reproductive performance of Lasioderma serricorne (F.). Sixty sixth Annual Meeting of the South Carolina Entomological Society, Virtual Meeting, October 2nd, 2020. 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 one internal feeder and two external grain feeders, first a weevil, S. oryzae, second a beetle, T. castaneum, and third a moth, P. interpunctella, were studied during the project period. Initially, the most-ozone-tolerant life stage for each species was determined by preliminary trials. Eggs, larvae, pupae, and adults of T. castaneum and P. interpunctella were exposed to different ozone concentrations in a custom-built bench-top model of ozone-generating equipment for different durations. These preliminary trials showed that eggs were hard to kill when compared to the remainder of the life stages. Thus, eggs were selected as the test insects for the dose-response study. For the next aspect of the project, eggs of T. castaneum and P. interpunctella were exposed to 600 ppm of ozone concentration for 6-9 h. Below is the description of the experiments accomplished. Due to the word count limitation, the S. oryzae study description is omitted in this report. Insects for study Prior to the experiments, the T. castaneum was reared on a 95% whole wheat flour and 5% yeast diet mix. New colonies were established by transferring newly emerged T. castaneum adults to rearing jars and removed after 48 h. The rearing jars were incubated until the larval, pupal, or adult stages of the insect were reached and used for the experiments. For P. interpunctella eggs were loosely collected from adult moths for 48 h by inverting a jelly jar containing adult moths. The P. interpunctella eggs were reared on an artificial diet made of 1-part grower crumbles, 1-part layer crumbles, 2-parts yellow cornmeal, and ¾-part glycerol. Relevant life stages for each study were collected from master colonies started as mentioned above. Specific protocols and results: Egg experiment Prior research in our laboratory, along with other published studies have identified egg stages of stored insect pest to be more resistant to ozone due to higher metabolic inactivity of egg stages. Thus, we conducted preliminary experiments starting with the egg stage in two stored insect pests T. castaneum and P. interpunctella. For T. castaneum, twenty 1-d old eggs were placed in 118 ml jelly jars with or without 2 g food (95% whole wheat and 5% powdered yeast). A total of ten jars (five with food and the remaining five without food) were placed inside the ozone chamber and exposed to 600 ppm ozone for 6 h. Ten jars (five with food and five without food) were placed outside the chamber under laboratory conditions as a control for the same exposure time. End of 6 h of exposure, jars without food were provided with 10 g of food and the jars with food were added 8 g of food. The jars were then transferred and maintained in an incubator at 28°C and 62% RH to monitor egg survival and larval hatch. After 18 days of exposure, live larvae were counted in individual jars. The entire experiment was replicated six times. The second set of experiments exposing T. castaneum and P. interpunctella eggs to 600 ppm for 9 h (additional 3 more hours of exposure) were also conducted as discussed above and replicated six times. The experiment was a Randomized Complete Block Design (RCBD) with replication over time (blocking was done based on time). Experiments were replicated six times. At a given time for a given life stage, a total of 100 eggs were treated as 10 eggs/jar (10X10=100). These 10 jars were considered as pseudoreplicates. Thae egg that did not hatch were expressed as percentage mortality and subjected to two-way ANOVA using PROC MIXED program. Means were separated using the LS means procedure at α = 0.05. No significant differences among treatments and control were observed when eggs were exposed at 600 ppm for 6 h for T. castaneum eggs. The observation for the second experiment (600 ppm ozone for 9 h) showed significant mortality of insects exposed to ozone with or without food, for both with or without food, for T. castaneum by evaluating emerging larvae, post-treatment. For P. interpunctella eggs exposed at 600 ppm for 6 h showed considerably high mortality in ozone-treated eggs when compared to non-treated controls. The larval counts as a measure of egg survival of P. interpunctella were conducted at 15 days