779A Poster - 12. Physiology, metabolism and aging
Thursday April 07, 2:00 PM - 4:00 PM

Authors:
Becky Talyn ¹; Gabrieila Melchiorre ²; Erik Melchiorre ³

Affiliations:
1) College of Natural Sciences, California State University, San Bernardino; 2) Sage Oak Charter School; 3) Geology Department, California State University, San Bernardino

Keywords:
t. other (toxicology/critical period); b. oogenesis

Herbicides are widely used in agriculture, but many harm animals in addition to weeds. The most widely used brand of herbicide, Roundup®, occurs in multiple formulations, with proprietary ingredients, but currently all Roundup® formulations sold in the U.S. contain the active ingredient glyphosate. In this study, we determine the critical period for Drosophila melanogaster in terms of mortality and harm to the reproductive system after exposure to a Roundup® formulation with only glyphosate as an active ingredient, a Roundup® formulation that contains glyphosate and pelargonic acid, or Scythe®, an herbicide that contains only pelargonic acid as an active ingredient. For all herbicide treatments and exposure at all life stages, fewer larvae survived to adulthood than in control treatments at concentrations above 0.5 g/L. Preliminary data suggests that first instar larvae are most susceptible to mortality, regardless of herbicide exposure. Reproductive ability decreased with higher concentrations of herbicide exposure, regardless of formulation or exposure stage, possibly because survival was so low for those exposed starting at their 1^st instar. Overall, 1^st instar larvae are more susceptible to the harmful effects of exposure to both glyphosate-based and pelargonic acid-based herbicides than those exposed at later stages, and larvae of all stages are more sensitive than adults tested in previous studies with the same formulations and range of concentrations.