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United States Department of Agriculture

Agricultural Research Service

Related Topics

Research Project: ECOLOGY, SAMPLING, AND MODELING OF INSECT PESTS OF STORED GRAIN, PROCESSING FACILITIES, AND WAREHOUSES

Location: Stored Product Insect Research Unit

2008 Annual Report


1a.Objectives (from AD-416)
This project proposes to develop better tools to monitor insect populations; to improve IPM strategies for managing insects in stored grain, food processing facilities, and warehouses; to investigate the dispersal patterns that insects utilize to avoid treatments and to reinfest facilities; and to conduct investigations on emerging pests. The primary goal of the research is to reduce losses in quality to grain and grain products caused by insects. To achieve this goal, the following research objectives will be investigated:.
1)improve methods for detecting insects in raw grain and other products by determining the critical factors that affect trap catch, and the relationship between trap catch and actual level of product infestation;.
2)determine how the spatial distribution and population structure of stored-product insects inside and outside processing facilities before, during, and after control treatments affects re-infestation potential;.
3)develop models that predict insect population growth in grain processing facilities and warehouses, and use the models to investigate optimal IPM strategies; and.
4)determine the prevalence and pest potential of psocids and grain mites in stored grain, processing, and warehouse facilities, and conduct ecological studies on those emerging pests that prove to be economically important to implement monitoring and control strategies.


1b.Approach (from AD-416)
Laboratory and field experiments will be conducted to improve insect detection, sampling, and monitoring techniques in raw grain, grain processing facilities, and warehouses. We will improve interpretation of pheromone monitoring programs by determining the important factors that influence trap capture of walking beetles in grain processing facilities and warehouses, and optimize the accuracy of pheromone traps in locating red flour beetle infestation sources. We will characterize the factors responsible for pest resurgence after fumigation or other treatments; determine how spatial distributions of insect pests change before, during, and after control treatments; evaluate how long-term population dynamics of stored-product pests influences pest resurgence following treatment; and assess the potential for pests to survive in food residues and to avoid treated areas during or after control treatments. We will develop computer simulation models for insect pests of grain processing facilities and warehouses, and use these models to optimize monitoring and management strategies. Spatial simulation models will be developed for the red flour beetle, warehouse beetle, and Indianmeal moth. We will investigate the ecology and potential economic impact of emerging pest species, such as psocids and grain mites. Determine the prevalence of these pests in grain storages and mills and develop monitoring and control strategies for species that prove to be economically important.


3.Progress Report
We developed molecular markers to DNA fingerprint 16 different red flour beetle populations in the USA. This will allow us to determine how flour mills become infested and strategies to reduce reinfestation rate. The long-term population dynamics of insects in flour mills was evaluated. This data will be very important in understanding how population resurgence occurs following different treatments such as sanitation, fogging, heat treatments, and traditional fumigation. We developed a model for the red flour beetle in flour mills. Data from the previously mentioned studies is being used to validate the model. The model will be an important tool to evaluate different pest management strategies for the red flour beetle, which is the primary insect pest of flour mills. We studied biological control methods for the Indianmeal moth. We found that one species of Trichogramma wasp was very effective in parasitizing Indianmeal moth eggs. Trichogramma was less effective when the Indianmeal moth eggs were laid in food residues. We studied the influence of food residues on red flour beetle pheromone trap catch. Food residues tended to increase trap catch. We compared two species of psocids for heat treatment mortality. One species, Liposcelis entomophila was two times more tolerant than the other probably due to heat shock proteins that protect L. entomophila. We also tested the susceptibility of two species of psocids to several surface insecticides. Cyfluthrin and chorfenapyr were effective against both species; however, pyrethrins were not as effective. These accomplishments address Component IV “Postharvest, Pest Exclusion, and Quarantine Treatment” of National Program 304 “Crop Protection and Quarantine.”


4.Accomplishments
1. Development of molecular population genetic tools for evaluating sources of red flour beetle infestation. Red flour beetle is the major pest of commercial flour mills, but the sources of these beetles are not well understood. We developed protocols to DNA fingerprint different red flour beetle populations and collected populations from 16 commercial food facilities around the United States. This work has enabled us to DNA fingerprint individual beetles collected in traps even if beetles are dead and the DNA has become degraded. This new technology is allowing us to evaluate population structure, sources of infestation, and levels of movement from one area to another, and should greatly improve pest monitoring programs and allow more targeted pest control applications. This accomplishment addresses Component IV “Postharvest, Pest Exclusion, and Quarantine Treatment” of National Program 304 “Crop Protection and Quarantine”, and specifically addresses the action plan problem statement “Improve and optimize pheromone/food traps for monitoring stored product pest insect populations” of subcomponent F “Detection and Monitoring of Stored-Product Insect Pests”.