after ozone exposure. The results of this experiment indicated that 600 ppm ozone exposure for 9 h was sufficient to kill more than 90% of P. interpunctella eggs. Also, there were significant differences in mean larval counts among treated and control treatments (P<0.0001). Egg mortality of P. interpunctella was significantly higher in treatments exposed to 600ppm ozone for 9 has compared to control. Specific protocols and results: Surface experiments The treatment arena was constructed which consisted of a glass Petri dish (10 X 2.5 cm d X h) layered in the bottom from inside with various construction materials namely aluminum, wood, cement, and vinyl. These materials resemble the flooring of a food processing plant or the interior of a grain storage structure. Description of the surface materials is as follows. 1. Aluminum-lined Petri dishes: Aluminum sheets were cut in a circle matching the diameter of the Petri dish using scissors to fit the bottom of the dish. Non-toxic glue (Elmer's Glue-All, Columbus, OH) was used to glue the aluminum sheet firmly in the bottom of the Petri dishes. 2. Wood-lined Petri dishes: Lauan Plywood (0.52 cm thick) (Patriot timber products, Greensboro, NC), a common construction material, was cut in circles with the help of a jigsaw machine and glued to the bottom of the Petri dish using non-toxic glue. 3. Cement-coated Petri dishes: Cement (Quikrete Portland Cement, The Quikrete Companies) was mixed with tap water in order to make a slurry (1:3 water: cement). The slurry was poured into a glass Petri dish and coated uniformly on the bottom and sides of the Petri dish. The slurry was allowed to dry overnight and wetted periodically to harden the concrete mix. Cement coated Petri dish was evenly coated with 4. Vinyl-lined Petri dishes: Using scissors, bendable vinyl (0.04 cm thick) (Union Corrugating Company, Fayetteville, NC) was cut into circles and placed on the bottom of the glass Petri dish. The glue was used to attach the vinyl firmly onto the bottom of the Petri dish. 5. Glass Petri dishes (10 X 2.5 cm d X h) (Fisher Scientific) are used as the glass surfaces for experiments. Polytetrafluoroethylene (Sigma-Aldrich Co. St. Louis, MO) was evenly applied to the inside walls of Petri dishes to prevent insects from crawling outside of the arena, prior to the experiment. Eggs were exposed to ozone at 600 PPM for 9 h in the presence or absence of food. A control experiment was maintained by introducing eggs to various surfaces with or without food but not exposing them to ozone. Post-treatment, eggs were transferred to an environmental growth chamber at 28oC and 60-65% RH. Egg hatch was observed daily until 10 days. The number of eggs that hatched both in treated and control experiments was recorded. The experiment was replicated over six times (blocking was done based on time). At a given time, a total of 100 eggs were treated as 50 eggs/dish (50X2=100). These 2 dishes were considered as pseudoreplicates. Mean percentage mortality in treated arenas and corresponding control arenas, whether with diet or without food were estimated. Studies clearly showed, regardless of whether the food was present or absent in the testing arena, eggs exposed to ozone failed to hatch compared to corresponding controls. Treated surfaces did not influence the toxicity of the ozone, percentage mortality remained high and above 95% for all surfaces. Results from this study showed construction materials made of aluminum, wood, concrete, vinyl, or glass behave a similar manner in reacting to ozone. These surfaces appear to be not absorbing a significant proportion of the gas, leaving the ozone to react with the insects.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
1. Amoah, B. and R. Mahroof (2020). Disinfestation of wheat infested with Sitophilus oryzae using ozone gas. Journal of Agricultural and Urban Entomology 36(1): 35-46.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
2. Mahroof, R. (2020). Pest management in a changing world: Challenges and triumphs in the food industry. Integrated Protection of Stored Products, International Organization for Biological Control-WPRS Bulletin, 148: 66-72.
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
3. Amoah, B. and R. Mahroof (2019). Ozone as a potential fumigant for the control of Sitophilus oryzae (Coleoptera: Curculionidae) in wheat. Journal of Economic Entomology, 112 (4): 1953-1963.
