Meeting Abstract
Colony collapse disorder (CCD) is a current phenomenon which is causing rapid declines in honeybee populations. While researchers have yet to find a direct cause of CCD, it is hypothesized that it may be the result of a combination of multiple factors such as global warming, parasitic Varroa mites, and the use of pesticides. The goal of this study was to identify the effect of four commonly used pesticides in agriculture (imidacloprid, glyphosate, thiamethoxam, and clothianidin) on the immune function of honeybees. For each pesticide, 150 honeybees were collected randomly from a set of hives in the Austin area and starved for four to six hours. A pesticide sugar water solution with biological relevant concentrations was then fed to each bee with a micropipette. Bees were then left for zero (control), two, or four hours after feeding before hemolymph was extracted. Hemolymph was added to buffer, lysed with glass beads, and placed at a -80oC to stop protein activity. Samples are currently undergoing several colorimetric assays utilizing a spectrophotometer to determine immunological protein activity including a RED 660 assay for overall protein concentrations, prophenoloxidase, catalase, and peroxidase. Anecdotally, bees subjected to the pesticide glyphosate appear to have higher mortality over time compared to the other pesticides tested. Bees that ingested glyphosate had significantly lower protein concentrations than all other pesticides tested. Prophenoloxidase activity appears highest when bees are exposed to clothianidin, while imidacloprid significantly decreases activity four hours after exposure. Results from this study will help determine what effects, if any, pesticides contribute to the onset of CCD.
