BIOLOGICAL STUDIES ON ERETMOCERUS-LONGIPES COMPERE (HYM, APHELINIDAE), A PARASITOID OF ALEUROTUBERCULATUS-TAKAHASHI DAVID-ET-SUBRAMANIAM (HOM, ALEYRODIDAE) IN THE LABORATORY

Experiments on the duration of development, the longevities on differe nt diets at constant temperatures, as well as the influence of constan t temperatures, relative humidities and photoperiods, on the emergence of Eretmocerus longipes Compere (Hym., Aphelinidae), a parasitoid of the citrus whitefly, Aleurotuberculatus takahashi David et Subramaniam (Hom., Aleyrodidae), were conducted separately under laboratory condi tions in Fuzhou, Fujian Province, China in 1996. The duration of the d evelopment of E. longipes from egg to adult decreased significantly as a result of an increase in temperature, ranging from 56.7 days at 15 degrees C to 11.4 days at 35 degrees C. The longevities of E. longipes were strongly interaffected by temperatures and diets being 7.9 days at 20 degrees C, 4.5 days at 25 degrees C, and 2.8 days at 30 degrees C on a honey water diet, compared to 3.1 days at 20 degrees C, 1.2 day s at 25 degrees C and 0.9 days at 30 degrees C without any food provis ion. However, no statistical difference between the provided diets of honey water or 3rd instars of the whitefly was found in longevities at the same temperature. With temperature increases in steps of 15-30 de grees C, the rate of emergence of the parasitoid increased from 44 to 89%. Relative humidity (RH) also significantly affected the rate of em ergence of the parasitoid, which varied from 20.4% at 35% RH to 76.5% at 95% RH. On the other hand, the rate of emergence of the parasitoid was not significantly different at different photoperiods, amounting t o 74.31% under total exclusion of light and 75.51% under the full ligh t condition.