LIFE HISTORY TRAITS OF Neoseiulus californicus IN THE MONTHS FROM SEPTEMBER TO DECEMBER WHILE FEEDING Tetranychus urticae

Abstract

Tetranychus urticae (Acari: Tetranychidae), Koch is regarded as a destructive pest of many crops all over the world and Neoseiulus californicus is one of the most important predators of T. urticae. The aim of this study was to investigate the life history traits of N. californicus in the months of September, October, November and December when fed on T. urticae as prey. The immature development and adult performance of N. californicus were significantly differed during the studied months. Male developmental times were shorter than females in each month. The longest adult female life span, oviposition period and female fecundity observed in December whereas the shortest in September. In sex ratio, utmost number of females (0.73) was counted in October and the lowest (0.64) in December. Survivorship varied from 88.89 to 100% during immature development in October, November and December but all immatures were survived in September. From life table analysis, the highest net reproductive rate (R0 = 33.91) was found in November while the intrinsic rate of natural increase (rm = 0.39) and generation time (T=15.30) was estimated the highest in December. The finite rate of increase was found maximum as λ=1.74 whereas the gross reproductive rate was minimum (GRR=29.66) in September. Based on these results, we cautiously expect that the biological traits of N. californicus are effective to control T. urticae.