Page Banner

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

2007 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.


4.Accomplishments
Near-Infrared Spectroscopy for Rapid Automated Detection of Insect Fragments in Flour. The milling industry routinely checks flour for insect fragments to determine whether the level is below the Food and Drug Administration (FDA) defect action level (75 fragments/50 grams flour); however, the standard chemical extraction method used to detect insect fragments in flour is costly and time-consuming. Thus, a rapid detection method is desirable. We determined that wheat infested with a single adult rice weevil contributed 67, 38, and 18 times as many fragments as wheat infested with a single small larva, large larva, or pupa, respectively. Using regression models that we developed from these data, we predicted that 1-kg samples of wheat that contained even one adult weevil would be above the Food and Drug Administration (FDA) defect action level for insect fragments, while it would take an infestation level of 390-1550 kernels (in a 1-kg sample) containing larvae or pupae to exceed the defect action level. We also determined the accuracy and sensitivity of near-infrared spectroscopy (NIRS) for detecting insect fragments in flour using three different NIR-spectrometers. The number of insect fragments predicted by NIRS was correlated with the actual number of fragments. NIRS was less precise than the standard flotation method, but it has the advantages that it is rapid, non-destructive, does not require extensive sample preparation, and can be automated for a more sophisticated sampling protocol for flour. 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 “Develop improved sampling methods for insects in static and moving bulk commodities” of subcomponent F “Detection and Monitoring of Stored-Product Insect Pests”.

Effects of Grain Type on Population Growth of the Psocids Lepinotus reticulatus and Liposcelis entomophila. Psocids are an emerging problem in grain stored in the U.S. and in grain processing facilities, yet little is known about them. We investigated the suitability of six different grains for population growth of these psocids. Lepinotus reticulatus population increase was greatest on oats, moderate on barley, milo, rice, and wheat, and least on corn. Liposcelis entomophila population growth was great on wheat and barley, was moderate on milo and rice, and was lowest on corn and oats. This study established the relative level of suitability of wheat, corn, milo, barley, oats, and rice to L. reticulatus and L. entomophila. 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”.

Beneficial Insects Control Indianmeal Moth. The Indianmeal moth is a serious pest of raw and finished stored products and attacks both packaged and bulk commodities as well as spillage. Indianmeal moth larvae can infest stored products like bags of grain, cereal, or pet food. Three species of Trichogramma wasp parasitoids were tested to find the best one for biological control of the Indianmeal moth. Indianmeal moth egg parasitism was approximately four times greater for T. deion than for T. ostriniae or T. pretiosum. Based on these findings, Trichogramma deion may be the best-suited candidate for augmentative biological control of Indianmeal moth in retail stores. This could provide a new tool for the retail organic food industry to manage insect pests. Harmless and practically invisible, Trichogramma wasps are an environmentally-friendly way to keep food pests in check. 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”.

Impact of Landscape Structure on Red Flour Beetle Distribution of Eggs. Stored-product insects live in patchy environments and the ability to find and exploit small patches of resource in structures like flour mills contributes to their pest status. Patterns of egg deposition can be used to provide insight into how beetles perceive landscapes and how landscape pattern impacts establishment and persistence of populations. The response of female red flour beetle, Tribolium castaneum, to the patchiness of flour habitat was assessed by recording their patterns of movement and egg laying on experimental micro-landscapes that varied in degree of fragmentation. Female red flour beetles responded to landscape fragmentation differently apparently depending on whether exploring or egg laying, with newly dispersing individuals visiting many habitat cells, but delaying the initiation of egg laying. Ultimately, understanding how these pests exploit the landscapes in food facilities and the critical thresholds that impact population establishment and growth, we may be better able to manipulate the environment to make it less favorable to 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 statements “Improve understanding of the abiotic factors that govern stored product insect population dynamics” and “Determine how nutritional factors and commodity quality can affect stored product pest population dynamics and pest management decisions” of subcomponent E “Biology and Ecology of Stored-Product Insect Pests”.