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Mahroof, R. M. and Paudel S. (2021). Dose-response of selected stored product insects to ozone treated on various surface materials, In: proceedings of the 11th International Conference on Controlled Atmosphere and Fumigation in Stored Products, Jayas, D. and Jian F. (eds), Manitoba, Canada. August 23-27th, 2021, pp 303-308.
|
Progress 10/01/20 to 09/30/21
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?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 members of professional societies. How have the results been disseminated to communities of interest?Results from the project has been disseminated mainly through presenting in scientific and professional meetings, seminars and webinars. 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 and at the venue at the University. National presentations include invited seminar at the Department of Entomology, Rutgers, The State University of New Jersey, invited talk during the Annual Virtual Meeting of the South Eastern Branch of the Entomological Society of America and the Annual Meeting of the Entomological Society of America. International presentations include seminars and talks at the Faculty of Agriculture, University of Peradeniya, Sri Lanka and at the Controlled Atmosphere and Fumigation in Stored Products Conference in Manitoba, Canada. Some of our results have been published in the peer-reviewed journal and Conference proceedings. Invited talks: Mahroof, R. M. (2021). Stored-Product Pest Management in a Changing World: Challenges and Accomplishments. Invited seminar, Department of Entomology, Rutgers, The State University of New Jersey, November 19th, 2021, Webinar. Mahroof, R. M. (2021). Engaging for a Good Cause: Bugs, an HBCU and a Woman of Color in Entomology. Symposium on Diversity and Inclusion, Annual meeting of the Southeastern Branch of the Entomological Society of America, March 29-31st, 2021, Virtual Meeting. Mahroof, R. M. (2021). World of Insects. Trends in Biology Seminar Series, Department of Agricultural Biology, Faculty of Agriculture, University of Peradeniya, Sri Lanka. February 12th, 2021, Webinar. Other oral presentations: Mahroof, R. M. (2021). Effects of delayed mating on the mating performance of Lasioderma serricorne (F.). Annual meeting of the Entomological Society of America, Oct 30-Nov 3rd, 2021. Mahroof, R. M. and Paudel S. (2021). Dose-response of selected stored product insects to ozone treated on various surface materials, 11th International Conference on Controlled Atmosphere and Fumigation in Stored Products, Manitoba, WI, Canada (Virtual), Aug 23-27th, 2021. Mahroof, R. M. (2021). Stored Products Research and Teaching in Sri Lanka: My Fulbright Experiences. Annual meeting of the Southeastern Branch of the Entomological Society of America, March 29-31st, 2021, Virtual Meeting. 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 two external grain feeders, first a beetle, T. castaneum, and second a moth, P. interpunctella, was studied during the period under review. Initially, the most-ozone-tolerant life stage for each species was determined by preliminary trials. Eggs, larvae, pupae, and adults ofT. castaneumandP.interpunctellawere exposed to different ozone concentrations in a custom-built bench-top model of ozone-generating equipment for different durations. These preliminary trials showed that eggs were hard to kill when compared to the remainder of the life stages. Thus, eggs were selected as the test insects for the dose-response study. For this aspect of the project, eggs ofT. castaneumandP.interpunctellawere exposed to 600 ppm of ozone concentration for 6-9 h. Below is the description of experiments accomplished for the reporting period. Insects for study Prior to the experiments, theT. castaneumwas reared on a 95% whole wheat flour and 5% yeast diet mix. New colonies were established by transferring newly emergedT. castaneumadults to rearing jars with a wheat flour diet. The adults were removed after 48 h and the rearing jars incubated until the larval, pupal, or adult stages of the insect were reached and used for the experiments. ForP.interpunctellaeggs were loosely collected from adult moths for 48 h by inverting a jelly jar containing adult moths. TheP.interpunctellaeggs were reared on an artificial diet made of 1-part grower crumbles, 1-part layer crumbles, 2-parts yellow cornmeal, and ¾-part glycerol. Relevant life stages for each study were collected from master colonies started as mentioned above. Specific protocols and results: Egg experiment Prior researches in our laboratory, along with other published studies have identified egg stages of stored insect pest to be more resistant to ozone due to higher metabolic inactivity of egg stages. Thus, we conducted preliminary experiments starting with the egg stage in two stored insect pestsT. castaneumandP. interpunctella. ForT. castaneum, twenty 1-d old eggs were placed in 118 ml jelly jars with or without 2 g food (95% whole wheat and 5% powdered yeast). A total of ten jars (five with food and the remaining five without food) were placed inside the ozone chamber and exposed to 600 ppm ozone for 6 h. Ten jars (five with food and five without food) were placed outside the chamber under laboratory conditions as a control for the same exposure time. End of 6 h of exposure, jars