Meeting Abstract

59.4  Sunday, Jan. 5 14:15  Differential impacts of organic and synthetic pesticides on the non-target organism Caenorhabditis elegans and the target organism Termitoidae MULALY, L.E.*; O’LEARY, F.A.; St. Edward’s University, Austin, TX lmulaly@stedwards.edu

Synthetic pesticides are manufactured to mimic organic pesticides but typically persist longer in the environment. Pesticides are absorbed into soil and affect non-target organisms like C. elegans, a nematode. In this study, we compared the impact of the organic pesticide pyrethrum to its synthetic counterpart, cypermethrin. We also examined effects of combining each pesticide with an organic synergist, parsley seed oil (PSO), a common agricultural practice. We tested the effects on C. elegans and on the target organism, Termitoidae (termites). OP50 E. coli was prepared with each pesticide treatment (pyrethrum, cypermethrin, pyrethrum+PSO and cypermethrin+PSO each in three ratios, PSO alone) at the highest sub-lethal concentration of pesticide (5 μg/mL). After C. elegans cultures were exposed, motility and lifespan were assessed. Motility was assessed via a thrashing assay in M9 buffer. Lifespan was determined by age-synchronizing worms, exposing them to pesticide, then transferring them to egg-laying inhibitor plates. No statistically significant differences in lifespan or motility between treatment groups were found. However, PSO had detrimental effects on C. elegans development, suggesting high vulnerability early in life. Termites were exposed to the same pesticide treatments and tested for lifespan. An ANOVA determined that all termites exposed to PSO, cypermethrin or a combination had significantly shorter lifespans than control termites. Our data suggests that addition of PSO increased the detrimental impact of cypermethrin and pyrethrum on C. elegans and termites. This can be used in environmentally conscious practice to eliminate termites with a biodegradable pesticide treatment, reducing the pesticide’s persistence in soil.