Influence of temperature on life‐table parameters ofStethorus gilvifrons(Mulsant) (Coleoptera: Coccinellidae) fed onTetranychus urticaeKoch

Abstract

AbstractThe influence of temperature on life‐table parameters, fecundity and survivorship of the predatory ladybird,Stethorus gilvifrons, fed onTetranychus urticaewas determined at seven constant temperatures of 15°C, 20°C, 25°C, 28°C, 30°C, 35°C and 40°C. No development was observed at 40°C, thus being regarded as the threshold for the development ofS. gilvifrons. The results indicate a significant decrease in male and female longevity with increasing temperature from 15°C to 35°C. The longest and shortest longevity were 18.40 and 12.75 days for males and 17.40 and 8.80 days for females, respectively. The intrinsic rate of natural increase (rm) and the net reproductive rate (R0) ofS. gilvifronslinearly increased with increasing temperatures from 15°C to 35°C, while the mean generation time (T) and doubling time (DT) decreased linearly within this temperature range. The highest values ofrm(0.240 females/female/day) andR0(59.27 females/female) and the lowest mean generation time (17.01 days) and DT (2.88 days) were recorded at 35°C. The maximum (185.50 eggs) and minimum (25.50 eggs) measurement of total fecundity was also recorded at 35°C and 15°C, respectively. The results indicate that temperature greatly affected fecundity, survivorship and life‐table parameters ofS. gilvifrons, and that 35°C is a suitable temperature for population growth of this predator.