Scholarly Commons

Lethal and Sublethal Effects of Cedar Oil Derivatives on Wolf Spiders

Commercial cedar oil has been used as an insecticide and insect repellent. It contains several nicotine-like compounds that have been poorly tested for their effects on beneficial non-target species like spiders. We derived 16 compounds from cedar oil. The wolf spider Tigrosa helluo were behaviorally assayed before and after exposure to volatiles of these compounds. Spider activity and courtship latency increased among test compounds during post-trials, but we found no evidence of avoidance in choice tests. Pardosa milvina wolf spiders exposed to wet contact showed neurological responses to most compounds. Only three compounds resulted in premature mortality relative to the control over a month. We found significant sublethal and delayed lethal effects of some of these compounds on both wolf spider species. These species are abundant in crop systems. Results suggest that cedar oil derivatives used on agricultural crops could reduce the beneficial effects of biological controls in these systems.