寄主植物对甜菜夜蛾生长发育和消化酶活性的影响

通过室内饲养和生化测定,研究了甜菜、玉米和黄瓜3种寄主植物的营养物质及其对甜菜夜蛾幼虫发育、成虫产卵及5龄幼虫体内蛋白质和总氨基酸含量、淀粉酶和脂肪酶活力的影响.结果表明:与取食玉米和黄瓜的个体相比,取食甜菜的甜菜夜蛾,其幼虫期和蛹期较短,分别为11.4天和5.6天;蛹期存活率最高,达100%;成虫寿命较长,为26.3天;单雌产卵量最高,为301.8粒.取食3种寄主植物,甜菜夜蛾5龄幼虫体内的蛋白质含量无差异,但总氨基酸含量差异显著,此外,幼虫体内淀粉酶和脂肪酶活力也存在显著差异,取食甜菜的个体>取食玉米的个体>取食黄瓜的个体.取食不同寄主植物,甜菜夜蛾幼虫的消化酶和脂肪酶活力与其发育适合度呈正相关.

Effects of three kinds of host plants on development and some digestive enzyme activities of beet armyworm, Spodoptera exigua

By laboratory feeding experiments and biochemistry detection methods, the nutrition substances of three kinds of host plant (sugar beet, maize and cucumber) were detected, and the effects of these host plants on development and oviposition of beet armyworm Spodoptera exigua (Hübner), total amino acid contents and the digestive enzyme activities in the 5^th instar larvae were compared. It showed that comparing with those fed on maize and cucumber, S.exigua individuals fed on sugar beet had shorter larval and pupal periods, higher pupal survival rate, longer adult lifespan and laid significantly more eggs per female, which was 11.4d, 5.6d, 100%, 26.3d, 301.8 eggs respectively. Among the three feeding treatments, the protein contents in the 5^th instar S.exigua larvae showed no significant difference, whereas total amino acid contents, amylase and lipase activities differed significantly. According to the host plants, the amylase and lipase activities in S.exigua ranked as maize>sugar beet>cucumber. It also showed positive correlation between larval development and amylase and lipase activities in S.exigua feeding on different host plants.