ECOLOGICAL-STUDIES ON PARASITISM OF ERETMOCERUS-LONGIPES COMPERE (HYM, APHELINIDAE) ON THE WHITEFLY, ALEUROTUBERCULATUS-TAKAHASHI DAVID-ET-SUBRAMANIAM (HOM, ALEYRODIDAE) ON JASMINE IN FUZHOU-REGION OF THE SOUTHEASTERN CHINA

Experiments on host-stage preference, influence of temperature on para sitization, and the feeding niche of Eretmocerus longipes Compere (Hym ., Aphelinidae) parasitizing Aleurotuberculatus takahashi David et Sub ramaniam (Hem., Aleyrodidae) on jasmine were conducted both in the lab oratory of Institute of Plant Protection, Fujian Academy of Agricultur al Sciences and in the field in the Fuzhou region, Fujian Province, PR China. The results showed that the most preferred host-stage of E. lo ngipes was the 3rd instar of A. takahashi. The parasitization rate of E. longipes was significantly affected by temperature, valuing 4.8% at 18 degrees C, 27.3% at 23 degrees C, and 55.1% at 33 degrees C, respe ctively. The whitefly immature stages and the parasitoid vertically se lected all the layers of jasmine plant as their feeding niches, but th e whitefly nymph preferred to gather on the top layer, which was consi dered as its suitable feeding niche, while the parasitoid selected the middle layer as its feeding niche, To measure the ability to utilize spatial resources, the feeding niche breadth was introduced to demonst rate that the parasitoid had the less wide feeding niche breadth among the all stages tested on jasmine, which revealed that the spatial act ivity for the parasitoid was smaller than that for any stage of the wh itefly. The cluster analysis showed that the feeding niche of the para sitoid was more closely related to the 3rd instar than to any other st age of the whitefly. It was suggested that relation between the whitef ly and its parasitoid was not only depending on the host-stage prefere nce but also on the feeding niche similarity.