without food were provided with 10 g of food and the jars with food were added 8 g of food. The jars were then transferred and maintained in an incubator at 28°C and 62% RH to monitor egg survival and larval hatch. After 18 days of exposure, live larvae were counted in individual jars. The entire experiment was replicated six times. The second set of experiments exposingT. castaneumandP.interpunctellaeggs to 600 ppm for 9 h (additional 3 more hour of exposure) were also conducted as discussed above and replicated six times. The experiment was a Randomized Complete Block Design (RCBD) with replication over time (block based on time). Experiments were replicated six times. At a given time for a give life stage, a total of 100 eggs were treated as 10 eggs/jar (10X10=100). These 10 jars were considered as pseudo replicates. Egg that did not hatch were expressed as percentage mortality and subjected to two-way ANOVA using PROC MIXED program. Means were separated using LS means procedure at α = 0.05. No significant differences among treatments and control were observed when eggs were exposed at 600 ppm for 6 h forT. castaneum eggs. The observation for the second experiment (600 ppm ozone for 9 h) showed significant mortality of insects exposed to ozone with or without food, for both with or without food, forT. castaneumby evaluating emerging larvae, post treatment. ForP. interpunctellaeggs exposed at 600 ppm for 6 h showed considerably high mortality in ozone-treated eggs when compared to non-treated controls. The larval counts as a measure of egg survival ofP. interpunctellawere conducted at 15 days after ozone exposure. The results of this experiment indicated that 600 ppm ozone exposure for 9 h was sufficient to kill more than 90% ofP. interpunctellaeggs. Also, there were significant differences in mean larval counts among treated and control treatments (P<0.0001). Egg mortality ofP. interpunctellawas significantly higher in treatments exposed to 600ppm ozone for 9 has compared to control. Specific protocols and results: Surface experiments The treatment arena was constructed which consisted of a glass Petri dish (10 X 2.5 cm d X h) layered in the bottom from inside with various construction materials namely aluminum, wood, cement, and vinyl. These materials resemble the flooring of a food processing plant or interior of a grain storage structure. Description of the surface materials are as follows. 1. Aluminum-lined Petri dishes: Aluminum sheets were cut in a circle matching the diameter of the Petri dish using scissors to fit the bottom of the dish. Non-toxic glue (Elmer's Glue-All, Columbus, OH) was used to glue the aluminum sheet firmly in the bottom of the Petri dishes. 2. Wood-lined Petri dishes: Lauan Plywood (0.52 cm thick) (Patriot timber products, Greensboro, NC), a common construction material, was cut in circles with the help of a jigsaw machine and glued to the bottom of the Petri dish using non-toxic glue. 3. Cement-coated Petri dishes: Cement (Quikrete Portland Cement, The Quikrete Companies) was mixed with tap water in order to make a slurry (1:3 water: cement). The slurry was poured intoglass Petri dish and coated uniformly on the bottom and sides of the Petri dish. The slurry was allowed to dry overnight and wetted periodically to harden the concrete mix. Cement coated Petri dish was evenly coated with 4. Vinyl-lined Petri dishes: Using scissors, bendable vinyl (0.04 cm thick) (Union Corrugating Company, Fayetteville, NC) was cut into circles and placed on the bottom of the glass Petri dish. The glue was used to attach the vinyl firmly onto the bottom of the Petri dish. 5. Glass Petri dishes (10 X 2.5 cm d X h) (Fisher Scientific) are used as glass surface for experiments. Polytetrafluoroethylene (Sigma-Aldrich Co. St. Louis, MO) was evenly applied to the inside walls of Petri dishes to prevent insects from crawling outside of the arena, prior to the experiment. Eggs were exposed to ozone at 600 PPM for 9 h in the presence or absence of food. A control experiment was maintained by introducing eggs to various surfaces with or without food but not exposing them to ozone. Post treatment, eggs were transferred to an environmental growth chamber at 28oC and 60-65% RH. Egg hatch was observed daily until 10 days. Number of eggs that hatched both in treated and control experiments were recorded. If mortality exceeds >15% in control units, then treatment mortality was corrected based on Abbott's Formula. The experiment was replicated over six times (block based on time). At a given time, a total of 100 eggs were treated as 50 eggs/dish (50X2=100). These 2 dishes were considered as pseudo replicates. Mean percentage mortality in treated arenas and corresponding control arenas, whether with diet or without food were estimated. Studies clearly showed, regardless of whether food was present or absent in the testing arena, eggs exposed to ozone failed to hatch compared to corresponding controls. Treated surfaces did not influence the toxicity of the ozone, percentage mortality remained high and above 95% for all surfaces. Results from this study showed, construction materials made of aluminum, wood, concrete, vinyl, or glass behave similar manner in reacting to ozone. These surfaces appear to be not absorbing a significant proportion of the gas, leaving the ozone to react with the insects.
