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United States Department of Agriculture

Agricultural Research Service

Related Topics

Research Project: INTEGRATED MANAGEMENT OF INSECT PESTS IN STORED GRAIN AND IN PROCESSED GRAIN PRODUCTS

Location: Stored Product Insect Research Unit

2007 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.


4.Accomplishments
• Pathogenic fungi can control stored-product insects. Fungi that infect only insects can be used for environmentally benign pest control, but they are often dismissed as inappropriate for the dry conditions of stored products. Scientists at the Grain Marketing and Production Research Center tested Beauveria bassiana, a fungus that is registered for insect control on crops, by comparing efficacy against stored grain insects under various moisture conditions. The fungus’ efficacy for larvae of the Indianmeal moth and adults of the rice weevil and maize weevil was greatest under dry conditions that caused desiccation stress. Moisture conditions did not affect the fungus’ performance for adults of the rusty grain beetle or larvae of the cigarette beetle or sawtoothed grain beetle. The red flour beetle, a pest that is difficult to control with any available technology, was found to be most susceptible to the fungus under dry conditions that caused desiccation stress. The stress was confirmed by exposure to desiccation prior to exposure to the fungus and by low weight gain. These results demonstrate that dry stored-grain conditions are favorable for B. bassiana efficacy against many stored-product pests and will provide a basis for exploring their physiological vulnerabilities with molecular methods. This research addresses National Program 304, Crop Protection and Quarantine, Component II, Biology of Pests and Natural Enemies (Microbes), Section A., Basic Biology: Identification of key factors that influence the development and other life processes of pests and their natural enemies.

• Hull hardness in rough rice is a barrier to insect attack. In most cereal grains kernel hardness is correlated with resistance to damage from the lesser grain borer, however, the hull of rough rice could offer some level of protection. Scientists at the Grain Marketing and Production Research Center in Manhattan, KS, exposed young larvae of the lesser grain borer on different rice types with solid hulls, cracked hulls, and brown rice with the hull removed, and analyzed kernels for hardness and amylose content. More larvae entered the kernel and developed to the adult stage when the hulls were cracked, but there was no differences in kernel hardness, amylose content, or hulled rice that were related to larval development. This study shows that sound hulls are a barrier to lesser grain borer larvae, and that the characteristics of the kernel may not be important in determining risk or susceptibility to this insect. This research addresses National Program 304, Component IV Crop Protection and Quarantine, Stored Product Insects, Section E. Biology and Ecology of Stored Product Insects: Determining how nutritional factors and commodity quality can affect stored product pest population dynamics and pest management decisions.

• Insect growth regulator methoprene affects eggs of the lesser grain borer. One of the insecticides used to control the lesser grain borer on stored rice is the insect growth regulator methoprene, and while this insecticide limits development of immature insects, we have limited information regarding direct toxicity to eggs of the lesser grain borer. Scientists at the Grain Marketing and Production Research Center in Manhattan, KS, exposed eggs of the lesser grain borer on filter paper and on rice treated with methoprene, and also exposed adults on treated rice. Mortality of eggs increased as the concentration of methoprene on filter paper increased, and eggs exposed directly on rice either failed to hatch, or larvae died before they could penetrate the hull, or died inside the kernel and did not reach the adult stage. When adult females were exposed on rice treated with methoprene, egg-laying was reduced. Results show that eggs of the lesser grain borer are extremely sensitive to methoprene, and it could be used effectively in management programs that are targeted toward this insect. This research addresses National Program 304, Component IV Crop Protection and Quarantine, Stored Product Insects, Section G. Development of New and Improved Control Technologies: Determining new control technologies and improving existing control technologies, including combined use of different control technologies.

• Rice varieties vary in susceptibility to stored-grain insects. Scientists at the Grain Marketing and Production Research Center in Manhattan, KS, in cooperation with scientists at the University of Arkansas in Fayetteville, AR, exposed adult lesser grain borers and rice weevils on several cultivars of long-grain and medium-grain rice from several growing locations. Progeny production of both species and resultant feeding damage varied with both rice types and with the specific cultivar and location, but the physical characters we measured were not correlated with progeny production. Location and cultivar were important in determining the susceptibility of rough rice to the lesser grain borer and the rice weevil, but this susceptibility probably relates more to the condition of the exterior hull than the physical characteristics of the kernel itself. This research addresses National Program 304, Crop Protection and Quarantine, Component IV Stored Product Insects, Section E. Biology and Ecology of Stored Product Insects: Determining how nutritional factors and commodity quality can affect stored product pest population dynamics and pest management decisions.


5.Significant Activities that Support Special Target Populations
None


6.Technology Transfer

Number of new CRADAs and MTAs2
Number of active CRADAs and MTAs3
Number of non-peer reviewed presentations and proceedings12

Review Publications
Toews, M.D., Campbell, J.F., Arthur, F.H., Ramaswamy, S.B. 2006. Outdoor flight activity and immigration of Rhyzopertha dominica into seed wheat warehouses. Entomologia Experimentalis et Applicata 121: 73-85.

Tilley, D.R., Casada, M., Arthur, F.H. 2007. Heat treatment for disinfestation of empty grain storage bins. Journal of Stored Products Research. 43:221-228.

Mohandass, S.M., Arthur, F.H., Zhu, K.Y., Throne, J.E. 2007. Biology and management of Plodia interpunctella (Lepidoptera: Pyralidae) in stored products. Journal of Stored Products Research 43: 302-311.

Lord, J.C. 2006. Detection of Mattesia oryzaephili (Neogregarinorida: Lipotrophidae) in grain beetle laboratory colonies with an enzyme-linked immunosorbent assay. Journal of Invertebrate Pathology 94: 74-76.

Arthur, F.H., Bautista, R.C., Siebenmorgen, T.J. 2007. Influence of growing location and cultivar on Rhyzopertha dominica (F.) and Sitophilus oryzae (L.) infestation of rough rice. Insect Science 14: 231-239.

Butts, C.L., Dorner, J.W., Brown, S.L., Arthur, F.H. 2006. Aerating farmer stock peanut storage in the southeastern u.s.. Transactions of the ASAE. 49(2):457-465.

Chanbang, Y., Arthur, F.H., Wilde, G.E., Throne, J.E. 2007. Efficacy of diatomaceous earth to control Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) in rough rice: Impacts of temperature and relative humidity. Crop Protection. 26(7): 923-929. Doi: http://dx.doi.org/10.1016/j.cropro.2006.08.009.

Lord, J.C. 2007. Enhanced efficacy of Beauveria bassiana for the red flour beetle, Tribolium castaneum, with reduced moisture. Journal of Economic Entomology 100: 1071-1074.

Last Modified: 7/25/2014
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