Abstract: 【Objective】The objective of this study is to investigate the effect of host-feeding on the egg load and longevity of parasitoid Diglyphus isaea, and to understand the reproductive biology and promote the reproduction potencies of this parasitoid. 【Method】 Female parasitoids were dissected to assess egg load, three factors affecting the egg loads of D. isaea females were examined. These factors are the age of adult parasitoid (i), the host stage utilized (ii) and the size of host-feeding meal (iii). Daily observations were provided the longevity of the host-feeding adult. 【Result】 This parasitoid emerged from their hosts without mature eggs, after given only a carbohydrate diet, they began mature eggs. At day 5, the egg load was 7.5, much higher compared to others, then gradually resorbed after 6 days. The eggs load and eggs laid were significantly higher in parasitoids exposed to 3rd instar larvae of Liriomyza sativae, which were 5.82 and 2.85, respectively. This parasitoid matured more eggs when they were fed on 3rd instar larvae of host on day 3, day 5 and day 7 after emergence. The longevity of the parasitoid feeding on 1st larvae, 3rd larvae and honey feeding was 28.3, 29.26 and 26.8 d, respectively, and no significant difference between them. 【Conclusion】 Host feeding would increase the egg maturation, not prolong the longevity of the parasitoid D. isaea.

Key words: Diglyphus isaea , egg maturation , longevity , mass rearing