Publications
- Type:
Conference Papers and Presentations
Status:
Published
Year Published:
2021
Citation:
Mahroof, R. M. and Paudel S. (2021). Dose-response of selected stored product insects to ozone treated on various surface materials, In: proceedings of the 11th International Conference on Controlled Atmosphere and Fumigation in Stored Products, Jayas, D. and Jian F. (eds), Manitoba, Canada. August 23-27th, 2021, pp 303-308.
|
Progress 10/01/19 to 09/30/20
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?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 members 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 when virtual meeting held in October, 2020. National presentations include presentations at the Virtual 2020 Annual meeting of Entomological Society of America and 14th Fumigants and Pheromones Conference (virtual, November 2020). International presentations include presentations and seminars at University of Peradeniya, Sri Lanka, Rajarata University of Sri Lanka and Embrapa Soybean in Brazil, Federal Public Research Center, Ministry of Agriculture, Livestock and Food Supply in Brazil. Some of our results have been published in the peer-reviewed journal; Journal of Agricultural and Urban Entomology, and in the proceedings of the conference of International Organization for Biological Control-WPRS Bulletin. Invited talks Mahroof, R. M. (2020). Stored Product Insect Management: From Farm to Folk. Embrapa Soybean in Brazil, Federal Public Research Center, Ministry of Agriculture, Livestock and Food Supply, Brazil, December 15th, 2020, virtual meeting. Mahroof, R. M. (2020). Stored Products Entomology for All: My Fulbright Experiences in Developing Stored Products Research and Teaching in Sri Lanka. Symposium on stored products insect management. Annual Meeting of the Entomological Society of America, November 16-19, 2020, virtual meeting. Mahroof, R. M. (2020). Tobacco beetle pheromone research and field applications. Wendell Burkholder Recognition Lecture, 14th Fumigants and Pheromones Conference. May 11-14th, 2020, Victoria Falls, Zimbabwe (Virtual meeting on October 22nd, 2020 due to COVID-19 Pandemic). Mahroof, R. M. (2020). Research in stored products entomology: Achievements, challenges and prospects. Fulbright scholar invited research seminar. Faculty of Agriculture, University of Peradeniya, March 25th, 2020, Peradeniya, Sri Lanka. Mahroof, R. M. (2020). Assessing and Grading Graduate Students: the USA perspective during the workshop on "Assessment Strategies in the Modern World",Faculty of Agriculture, University of Peradeniya, March 13, 2020, Sri Lanka. Mahroof, R. M. (2020). Stored product pest management in Sri Lanka: An update on research, teaching curriculum design and student mentoring. South and Central Asia Fulbright Conference, February 24-26th, 2020, Kochi, India. Mahroof, R. M. (2020). My experiences in stored products entomology: Am I still biting my nails? Fulbright scholar invited research seminar. Faculty of Agriculture, Rajarata University of Sri Lanka, February 14th, 2020, Anradhapura, Sri Lanka. Mahroof, R. M. (2020). Insects and Society. Fulbright Scholar invited teaching seminars. Faculty of Agriculture, Rajarata University of Sri Lanka, February11th, 2020 and Faculty of Applied Sciences, Rajarata University of Sri Lanka, February12th, 2020, Anradhapura, Sri Lanka. Other oral presentations Mahroof, R. M. (2020). Mating disruption and mating delays and subsequent effects on reproductive performance of Lasioderma serricorne (F.). Sixty sixth Annual Meeting of the South Carolina Entomological Society, Virtual Meeting, October 2nd, 2020. 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 to different surface to ozone. Findings will be published in peer-reviewed journals. Experiments will also be designed and carried out to evaluate the effect of ozone gas on food packaging materials
Impacts
What was accomplished under these goals?
