Abstract:
Spiders play an important role in agricultural ecosystems by preying upon pest populations. The present study investigated the field populations of an important biological control agent, Neoscona theisi. They were collected from seven different areas of Pakistan (Bahawalpur, Kasur, Lahore, Multan, Nawabshah, Okara, and Sheikhupura). The specimens were tested for susceptibility to technical grade (98.6%) and formulated Imidacloprid (25% wettable powder WP) using dip method. LC50 of imidacloprid for each preparation was estimated by probit analysis. Mortality data for 24, 48 72 and 96 hours after exposure was recorded. Results showed that populations of N. theisi collected from cotton growing areas (Bahawalpur, Multan, Nawabshah, Okara) were more resistant to imidacloprid with higher LC50 values than populations from the wheat growing areas (Kasur, Lahore, Sheikhupura). Effects of imidacloprid remained stable through time. Maximum mortality was observed after 24 hours of exposure but afterwards populations became stable against Imidacloprid. Values of hazard quotients (HQ) calculated for both preparations of insecticide for all studied populations of N. theisi were less than 2 which were considered to characterize a low risk to non-target arthropods. Therefore this study suggested that there is little risk of Imidacloprid to studied spider species and both can be utilized in integrated pest management programs.
Page(s):
289-296
DOI:
DOI not available
Published:
Journal: Biologia, Volume: 62, Issue: 2, Year: 2016