PENGARUH SUHU DAN UKURAN INANG TERHADAP BIOLOGI Trichogramma sp. PARASITOID TELUR PADA Cricula trifenestrata

Abstract

The experiment was conducted to study the effect of temperature and host size on the growth and development of Trichogramma sp., a species of parasitoid which attacks Cricula trfenestrata s eggs. The experiment was carried oul in the Pesl laboratory, Dalillro, Bogor. with relative humidity ranged between 60-80%. temperature ranged.between 23-25°C, 26-28°C, and 29-3 l"C. with two kinds of different egg size (big and small). This research was conducted from March lo Sepeniber 2000, to optimize the production (generation) of Trichogramma sp. in the Laboratory. The resuts showed that some of Ihe biological index of Trichogramma sp., changed when it was cultivated in different temperature and host size. Temperature influenced longivity of parasitoid while host size influenced almost all of Ihe biological index. Although it was hardly measured, however the temperature and host size seemed to have mutual support in Influencing 7}"fcAogrximnta biological index. In low temperature, the development of parasitoid was longer than that in high temperature, while parasitoid behaviour in ovipositing was influenced by egg size. On Ihe big size host, parasitoid tended ovipositing all al once, while thai on small host ovipositing was done one by one. Ihe average of Trichogramma generation on big host was 42.1 ± 17.1 with sex ratio 1 8.8 I , while thai on small host was 73.3 ± 1 3.2 with sex ratio 6.71 I , where female was plcnticr than male. By using Birch methods, it was showed that intrinsic growth rate (r„) and net reproductive rale (Ro) on big size host were lower compared with small size host while generation lime (T) on big host was longer than small host. Ro values were significantly different belween the two hosts. The result of this experiment also showed that on both host sizes, optimum value of T, Ro and rm was achieved on 26-28°C. These results arc expected to guide parasiloid breeders lo decide the temperature and host size in mass cultivating Trichogramma sp. in laboratory. While for ield application, tempeature and hosl range arc Ihe factors should be considered.