The effect of ozone on two external grain feeders, first a beetle, the red flour beetle,Tribolium castaneum, and second a moth, the Indianmeal moth,Plodia interpunctella, was studied during the period under review. Initially, the most-ozone-tolerant life stage for each species was determined by preliminary trials. Eggs, larvae, pupae, and adults ofT. castaneumandP.interpunctellawere exposed to different ozone concentrations in a custom-built bench-top model of ozone-generating equipment for different durations. These preliminary trials showed that eggs were hard to kill when compared to the remainder of the life stages. Thus, eggs were selected as the test insects for the dose-response study. For this aspect of the project, eggs ofT. castaneumandP.interpunctellawere exposed to 600 ppm of ozone concentration for 6-9 h. Below is the description of experiments accomplished for the reporting period. Insects for study Prior to the experiments, theT. castaneumwas reared on a 95% whole wheat flour and 5% yeast diet mix. New colonies were established by transferring newly emergedT. castaneumadults to rearing jars with a wheat flour diet. The adults were removed after 48 h and the rearing jars incubated until the larval, pupal, or adult stages of the insect were reached and used for the experiments. ForP.interpunctellaeggs were loosely collected from adult moths for 48 h by inverting a jelly jar containing adult moths. TheP.interpunctellaeggs were reared on an artificial diet made of 1-part grower crumbles, 1-part layer crumbles, 2-parts yellow cornmeal, and ¾-part glycerol. Relevant life stages for each study were collected from master colonies started as mentioned above. Specific protocols and results: Egg experiment Prior to exposing ozone to different life stages of stored pests in different storage structures, it is required to identify the dose and duration of ozone exposure which is sufficient to kill different stages of stored insect pests. Prior researches in our laboratory, along with other published studies have identified egg stages of stored insect pest to be more resistant to ozone due to higher metabolic inactivity of egg stages. Thus, we conducted preliminary experiments starting with the egg stage in two stored insect pestsT. castaneumandP. interpunctella. ForT. castaneum, twenty 1-d old eggs were placed in 118 ml jelly jars with or without 2 g food (95% whole wheat and 5% powdered yeast). A total of ten jars (five with food and the remaining five without food) were placed inside the ozone chamber and exposed to 600 ppm ozone for 6 h. Ten jars (five with food and five without food) were placed outside the chamber under laboratory conditions as a control for the same exposure time. After 6 h, jars without food were provided with 10 g of food and the jars with food were added 8 g of food. The jars were then transferred and maintained in an incubator at 28°C and 62% RH to monitor egg survival and larval hatch. After 18 days of exposure, live larvae were counted in individual jars. The entire experiment was replicated six times. The second set of experiments exposingT. castaneumandP.interpunctellaeggs to 600 ppm for 9 h were also conducted as discussed above and replicated six times. No significant differences among treatments and control were observed when eggs were exposed at 600 ppm for 6 h forT. castaneum eggs. The observation for the second experiment (600 ppm ozone for 9 h) showed significant mortality of insects exposed to ozone with or without food. For bothT. castaneumestimated from emerging larvae. ForP. interpunctellaeggs exposed at 600 ppm for 6 h showed considerably high mortality in ozone-treated eggs when compared to non-treated controls. The larval counts as a measure of egg survival ofP. interpunctellawere conducted at 15 days after ozone exposure. The results of this experiment indicated that 600 ppm ozone exposure for 9 h was sufficient to kill more than 90% ofP. interpunctellaeggs. Also, there were significant differences in mean larval counts among treated and control treatments (P<0.0001). Egg mortality ofP. interpunctellawas significantly higher in treatments exposed to 600ppm ozone for 9 has compared to control. Specific protocols and results: Surface experiments The treatment arena was constructed which consisted of a glass Petri dish (10 X 2.5 cm d X h) layered in the bottom from inside with various construction materials namely aluminum, wood, cement, and vinyl. These materials resemble the flooring of a food processing plant or interior of a grain storage structure. The construction of the