The Effects of different temperatures on some biological properties of nephus includens kirsch (coleoptera: coccinellidae) predatory insect

36 SUMMARY Nephus includens Kirsch (Coleoptera : Coccinellidae),is one of the most effective predators of Planococcus citrl, an important citrus pest. This study was conducted to obtain some data which could be used on biological control studies of the predatory coccinellid. Development time of different immature stages, longevity, fecundity, sex ratio, starvation periods of larvae of N. Includens were determined at constant temperatures 15, 20, 25, 30, 35°C and at variable temperature 25-35°C (12 hours 25°C, 12 hours 35°C). Life tables were also constructed at 25, 30, 35, 25-35°C. The average mortalities (%) of immature stages were 55.6 36.7, 34.4, 71.6, 46.7 at 20, 25, 30, 35 and 25-35°C temperatures, recpectively. The average oviposition periods of N. includens were 45.8, 41.2, 33.8, 48.2 days at 25, 30, 35, 25-35°C, respectively. Each female laid average of 133.5, 123.0, 50.8, 123.4 eggs at 25, 30, 35, 25~35°C, respectively. Longevity was the longest at 25°C with 70 days, while 69 days at 30°C, 57 days at 35°C, 61 days at 25-35°C. The net reproduction rate (Ro) was evaluated 54.47, 35.62, 7.65, 46.07 females/female, the mean gneration time (T) was 58.36, 44.66, 37.68, 47.88 days at 25, 30, 35, 25-35°C, respectively. The intrinsic rate of increase (rm) was calculated as37 0.069, 0.080, 0.054, and 0.080 females/female/day for 25, 30, 35, 25-35°C, respectively. It was concluded that 30 and 25-35°C were found to be the most suitable temperatures for mass culture of N. includens. Because it is easy and economic to obtain 25-35°C temperature which is similar to natural condition 25-35°C is preferable temperature.