Reproduction of Nesidiocoris tenuis reared on Ephestia kuehniella eggs and Bemisia tabaci nymphs

Abstract: A project aimed at developing an augmentative biological control programme for Bemisia tabaci (Gennadius) and Thrips palmi Karny using an indigenous strain of Nesidiocoris tenuis (Reuter) is under way in Japan. As a fundamental part of this project, the development, survival and reproduction of N. tenuis were studied in the laboratory using Ephestia kuehniella Zeller eggs and B. tabaci nymphs as diets. Both diets were provided on tomato leaf sections to study immature development and survival. Tomato leaflets with petioles were used as oviposition substrates in oviposition experiments. For immature stages reared on E. kuehniella eggs, development time and survival rate at 25 °C were similar to those of the Spanish strain studied previously. The daily oviposition rate of the Japanese strain was greater than that of the Spanish strain. For immature stages reared on B. tabaci nymphs, development time at 25 °C was longer than that of those reared on E. kuehniella eggs. The fecundity of female adults reared on E. kuehniella eggs was greater than that of those reared on B. tabaci nymphs. However, when the predator was fed B. tabaci nymphs, its intrinsic rate of natural increase was greater than when it was fed E. kuehniella eggs. The lower developmental threshold and the thermal constant were estimated based on the developmental times for N. tenuis reared on B. tabaci nymphs at 20 °C, 25 °C and 30 °C. The lower developmental threshold was much higher than that of the Spanish strain. In conclusion, B. tabaci nymphs are as suitable as E. kuehniella eggs as diets for the successful reproduction of N. tenuis.