experimental arena is described below.Eggs of t. castaneum and P. interpunctella are exposed on various surfaces at a dose of 600 ppm for 9h. at the preparation of this report, the work still continues. Aluminum-lined Petri dishes: Aluminum sheets were cut in a circle matching the diameter of the Petri dish using scissors to fit the bottom of the dish. Non-toxic glue (Elmer's Glue-All, Columbus, OH) was used to glue the aluminum sheet firmly onto the bottom of the Petri dishes. Polytetrafluoroethylene (Sigma-Aldrich Co. St. Louis, MO) will be evenly applied to the inside walls of Petri dishes to prevent insects from crawling outside of the arena, prior to the experiment. Wood-lined Petri dishes: Lauan Plywood (0.52 cm thick) (Patriot timber products, Greensboro, NC), common construction material was cut in circles with the help of a jigsaw machine and glued to the bottom of the Petri dish using non-toxic glue. The inside walls of the Petri dish will be evenly coated with polytetrafluoroethylene in order to avoid insects crawling outside. Cement-coated Petri dishes: Cement (Quikrete Portland Cement, The Quikrete Companies) was mixed with tap water in order to make a slurry (1:3 water: cement). The slurry was poured intoglass Petri dish and coated uniformly on the bottom and sides of the Petri dish. The slurry was allowed to dry overnight and wetted periodically to harden the concrete mix. Cement coated Petri dish will be evenly coated with polytetrafluoroethylene inside the walls before the experiment. Vinyl-lined Petri dishes: Using scissors, bendable vinyl (0.04 cm thick) (Union Corrugating Company, Fayetteville, NC) was cut into circles and placed on the bottom of the glass Petri dish. The glue was used to attach the vinyl firmly onto the bottom of the Petri dish. Polytetrafluoroethylene was applied evenly to the sides of the Petri dishes. Glass Petri dishes (10 X 2.5 cm d X h) (Fisher Scientific) are used as glass surface for experiments. Polytetrafluoroethylene was applied evenly to the sides of the Petri dishes.
Publications
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
1. Amoah, B. and R. Mahroof (2020). Disinfestation of wheat infested with Sitophilus oryzae using ozone gas. Journal of Agricultural and Urban Entomology 36(1): 35-46.
- Type:
Journal Articles
Status:
Published
Year Published:
2020
Citation:
2. Mahroof, R. (2020). Pest management in a changing world: Challenges and triumphs in the food industry. Integrated Protection of Stored Products, International Organization for Biological Control-WPRS Bulletin, 148: 66-72.
- Type:
Journal Articles
Status:
Published
Year Published:
2019
Citation:
3. Amoah, B. and R. Mahroof (2019). Ozone as a potential fumigant for the control of Sitophilus oryzae (Coleoptera: Curculionidae) in wheat. Journal of Economic Entomology, 112 (4): 1953-1963.
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Progress 06/27/19 to 09/30/19
Outputs
Target Audience:Food processing industries, farmers, grain elevator managers, food storage warehouse managers, academics. Changes/Problems:
Nothing Reported
What opportunities for training and professional development has the project provided? This project has provided immense opportunity to explore about stored insect pests and novel approaches for their management. Moreover, the project has helped in identifying research problems in stored insect pest management and devising methods and approaches to address such problems. The project also provides opportunities for professional development to early career scientists and undergraduate students at South Carolina State University. How have the results been disseminated to communities of interest? The project is still in its preliminary stage and experiments are being conducted to establish the methods and protocols for future experiments directly linked towards the project goals and approaches to be disseminated to target audiences in multiple ways. Conferences, professional meetings, seminars, workshops, symposium, proceeding publications, peer-reviewed publications, social media, trade magazines and one-on-one conversations with industry representatives and farmers are some anticipated dissemination methods. What do you plan to do during the next reporting period to accomplish the goals?On the basis of results obtained so far during preliminary phase of the project, experiments will be conducted by exposing ozone to eggs, larvae, pupae and adults of T. castaneum, and P. interpunctella using the experimental arena constructed as explained above.
Impacts
What was accomplished under these goals?
