The effect of temperature on the biology of Phytoseiulus macropilis (Banks) (phytoseiidae) in applied biological control program

Abstract

Phytoseiulus macropilis (Banks) (Phytoseiidae) is a natural enemy of Tetranychus urticae Koch (TSSM), a common pest in several cultures, especially in greenhouses. This research aimed to know the biological parameters of a strain of P. macropilis from Vale do Taquari, State of Rio Grande do Sul, feeding on TSSM at different temperatures. The study was initiated with 30 eggs individualized in arenas under the temperature of 20, 25 and 30 ± 1°C and relative humidity of 80 ± 10%. The average length (T) of each generation decreased with the increase of temperature, ranging from 25.71 days at 20°C to 11.14 days at 30°C. The net reproductive rate (Ro) ranged from 45.47 at 20°C to 18.25 at 30°C; the innate capacity for increase (rm) was 0.15 at 20°C, reaching 0.26 at 30°C and the finite increase rate (λ) ranged from 1.41 to 1.82 females day-1 at 20 and 30°C, respectively. In the present study, it was observed that the strain of the evaluated predatory mite from mild climate of South Brazil, might present a good performance to control TSSM when exposed to a temperature range between 20 and 30°C.