Population response to toxicants is altered by intraspecific interaction

摘要

Negative interaction between individuals is a distinctive feature of populations. The question is addressed whether the population response to toxicants(e.g., the pyrethroid pesticide fenvalerate) is altered by the strength of negative intraspecific interaction. Larvae of the trichopteran Limnephilus lunatus Curtis were exposed for 1 h to fenvalerate, then larval survival and adult emergence were monitored in outdoor stream microcosms over eight months. Degree of interaction was varied by changing larval densities. No survival was observed after 15 d at 100μ/L. Survival decreased slightly at 10μg/L when strong interaction was present.