1. Dose-time-mortality studies: Prior to exposing ozone to different life stages of stored pests in different storage structures, it is required to identify dose and duration of ozone exposure which is sufficient to kill the ozone resistant stage of stored insect pests. Since ozone is a gas and its toxicity effects depend on the amount of gas inhaled by a life stage. Gas uptake depends on a life stage's metabolic rates. Eggs and pupae are quiescent and have lower metabolic rates compared to locomotive larvae and adults. Prior researches in our laboratory, along with other published studies have identified egg of stored insect pests to be more tolerant to ozone due to slower metabolic rates. Thus, we conducted preliminary experiments starting with egg stage in two stored insect pests, red flour beetle (Tribolium castaneum (Herbst)), and Indianmeal moth (Plodia interpunctella, (Hubner)). For Tribolium castaneum, twenty 1-d old eggs were placed in 118 ml jelly jars with or without 2 g food (95% whole wheat and 5% powdered yeast). A total of ten jars (five with food and remaining five without food) were placed inside the ozone chamber and exposed to 600 ppm ozone for 6 h. Ten jars (five with food and five without food) were placed outside the chamber under laboratory conditions as a control for the same exposure time. After 6 h, jars without food were provided with 10 g of food and the jars with food were added 8 g of food. The jars were then transferred and maintained in an incubator at 28°C and 62% RH to monitor egg mortality and hatch. After 18 days of exposure, live larvae were counted in individual jars. The entire experiment was replicated for six times. Since substantial number of eggs survived at 600 ppm 6 h exposure, the experiment was further modified to increase the exposure time from 6 h to 9 h. The second set of experiment exposing T. castaneum eggs to 600 ppm for 9 h were also conducted as discussed above and replicated for six times. Observations are currently being made. Similarly, egg experiments were conducted for P. interpunctella. Preliminary studies showed that in P. interpunctella, eggs were more tolerant to ozone when compared to T. castaneum. Therefore, eggs were exposed at 600 ppm for 9 h. The experimental design and methods followed were as described for T. castaneum, except for the diet. The diet used for P. interpunctella was a mixture of 1-part grower crumbles, 1-part layer crumbles, 2-parts yellow corn mean and ¾-part glycerol. The larval counts as a measure of egg survival were conducted at 15 days after exposure. The results of this experiment indicated that 600 ppm ozone exposure for 9 h was sufficient to kill more than 90% of P. interpunctella eggs. Also, there were significant differences in mean percentage larvae among treated and control treatments (P<0.0001). Egg mortality of P. interpunctella was significantly higher in treatments exposed to 600 ppm ozone for 9 h as compared to control. 2. Construction of the experimental arena: Various treatment arena was constructed which consisted of a glass Petri dish (10 X 2.5 cm) layered in the bottom from inside with various construction materials namely aluminum, wood, cement, and vinyl. These materials resemble the flooring of a food processing plant or interior of a grain storage structure. Construction of the experimental arena are described as below. a. Aluminum-lined Petri dishes: Aluminum sheet were cut in circle matching the diameter of the Petri dish using scissors to fit to the bottom of the dish. Non-toxic glue (Elmer's Glue-All, Columbus, OH) was used to glue the aluminum sheet firmly onto the bottom of the Petri dishes. Polytetrafluoroethylene (Sigma-Aldrich Co. St. Louis, MO) will be evenly applied to the inside walls of Petri dishes to prevent insects crawling outside of the arena, prior to the experiment. b. Wood-lined Petri dishes: Lauan Plywood (0.52 cm thick) (Patriot timber products, Greensboro, NC), a common construction material was cut in circles with the help of a jigsaw machine and glued to the bottom of the Petri dish using non-toxic glue. The inside walls of the Petri dish will be evenly coated with polytetrafluoroethylene in order to avoid insects crawling outside. c. Cement-coated Petri dishes: Cement (Quikrete Portland Cement, The Quikrete Companies) was mixed with tap water in order to make a slurry (1:3 water: cement). The slurry was poured into glass Petri dish and coated uniformly on the bottom and sides of the Petri dish. The slurry was allowed to dry overnight and wetted periodically to harden the concrete mix. Cement coated Petri dish will be evenly coated with polytetrafluoroethylene inside the walls before the experiment. d. Vinyl-lined Petri dishes: Using scissors, bendable vinyl (0.04 cm thick) (Union Corrugating Company, Fayetteville, NC) will be cut into circles and placed on the bottom of glass Petri dish. Glue will be used to attach the vinyl firmly onto the bottom of the Petri dish. As stated before, polytetrafluoroethylene will be applied evenly to the sides of the Petri dishes.
Publications
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