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United States Department of Agriculture

Agricultural Research Service

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IIBBL Scientists
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Dawn Gundersen-Rindal (Research Leader)

Research focuses on microbial biological control technologies for the control of lepidopteran pests of significance to U. S. agriculture crops and forests. My primary focus is parasitic wasp-associated viruses, known as polydnaviruses, which are pathogenic to the gypsy moth pest larval stage. Polydnaviruses are not able to replicate outside of the wasp and are produced only by female wasps from a provirus form integrated in the wasp genome. Polydnaviruses are co-injected with eggs into the pest larvae hosts during oviposition, where the polydnavirus shuts down the immune system and development of the pest and facilitates parasitoid survival. I am using both genomic and functional genomic approaches to understanding how polydnaviruses and their pathogenic genes regulate their host and negatively disrupt pest insect hosts so that they can be exploited for this use. I am also conducting pest host genome analysis to develop a database index of expressed gypsy moth genes. These indexed genes will be screened for pest response to infection and regulation by polydnaviruses and other microbial pathogens, including baculoviruses, bacteria (Bacillus thuringiensis), and fungi. This information will be used to identify specific vulnerabilities within the gypsy moth to infection by microbial pathogens, which will speed discovery of how they work and lead to improved effective biopesticides for lepidopteran pests. This will enable pest biological control strategies minimizing use of chemical insecticides.  

Michael Blackburn (Research Entomologist)

Conducts research to identify new bacterial pathogens of insects that can be used to control pests, and characterizes insecticidal toxins produced by these bacteria. Economical methods for screening large numbers of bacteria for the ability to kill insects are developed. The interactions between insects and their bacterial pathogens are studied in an effort to improve the efficiency of the pathogens. Research is also conducted on interactions between the normal gut bacteria of pest insects and pathogens of these insects. Bacteria that typically occur in the insect gut may suppress the growth of pathogens, providing the pest with protection against infection. Insect pests used in these studies include the gypsy moth, tobacco budworm, diamondback moth, and Colorado potato beetle.

 

John Carroll (Entomologist)

I conduct research to identify and evaluate chemicals that repel ticks or modify their behavior in ways that prevent tick bites. This research involves cooperation with the EPA to develop standardized methods for evaluating tick repellents and demonstrating their efficacy for product registration.   Research is also underway to investigate methods of suppressing populations of the blacklegged tick (deer tick), vector of the pathogen causing Lyme disease, and the lone star tick, also of medical and veterinary importance.   Additional studies focus on tick host-finding behavior and ecology as they relate to tick control.

 

Kamlesh (Kamal) Chauhan (Research Chemist)

Research involves discovery and development of behavior modifying compounds of insect pest and arthropod vectors of disease. Identification and synthesis of bioactive molecules, modification of natural products for enhanced biological potency, and develop economical and environment friendly approach to prepare novel bioactives are key attributes of insect management strategy we pursue. Another area of my research is conservation and augmentation of predators and parasitoids through manipulation of chemical messages they use to find each other and their prey or hosts. Implementation of my research will reduce the nation's reliance on chemical inputs to produce food and fiber, and will provide better personal protection against arthropod-borne diseases.

 

Joseph (Dick) Dickens (Research Entomologist)

Specializes in insect sensory physiology and behavior, in general, with current investigations of: chemical signals emitted by the Colorado potato beetle and in its host plants which modify behavior of the beetle and associated insects, neural and molecular mechanisms of olfaction in the Colorado potato beetle and other insects.   Collaborates with field entomologists and plant molecular biologists to implement discoveries as components of novel, biorational, environmentally-sound pest management.

 

Mark Feldlaufer (Research Entomologist)

There has been a huge resurgence of bed bug (Cimex lectularius) populations in the United States and abroad and our research program focuses on the control of these annoying, blood-sucking pests. Specific research is directed at evaluating synthetic and natural products for their efficacy in controlling or repelling bed bugs, including the determination of any residual activity putative toxicants may possess. Since bed bug eggs are for the most part refractory to chemical treatment, we are also interested in evaluating compounds for ovicidal activity.   Large colonies of bed bugs are maintained by in vitro membrane feeding (non-human, non-animal) to ensure sufficient biological material is available for laboratory studies.

 

Matthew Greenstone (Research Entomologist)

We use molecular methods to quantify arthropod predation and parasitism of insect pests; our goal is to manipulate natural enemy populations so that those biocontrol agents found to be most effective through molecular assay can be made more abundant and effective. We use the polymerase chain reaction (PCR) to detect prey DNA in the guts of arthropod predators, or insect parasitoid DNA in the bodies of insect hosts. Our assays target the Cytochrome Oxidase I gene which, besides being capable of separating very closely related insect species, has been proposed as a universal “barcode” for all living things, analogous to the DNA fingerprints used in human forensic investigations. We use DNA barcodes to identify immature predators, most of which cannot be identified by other means. Knowing the identities of immature as well as adult predators enables a more complete characterization of predator assemblages and, thereby, a more complete understanding of the role of predators in biological control.  

