Abstract: Metaphycus parasaissetiae is an important synovigenic endoparasitoid of adult Parasaissetia nigra. There is little study on the biological characteristics including behavior and habits of M. parasaissetiae adult so far. In this study, the longevity and oviposition of M. parasaissetiae were measured when the insects were supplemented with different sugar sources, with the aim to provide for the propagation and release of the wasp. Seven supplementary nutrients including 20% glucose, fructose, sucrose, trehalose, melezitose, honey, and honeydew of P. nigra were evaluated for their effects on the longevity and fecundity of M. parasaissetiae kept with or without host. The results showed that, in the absence of host, the M. parasaissetiae females fed with the sugars significantly lived longer than those fed with water or those unfed. The M. parasaissetiae females fed with fructose had the longest longevity (16.6 d); the females fed with sucrose, honey, glucose, melezitose, trehalose, and honeydew lived 13.6 d, 10.9 d, 10.6 d, 7.9 d, 7.6 d, and 4.2 d, respectively. In the presence of host, the M. parasaissetiae females fed with water, honeydew of P. nigra, melezitose, glucose, and sucrose remarkably lived longer than the unfed females. The M. parasaissetiae females fed with water had the longest lifetime (10.0 d), followed by those fed with honeydew of P. nigra, melezitose, glucose, and sucrose, with a longevity of over 9.0 d. In the absence of host, the M. parasaissetiae males fed with fructose had the longest longevity (16.0 d), and lived longer when fed with the other sugars than when fed with water and unfed. Adult nutrition significantly promoted the ovarian development and maturation of oocyte of M. parasaissetiae. M. parasaissetiae feeding on honey or sucrose with host presence or feeding on fructose without host presence had more mature ova than those feeding on water in 24 hours. The fecundity of M. parasaissetiae fed with 20% sucrose solution was the highest (43.7 eggs per female), followed by those fed with fructose, glucose, water, and honey, which were 39.0, 37.0, 31.8, and 31.0 eggs per female, respectively. The fecundity of unfed female was the lowest (12.4 eggs per female). Adult nutrition also affected the development and survival and parasitic ability of the progenies of M. parasaissetiae. In conclusion, the longevity and oviposition of M. parasaissetiae are obviously affected by the nutrition in the adult stage. Honey, fructose or sucrose at concentration of 20% are optimal supplementary nutrients for M. parasaissetiae rearing.

Key words: Metaphycus parasaissetiae, Parasaissetia nigra, sugar source, longevity, fecundity