The effects of different temperatures and relative humidity on the development, mortality and nymphal predation of Anthocoris minki

Mass rearing techniques are a necessity in developing a suitable and economic biological control method. Anthocoris minki Dohrn (Heteroptera: Anthocoridae), which is successfully reared for use in biological control, is a promising indigenous Anthocoris species for biological control of Agonoscena pistaciae Burckhardt and Lauterer (Homoptera: Psyllidae) in pistachio orchards. Development time of nymphal instars, mortality percentage and prey consumption of A. minki fed on Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs were studied at three constant temperatures (20, 25 and 30 +/- 1A degrees C) and two relative humidity levels (40 and 65 A +/- 5%) under laboratory conditions. Temperature and r.h. significantly affected development time and nymphal prey consumption of A. minki. Duration of incubation and total nymphal development time decreased significantly with each increase in temperature. Total nymphal development time of A. minki at 40% and 65% r.h. was 18.6 and 18.6 days at 20A degrees C; 13.7 and 14.6 days at 25A degrees C; and 10.8 and 11.8 days at 30A degrees C, respectively. The shortest nymphal development time and highest nymphal mortality percentage were recorded at 30A degrees C and 40% r.h. The lowest nymphal mortality was 30.1% and 32.1% at 40% and 65% r.h., respectively, at 25A degrees C; the highest nymphal mortality was 51.5% and 52.1% at 20A degrees and 30A degrees C, respectively, and 40% r.h. The highest average number of E. kuehniella eggs consumed was 123.1 at 20A degrees C and 65% r.h., and the lowest was 86.4 at 30A degrees C and 40% r.h. during nymphal development time of A. minki.