Evaluation of Alternative Food Sources for the Lesser Grain Borer. Capture of the lesser grain borer in pheromone-baited traps far from grain storage and earlier in the season then when grain is harvested and stored suggests the potential for this species to survive and/or reproduce in the landscape surrounding grain storages. To investigate the potential for survival on alternative hosts in the absence of grain, we conducted no-choice feeding assays with twigs and seeds of trees, and seeds of grasses, forbs, and shrubs, commonly encountered in Kansas landscapes. Adult survival was poor on grass, twigs, and forb seeds, while survival and reproduction on acorns of six species of oak was very high. These findings suggest that acorns could provide a reservour enabling populations to persist when grain is not available and potentially opens new pest management targets. 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 nutritional factors and commodity quality can affect stored product pest population dynamics and pest management decisions” of subcomponent E “Biology and Ecology of Stored-Product Insect Pests”.


5.Significant Activities that Support Special Target Populations
None


6.Technology Transfer

Number of new CRADAs and MTAs7
Number of active CRADAs and MTAs7
Number of web sites managed1
Number of non-peer reviewed presentations and proceedings16
Number of newspaper articles and other presentations for non-science audiences6

Review Publications
Atui, M.B., Flinn, P.W., Lazzari, S.M., Lazzari, F.A. 2007. Detection of Rhyzopertha dominica larvae in stored wheat using ELISA: The impact of myosin degradation following fumigation. Journal of Stored Products Research 43: 156-159.

Christen, J.M., Campbell, J.F., Lewis, E.E., Shapiro Ilan, D.I., Ramaswamy, S.B. 2007. Responses of the entomopathogenic nematode, Steinernema riobrave, to its insect hosts, Galleria mellonella and Tenebrio molitor. Parasitology 134:889-898.

Grieshop, M.J., Flinn, P.W., Nechols, J.R., Campbell, J.F. 2007. Effects of shelf architecture and parasitoid release height on biological control of Plodia interpunctella (Lepidoptera: Pyralidae) eggs by Trichogramma deion (Hymenoptera: Trichogrammatidae). Journal of Economic Entomology 99: 2202-2209.

Grieshop, M.J., Flinn, P.W., Nechols, J.R. 2006. Biological control of the Indianmeal moth on finished stored-products using egg and larval parasitoids. Journal of Economic Entomology 99:1080-1084.

Opit, G.P., Throne, J.E. 2007. Influence of maternal age on the fitness of progeny in the rice weevil, Sitophilus oryzae (Coleoptera: curculionidae). Environmental Entomology 36: 83-89.

Ramos-Rodriguez, O., Campbell, J.F., Ramaswamy, S.B. 2007. Efficacy of the entomopathogenic nematode Steinernema riobrave against the stored product insect pests Tribolium castaneum and Plodia interpunctella. Biological Control 40: 15-21.

Ramos-Rodriguez, O., Campbell, J.F., Christen, J.M., Shapiro Ilan, D.I., Lewis, E.E., Ramaswamy, S.B. 2007. Attraction behavior of three entomopathogenic nematode species towards infected and uninfected hosts. Parasitology 134: 729-738.

Toews, M.D., Campbell, J.F., Arthur, F.H. 2006. Temporal dynamics and response to fumigation of stored-product Coleoptera in a grain processing facility. Journal of Stored Products Research 42:480-498.

Vardeman, E.A., Campbell, J.F., Arthur, F.H., Nechols, J.R. 2007. Behavior of Rhyzopertha dominica (Coleoptera: Bostrichidae) in a mono-layer of wheat treated with diatomaceous earth. Journal of Stored Products Research 43: 297-301.

Weaver, D.K., Opit, G.P., Mason, L.J., Throne, J.E. 2006. Gravimetric method for determining stage of obligate internally feeding stored-product insects. Environmental Entomology 35: 1483-1490.

Campbell, J.F., Arthur, F.H. 2007. Ecological implications for post harvest integrated pest management of grain and grain-based products. In: O. Koul and G.W. Cuperus, Eds. Ecologically Based Integrated Pest Management. Oxfordshire, UK: CAB International. p. 406-431.

Kunkel, B.A., Shapiro Ilan, D.I., Campbell, J.F., Lewis, E.E. 2006. Effect of Steinernema glaseri-infected host exudates on movement of conspecific infective juveniles. Journal of Invertebrate Pathology. 93:42-49.

Last Modified: 9/1/2014
Footer Content Back to Top of Page