Current Projects

1. Integrative physiology of cold tolerance in insects and spiders.​  Low temperature is one of the greatest challenges faced by insects and other arthropods. We investigate the physiological and molecular mechanisms that allow insects to survive extreme winter conditions. Two ongoing projects are 1) A project sponsored by the Kentucky Science and Engineering Foundation to investigate calcium-dependent signaling mechanisms that regulate rapid cold hardening, and 2) Physiological and biochemical adaptations of winter-active wolf spiders (Genus Schizocosa). 

Model for role of calcium signaling in regulating rapid responses to cold.

The wolf spider Schizocosa ocreata feeds and hunts in the winter, making it one of the few arthropods that is active in the winter. We are investigating the physiological mechanisms that allow it to remain active at low temperature and the ecological consequences of this winter activity. Photo taken by Kevin Pfeiffer, obtained from bugguide.net.

2. Genetics and control of invasive fruit pests.  Postdoc Mark Garcia is leading projects on two invasive fruit pests, spotted wing Drosophila (Drosophila suzukii) and the Caribbean fruit fly, Anastrepha suspensa. For the Drosophila work, we are establishing populations of spotted wing Drosophila collected along a latitudinal gradient to investigate geographic variation in environmental stress tolerance and pesticide resistance. For the Caribbean fruit fly work, we are testing whether targeted overexpression of antioxidant enzymes can improve the performance of radiation-sterilized males released for Sterile Insect Technique programs.   

Spotted wing Drosophila, Drosophila suzukii

Transgenic Caribbean fruit flies expressing both blue and red fluorescent proteins. These markers are convenient for identifying which flies are transgenic, and how many copies of the transgene they carry based on their brightness.

3. Risk assessment of genetically modified insects used for Sterile Insect Technique. In a new project, we are investigating the likelihood that conditionally lethal transgenes developed for Sterile Insect Technique will fail under field conditions. Specifically, we are testing the extent to which genetic background, environmental variability, and evolutionary forces impact the effectiveness of conditionally lethal transgenes.  

Genetically modified insects are a potentially powerful tool for pest control. Our group investigates potential ecological risks associated with releasing transgenic insects.

Part of our work will address whether insects are capable of evolving resistance to genetic sterilization. Like any "pesticide," there is a strong selective pressure in favor of insects that are resistance to conditionally lethal transgenes.

4. Mechanisms of extreme freeze tolerance. We are beginning collaborative work to investigate the mechanisms of extreme freeze tolerance in insects. Studies include comparative physiology and genomics of Antarctic and sub-Antarctic midges, and the functional genomics of extreme freeze tolerance in the drosophilid fly, Chymomyza costata.

The Antarctic midge, Belgica Antarctica. This species is the only insect endemic to Antarctic and the world's southernmost insects. We are interested in the midge's ability to survive in a frozen state for nearly 9 months per year.

The drosophila fly, Chymomyza costata. Larvae of this fly are capable of surviving immersion in liquid nitrogen, making C. costata the most complex organism documented to survive at liquid nitrogen temperatures.