| Both lepidopteran pests and their parasitic natural enemies can enhance their ecological adaptability by feeding on nectar sources. To screen oligosaccharides that benefit Cotesia ruficrus rather than Cnaphalocrocis medinalis, this study evaluated the effects of 12 common oligosaccharides found in nectar sources on the longevity and fecundity of C. medinalis, as well as the longevity of C. ruficrus. The results showed that feeding on the tested oligosaccharides had little effect on the longevity of C. medinalis, with the longevity of male and female adults ranging from 6.2 to 8.0 days and 5.0 to 7.9 days, respectively. Only glucose significantly increased the longevity of female adults. However, fructose (232.1), glucose (130.1), and sucrose (186.1) significantly increased the oviposition per female of C. medinalis, being 7.3, 4.1, and 5.9 times higher than that of water (31.7). Unlike C. medinalis, feeding on fructose, galactose, glucose, mannose, maltose, melibiose, sucrose, trehalose, and melezitose significantly extended the longevity of C. ruficrus adults, with longevity being 3.7, 2.9, 2.5, 2.1, 2.3, 2.0, 2.8, 2.6, and 1.7 times longer than those of the water-fed control. Therefore, galactose, mannose, maltose, melibiose, trehalose, and melezitose could significantly extend the longevity of C. ruficru adults without promoting the longevity or fecundity of its host, C. medinalis. |
