Development, survival and reproduction of Euseius finlandicus (Acari: Phytoseiidae) at different constant temperatures

Development, survival and reproduction of Euseius finlandicus Oudemans were studied at seven constant temperatures (15, 20, 25, 27, 30, 32 and 34 degreesC) in the laboratory. Within the temperature range tested, developmental period from egg to adult varied from 148 to 360.5 h and 133.7 to 336.5 h for females and males, respectively. The lower thermal threshold for immature development for females and males was 8.9 and 6.4 degreesC, respectively. Survival during immature development exceeded 90% at all the temperatures from 15 to 32 degreesC, but at 34 degreesC an abrupt decline was recorded. Female longevity decreased gradually from 82.7 d at 15 degreesC to 12.2 d at 34 degreesC. The mean generation time ranged from 44.3 d at 15 degreesC to 15.9 d at 32 degreesC. The highest r(m) value (0.2817) was obtained at 30 degreesC and the lowest at 15 degreesC (0.0976). Temperatures above 30 degreesC had an adverse effect on population increase.