Insect Toxicology

Botanicals to enhance effectiveness of synthetic pyrethroid insecticides; funded by the U.S. Department of Defense, Deployed War Fighter Protection Program

Since the beginning of the project in April 2012, our lab has screened a wide array of plant essential oils for baseline toxicity and in combination with various synthetic pyrethroids against Aedes aegypti, the yellow fever mosquito, and Anopheles gambiae, the African malaria mosquito. To date, we have identified essential oil candidates that enhance the toxicity of various synthetic pyrethroids, and some that cause greater enhancement than the most commonly used commercial synergist in synthetic pyrethroid formulations, piperonyl butoxide (PBO).

Natural Terpenoid repellents with activity against mosquitoes, flies, cockroaches, ticks, and bed bugs

It is well established that insects and plants have shared a long evolutionary history with one another. Due to this evolutionary “arms race,” plants have developed some truly fascinating ways to deter insects from feeding upon them, such as production of various terpenoid compounds that repel or kill insect pests. Our lab is interested in isolating plant-derived compounds that may act as natural repellents.

Mechanisms of action of natural insecticides and acaricides; expression of octopamine and tyramine receptors in mammalian cell lines

Octopamine and tyramine are essential biogenic amines that have been implicated in numerous physiological systems in arthropod species, such as reproduction, the nervous system, and  learning-and-memory, to name a few. We have successfully created two stably-transfected Chinese Hamster Ovary cell lines (CHO) with a functional octopamine receptor from Periplaneta americana, the American cockroach, and a functional tyramine receptor from Rhipicephalus microplus, the southern cattle tick.

Bioassays for testing insecticides against arthropod pests

We perform various bioassay tests for various companies and agencies to quantify the ability of new insecticidal formulations to kill and repel a wide array of arthropod pest species. Some of the species we utilize in our testing includes, but is not limited too: house flies, cockroaches, ticks, bed bugs, mosquitoes, fleas, crickets, corn rootworms, corn borers, cutworms, aphids, and spider mites. The fees for service, as well as the types of testing to be performed, are negotiated via a contract basis.

Environmental Toxicology and Chemistry

Mobility of pesticides in water, sediment, plants and soils, including soil columns

Understanding mobility of pesticides is an important part of environmental toxicology and chemistry. Pesticides need to be mobile enough to allow them to be transported to the site of action. On the other hand, pesticides that are too mobile will rapidly dissipate once applied to the target area and contaminate water and sediment. Many factors can affect the mobility of pesticides in soil and water including soil characteristics, pesticide properties, and timing of application.

Fate of transgenic insecticides in soil and water, including insecticidal Bt protein toxins and vaccines

In recent years, transgenic crops have increased significantly in their usage in agriculture. Many of these crops produce insecticidal Bt proteins that target specific insect pests. As with conventional chemicals, it is important to know the fate of these insecticidal Bt proteins in the environment. The fate data is used in the risk assessment process to determine potential exposure of the insecticidal Bt proteins to non-target organisms.

Phytoremediation of pesticides in water and soil

Extensive pesticide use over several decades has resulted in the contamination of soils and water bodies. Pesticides can either these ecosystems either by intentional application, or incidentally by spray drift, surface water runoff, or spills. These pesticides may have a variety of detrimental effects on aquatic and terrestrial organisms, and could lead to disruption of the ecosystem. Cleaning up contaminated sites by conventional methods, such as excavation and storage off-site, can be expensive and not practical for areas with only minor contamination issues.

Degradation, persistence, mobility and bioavailability of veterinary pharmaceuticals in soil, water and sediment

Veterinary pharmaceuticals have emerged in recent years as a contaminant of concern in the environment. While not applied to soil and water bodies directly, veterinary pharmaceuticals enter the ecosystem after being excreted by grazing livestock or by the spreading of manue on agricultural fields as fertilizer. As with other chemicals, veterinary pharmaceuticals may have detrimental effects on aquatic and terrestrial organisms, particularly on bacteria where they may contribute to the development of antibiotic resistance.