2. Impact of Spillage on Red Flour Beetle Response to Pheromone Traps. Pheromone traps are widely used in food facilities to monitor stored-product insect activity, but the influence of the distribution and amount of food residues in a facility on trap capture efficiency is not known. The response of red flour beetle to pheromone traps was evaluated when placed into environments with differing amounts and distribution of food material. Movement patterns of red flour beetles were affected by the amount of flour present. The proportion of beetles trapped was greater when flour residues were present compared to no flour residues. These findings suggest that patterns of flour residues can influence the chances of a beetle being caught in a pheromone trap; and thus, could affect the interpretation of pheromone based monitoring programs. This accomplishment addresses Component IV “Postharvest, Pest Exclusion, and Quarantine Treatment” of National Program 304 “Crop Protection and Quarantine”, and specifically addresses the action plan problem statement “Improve and optimize pheromone/food traps for monitoring stored product pest insect populations” of subcomponent F “Detection and Monitoring of Stored-Product Insect Pests”.

3. Beneficial Insects Control Indianmeal Moth. Indianmeal moth is a serious pest of both raw and finished stored products like bags of grain, cereal, or pet food. We determined how different substrates affected the ability of three different species of beneficial insects to parasitize and kill Indianmeal moth eggs. The study was conducted in Petri dishes that were either empty, contained flour, or millet. The beneficial insect, Trichogramma deion, parasitized more Indianmeal moth eggs than the other two species in the empty dishes and in the dish containing flour. Parasitism was consistently low for all three species in the millet-filled dishes. Trichogramma deion may be the best-suited for use as a biological control agent for Indianmeal moth. Trichogramma could provide a new tool for the retail organic food industry to manage insect pests. This accomplishment addresses Component IV “Postharvest, Pest Exclusion, and Quarantine Treatment” of National Program 304 “Crop Protection and Quarantine”, and specifically addresses the action plan problem statement “Determine how the interactions of pests and other organisms, particularly natural enemies, affect stored product pest population dynamics and pest management decisions” of subcomponent E “Biology and Ecology of Stored-Product Insect Pests”.

4. Susceptibility of psocids to heat. Psocids, or booklice, are emerging pests of stored products, such as in grain storages and flour mills. Heat treatments are increasingly used to control insects in flour mills, and there is no information on efficacy of heat for controlling psocids. We tested susceptibility of two species of psocids, Liposcelis entomophila and Lepinotus reticulatus, to heat, and we determined whether heat shock proteins, which are proteins which protect other proteins in the bodies of animals during stress, play a role in tolerance to heat in these two species. Liposcelis entomophila was over 2-fold more heat tolerant than L. reticulatus. We found heat shock proteins only in Liposcelis entomophila, which might explain its greater tolerance to heat treatment and its more common occurrence in warmer parts of the world. Our results indicate that heat treatments should be efficacious for control of both of these psocid species. This accomplishment addresses Component IV “Postharvest, Pest Exclusion, and Quarantine Treatment” of National Program 304 “Crop Protection and Quarantine”, and specifically addresses the action plan problem statement “Determine pest status of insect species, particularly emerging pests” of subcomponent E “Biology and Ecology of Stored-Product Insect Pests”.

5. Psocid response to surface insecticides. Psocids, or booklice, are emerging pests of stored products, such as in grain storages and flour mills. Previous studies have shown low to moderate efficacy of insecticides used for controlling psocids on concrete surfaces in flour mills. We tested susceptibility of two species of psocids, Liposcelis bostrychophila and L. entomophila, to three insecticides applied to experimental concrete surfaces, and also the sublethal effect of these insecticides on the mobility of these species. The insecticides beta-cyfluthrin and chlorfenapyr showed high short-term efficacy against both psocid species, unlike pyrethrins. Liposcelis bostrychophila was slightly more tolerant than L. entomophila to all three insecticides. Behavioral assays indicated that the insecticides reduced the mobility of both species and that pyrethrins elicited weak repellence in L. bostrychophila. Lower mobility observed in L. bostrychophila may be a contributing factor to its higher insecticide tolerance. Beta-cyfluthrin and chlorfenapyr, unlike pyrethrins, were effective against both psocid species and should be useful tools for management of these pests. This accomplishment addresses Component IV “Postharvest, Pest Exclusion, and Quarantine Treatment” of National Program 304 “Crop Protection and Quarantine”, and specifically addresses the action plan problem statement “Determine pest status of insect species, particularly emerging pests” of subcomponent E “Biology and Ecology of Stored-Product Insect Pests”.

