Influences of Cold Storage Period of Anagasta kuehnieela (Zeller) Eggs on Biological Parameters of Trichogramma brassicae Bezdenko

The mass production of insects is a key element in biological control programs. The most important problem in successful release programs is the cost-effectiveness of mass rearing, and release at right time. In recent years, cold-storage of biocontrol agents has been considered as an effective method for increasing survival and providing sufficient number of natural enemies for using in biological control programs. In this study the effect of cold storage of Anagasta kuehniella eggs was investigated on Trichogramma brassicae at 4 °C for 0, 1, 4, 7, 15 and 30 days in terms of life history parameters. Results showed that developmental time, longevity, fecundity, parasitism rate, emergence rate and oviposition period were significantly different (1%). The highest longevity was in control (9.56±0.66 days) while the lowest one was in 30 day treatment (5.12±0.71 days). It was also found that all population parameters except life generation time (T) differed significantly between control and cold-stored treatments. The lowest net reproductive rate (R0) (13.22±0.71) and intrinsic rate of increase (rm) (0.2178±3.80) were recorded in 30-day storage treatment. The results showed that by increasing cold-storage duration of the host eggs, the efficiency of the T. brassicae declined.