 

Robert Harrison (Research Molecular Biologist)

Baculoviruses are insect viruses that can kill harmful insects on plants without the need to use chemical insecticides.  However, each baculovirus only infects and kills one or a few related insect pests, which limits the success of baculoviruses as pest control agents. Research is directed towards obtaining a more complete understanding of the baculovirus genes involved in baculovirus infectivity and insecticidal activity.  I hope to develop ways to improve the scope and performance of baculovirus-based pesticides.  

 

Ashot Khrimian (Research Chemist)

Identification and development of synthetic pheromones and other behavior modifying compounds for indigenous and invasive insect species, such as brown marmorated stink bug, browntail moth, Mediterranean fruit fly, oriental fruit fly, emerald ash borer, etc.  These chemicals will be used as attractants for monitoring and possibly control of pest insects.

    

Susan Lawrence (Research Molecular Biologist)

Research focus is examining the effect of insect feeding on plants with the goal of producing plants that respond to insect attack by expressing a genetically modified gene that makes the plants resistant to the insect. Currently we are examining the response of potato and tomato to Colorado potato beetle and the effects of corn rootworm on corn. For example we have identified numerous genes that are affected by Colorado potato beetle and will isolate their regulatory regions and test if they respond to insect feeding. Finally we will construct a new gene containing the regulatory region of the feeding induced gene and an insecticidal gene. Placed into potato this new plant will contain Colorado potato beetle feeding inducible resistance. Identification of new genes conferring resistance to insect pests is also a goal of our lab. Currently we are expressing the putative insecticidal gene in bacteria in order to produce large quantities of the protein. This protein is fed to insects to test its ability to deter insects. Once a promising gene is found it will be placed into a plant and tested for insect resistance.

 

Phyllis Martin (Research Microbiologist)

Research goal is to control pest insects such as Colorado potato beetles, southern corn rootworms, diamondback moths, and gypsy moths. These pest insects can defoliate crops and trees, destroy root systems, reduce crop marketability through crop damage, and transmit plant diseases. Investigate the pathogens that cause lethal bacterial diseases of these pest insects and develop techniques to discover new insect pathogens, and to facilitate the screening of these bacteria. The bacteria involved are naturally occurring and are compatible with organic farming. One of the bacteria under study, the crystal forming Bacillus thuringiensis (Bt), was discovered more than one-hundred years ago as a disease in a silkworm colony. Many strains of this type of bacteria are very toxic to caterpillar pests.  Other strains are toxic to the immature forms, or larvae, of mosquitoes.  A few strains also kill beetle larvae.  Several scientists in the lab, as a team, have also discovered a strain of violet bacteria, Chromobacterium subtsugae(Chromo) that kills beetles, whiteflies, and stink bugs. A patent was issued in July of 2007 on this strain and we are continuing research to discover how it kills insects.

 

Don Weber (Research Entomologist)

Research focus is insect behavioral ecology with a commitment to improvement of pest management.   Lab’s research program focuses on leaf beetles which are agricultural pests, such as corn rootworms, cucumber beetles, and Colorado potato beetle.   This effort involves the evaluation of environmentally-friendly tactics such as native biological controls and changes in tillage and cover cropping to suppress key pests such as Colorado potato beetle. This beetle is the most important insect defoliator of potatoes in North America and Europe , and also an important pest of tomato and eggplant crops.   Because the beetle has evolved pesticide resistance repeatedly, chemical control techniques developed against this pest have not provided long-term protection of potato crops.   Non-chemical complements and alternatives will provide more sustainable tactics as part of an improved pest management strategy for both organic and conventional vegetable growers.

 

Aijun Zhang (Research Chemist)

Research program is focused on chemical communication systems of insect pests and other arthropods and development of effective means to prevent or suppress them that affect human well-being and to enhance the safety and quality of life for the U.S. public.  It includes study on sex pheromone and plant host attractant systems of moths, flies, yellow jackets, beetles, mealybugs, cockroaches, etc. Research is being conducted with use of electroantennogram, chemical synthesis, and other state of the art techniques to identify the chemical components that are behaviorally active in attracting or repelling insects and making the synthetic version of those natural products for behavior tests.   Efforts are made with all projects to transfer knowledge and techniques to applied programs on the control of pest species.

 

 

 

 

 

 

 


Last Modified: 8/26/2013