6. Long-Term Population Trends of Stored-Product Insects at Flour Mills Evaluated. There is limited data available on the long-term population trends of stored-product insects in food processing facilities or the impact of pest management tactics on pests in the field, and this information is critical for the development of integrated pest management programs. To develop a better understanding of the geographic variation in insect population dynamics in commercial food processing and storage sites, a monitoring system was developed that facilitated the collaboration between USDA scientists and onsite personnel. We collected trapping data from multiple locations across the country. This data will be used to develop population models of pests in the field, and will be used to evaluate the efficacy of different insect management options. Technology developed to improve the efficiency of trapping programs may also be adopted by the pest management industry. This accomplishment addresses Component IV “Postharvest, Pest Exclusion, and Quarantine Treatment” of National Program 304 “Crop Protection and Quarantine”, and specifically addresses the action plan problem statement “Improve and optimize pheromone/food traps for monitoring stored product pest insect populations” of subcomponent F “Detection and Monitoring of Stored-Product Insect Pests”.


5.Significant Activities that Support Special Target Populations
None


6.Technology Transfer

Number of Non-Peer Reviewed Presentations and Proceedings3
Number of Newspaper Articles and Other Presentations for Non-Science Audiences5

Review Publications
Flinn, P.W., Hagstrum, D.W., Reed, C., Phillips, T.W. 2007. Stored Grain Advisor Pro: Decision support system for insect management in commercial grain elevators. Journal of Stored Products Research 43: 375-383.

Grieshop, M.J., Flinn, P.W., Nechols, J.R., Scholler, M. 2007. Host-foraging success of three species of Trichogramma (Hymenoptera: Trichogrammatidae) in a simulated retail environment. Journal of Economic Entomology 100: 591-598.

Toews, M.D., Perez-Mendoza, J., Throne, J.E., Dowell, F.E., Maghirang, E.B., Arthur, F.H., Campbell, J.F. 2007. Rapid assessment of insect fragments in flour milled from wheat infested with known densities of immature and adult Sitophilus oryzae (L.) (Coleoptera: Curculionidae). Journal of Economic Entomology 100: 1714-1723.

Ramos-Rodriguez, O., Campbell, J.F., Lewis, E.E., Shapiro Ilan, D.I., Ramaswamy, S.B. 2007. Dynamics of carbon dioxide release from insects infected with entomopathogenic nematodes. Journal of Invertebrate Pathology 94: 64-69.

Casada, M., Ram, M.S., Flinn, P.W. 2008. Thermal Design of Shipping Containers for Beneficial Insects. Applied Engineering in Agriculture 24: 63-70.

Ni, X., Gunawan, G., Brown, S.L., Sumner, P.E., Ruberson, J.R., Buntin, G., Holbrook Jr, C.C., Lee, G., Streett, D.A., Throne, J.E., Campbell, J.F. 2008. Insect-attracting and antimicrobial properties of antifreeze for monitoring insect pests and natural enemies in stored corn. Journal of Economic Entomology. 101:631-636.

Opit, G.P., Throne, J.E. 2008. Effect of diet on population growth of the psocids Lepinotus reticulatus and Liposcelis entomophila. Journal of Economic Entomology 101: 616-622.

Opit, G.P., Throne, J.E. 2008. Population growth and development of the psocid Lepinotus reticulatus at constant temperatures and relative humidities. Journal of Economic Entomology 101: 605-615.

Grieshop, M.J., Flinn, P.W., Nechols, J.R., Campbell, J.F. 2008. Effects of fine grain habitat complexity on egg parasitism by three species of Trichogramma. Journal of Biological Control 45: 328-338.

Last Modified: 10/1/2014
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