2011 Annual Report
1a.Objectives (from AD-416)
The goal is to maximize the effect of physical, chemical, and biological stressors to control stored-product insects in raw grains and processed grain products. Stored-product insect pests reduce the quality of stored grain and grain-related products in the U.S. and in the world. We will identify new methods of controlling insect pests in stored products, targeting controls to specific sites or areas, and determining how insect immune systems can be exploited to improve efficacy of new control strategies. We will identify and refine alternative insecticides, biologically-based control methods, and physical controls to manage stored-product insect pests. We will evaluate selective targeted controls and application strategies to manage insect pests in different stored-product systems.
1b.Approach (from AD-416)
Laboratory and field experiments will identify new biologically-based methods and reduced-risk insecticides to control stored-product insect pests, evaluate synergistic and additive effects from selected control agents, and to further refine physical controls, such as heat and aeration, to modify storage environments. Laboratory and field tests will investigate targeted applications of control agents, detect pathogen virulence in field populations of stored-product insects, and examine new methods for using pathogenic controls to regulate pest populations in stored products. Our research will also include detailed analysis of the cuticular lipids in the insect cuticle, and analysis of how these properties affect their response to various control agents. We will investigate how insect immune responses are regulated and how physiological responses can be interrupted and manipulated to enhance efficacy of control agents. Our research will provide new methods to control insects in raw grains and processed grain products, strategies for integrating different control agents, information on using targeted controls for specific areas within stored-product facilities, and knowledge of how the insect immune system could be exploited to improve control from reduced-risk insecticides and insect pathogens. Results will provide practical information for minimizing risk, quality deterioration, and economic damage caused by stored-product insects.
This report documents progress for the bridging parent Project 5430-43000-029-00D Integrated Management of Insect Pests in Stored Grain and in Processed Grain Products which started Mar 2010 and continued research from Project 5430-43000-025-00D Integrated Management of Insect Pests in Stored Grain and in Processed Grain Products. As part of a large cooperative study, an expert system was developed for insect pest management in bulk stored rice. Part of the research involved predicting the impacts of aeration on rough rice stored in Beaumont, TX. Results will be used to examine aeration as a management strategy in different areas where rice is stored in the south-central USA. A new study was also initiated to compare pressure versus suction aeration in wheat stored in Kansas, which will expand results generated in a previous study. Studies were conducted that assessed the interactions of pest beetles with pathogenic and putatively commensal microbes, especially as they relate to transmission and disease prevalence. This is the final report for Project 5430-43000-029-00D, which has been replaced by new Project 5430-43000-032-00D Ecology, Genomics, and Management of Stored Product Insects which started May 2011. For additional information, see the new project report.
Expert systems for management of stored rice. Expert systems utilizing population models and bin-cooling models are available for management of stored wheat and stored corn but not for stored rice. ARS researchers in Manhattan, KS, in collaboration with Texas A& M University developed a web-based system for management of the lesser grain borer and the rice weevil, two major economic pests of stored rough rice. This model was used to predict population growth of both species in unaerated rice and rice cooled at different airflow rates, for rice stored in Beaumont, TX. Predicted population growth of both species in aerated rice was about 98% less than in unaerated rice, regardless of starting grain temperatures or aeration airflow rate. This web-based system could help management programs for stored rice by increased use of aeration and potentially less usage of fumigants for insect control.
Heat treatments disinfest empty grain elevator silos. Heat treatments are being used to disinfest flour mills but there is no information on the utility of this technique to disinfest empty grain silos. ARS scientists in Manhattan, KS, in collaboration with Oklahoma State University, conducted field trials by placing live lesser grain borers, red flour beetles, or two psocid species inside containers with wheat and/or flour media and suspending those containers at different heights inside empty silos. Propane heat was generated from commercial equipment and introduced into the bottom of the silos. When temperatures exceeded 122°F for at least 6 hours, complete mortality of all insects and life stages generally occurred. Most of the insect survival occurred in the containers that were in the top or mid-points of the silos. Results show heat could be used to disinfest empty silos, but cleaning and sanitation prior to heat treatment might be necessary to maximize effectiveness.
New microbe infects insects in culture. The yellow mealworm is a pest of stored grain products, a commercial commodity as bird and lizard food, and a research model insect. It harbors a unique microbe that has escaped previous detection in spite of intensive study of the insect. ARS scientists in Manhattan, KS, discovered the microbe infecting mealworm nerve chords, fat body, and testes. They determined that it is transmitted to females during mating with infected males in which spores are bundled into sperm transfer packages. Gene sequencing showed that the organism is not closely related to any known species, but belongs to a group of protists whose evolutionary position is near the animal-fungi divergence. This research will help to understand the biology of an important insect and to develop means to improve its production or control.
Lord, J.C. 2011. Influence of substrate and relative humidity on the efficacy of three entomopathogenic fungi for the hide beetle, Dermestes maculatus. Biocontrol Science and Technology. 21(4):475-483. doi: http://dx.doi.org/10.1080/09583157.2011.552972.
Lord, J.C. 2010. Dietary stress increases the susceptibility of Tribolium castaneum to Beauveria bassiana. Journal of Economic Entomology. 103(5):1542-1546.
Arthur, F.H., Weintraub, P.G. 2010. Publications and the peer review system. American Entomologist. 56:138-139.
Lord, J.C., Vossbrinck, C.R., Wilson, J.D. 2010. Occurrence of Nosema oryzaephili in Cryptolestes ferrugineus and transfer to the genus Paranosema. Journal of Invertebrate Pathology. 105(1):112-115. doi: http://dx.doi.org/10.106/j.jip.2010.05.005.