Effect of feeding and male presence on some biological characteristics of female Trichogramma brassicae (Hymenoptera: Trichogrammatidae)

Low prominence of natural enemies can cause suboptimal success in biological control programs. In present study, the effects of honey feeding and the availability of males were studied on the biological characteristics of Trichogramma brassicae Bezdenko. Four treatments were considered: male was available for female for merely 24 h, either with or without honey; male was continuously presented for females, either with or without honey. Twenty pairs (1 female × 1 male) of newly emerged parasitoids were placed in glass tubes and considered as the treatments. Mortality of females was recorded daily in order to indicate longevity. To determine fecundity, the emergence rate and female progeny percentage, 150 fresh Sitotroga cerealella Olivier eggs were provided for each female in the entire treatments on a daily basis. Results indicated that interaction between adult nutrition and male presence was insignificant (P > 0.01) and did not influence any of biological characteristics. Adult nutrition was more important than male presence. Honey-fed females lived 5-folds longer than the unfed females. Longevity was not significantly influenced by male presence. Fecundity of honey-fed females was 67 and 70.2 eggs; however, 18.4 and 19 eggs for unfed females. Continuous presence of male did not change fecundity. There were no significant differences in the emergence rate in all treatments and it was more than 90% for the entire treatments. Long-lived females produced more males. Percentage of female progeny was not influenced by period of male presence. Therefore, quality of parasitoids was more persuaded by diet provided rather than the period of male presence.