新烟碱类杀虫剂拌种对马铃薯甲虫幼虫食物利用和生长发育的影响

为研究马铃薯甲虫Leptinotarsa decemlineata（Say）幼虫取食新烟碱杀虫剂噻虫嗪和吡虫啉处理（有效成分18 g/100 kg种薯拌种）播种90 d后马铃薯叶片的消化吸收和生长发育情况，在室内采用重量法测定了幼虫取食量、体重增加量、食物利用率，近似消化率以及蛹重等营养指标。 结果表明：70%噻虫嗪种子处理可分散粉剂拌种后，马铃薯甲虫幼虫的取食量、体重增加量、食物利用率、食物转化率、近似消化率和相对生长率以及蛹重显著低于10%吡虫啉可湿性粉剂拌种和空白对照（P＜0.05），发育历期显著长于10%吡虫啉可湿性粉剂拌种和空白对照（P＜0.05）；而10%吡虫啉可湿性粉剂拌种后，马铃薯甲虫幼虫的取食量和3～4龄期的体重增加量与空白对照差异显著（P＜0.05），蛹重、1～2龄幼虫的体重增长量、食物利用率、食物转化率、近似消化率、相对生长率和生长发育历期与空白对照差异不显著（P＞0.05）。 说明70%噻虫嗪种子处理可分散粉剂拌种对马铃薯甲虫幼虫的取食有显著抑制作用，不能很好地满足其生长发育营养物质的需要，幼虫取食其叶片后，近似消化率和相对生长速率显著降低，生长发育历期显著延长。 这有利于减少当季世代数，降低危害。

Effect of seed dressing with neonicotinoid insecticides on food utilization and development of Leptinotarsa decemlineata(Coleoptera:Chrysomelidae)larvae

In order to study digestive absorption and development of potato beetle Leptinotarsa decemlineata larvae feeding on the potato leaves grown from seed tubers （planting for 90 d） dressed with thiamethoxam and imidacloprid （18 g a.i./100 kg）, nutritional index of larvae such as food intake, body weight gain, food utilization efficiency, food conversion rate and approximate digestibility and pupal weight were tested with weighing method in the laboratory. The results indicated that the larvae feeding on the potato leaves grown from seed tubers dressed with 70% thiamethoxam ZF had significantly lower food intake, body weight gain, pupal weight, food utilization efficiency, food conversion rate, approximate digestibility and relative growth rate, and significantly longer developmental duration than those feeding on the leaves grown from seed tubers dressed with 10% imidacloprid WP and the blank control（P＜0.05）. On the contrary, seed dressed with 10% imidacloprid WP caused significant lower food intake and body weight gain in 3rd and 4th instar larvae compared with the blank control（P＜0.05）, while there were no significant difference in pupal weight, body weight gain in 1st and 2nd instar larva，food utilization efficiency, food conversion rate, approximate digestibility, relative growth rate and developmental duration than the blank control（P＞0.05）.The results suggest that 70% thiamethoxam ZF significantly inhibited larval food intake, causing it unable to meet their nutrient needs for growth and development. When L. decemlineata larvae fed on the potato leaves grown from seed tubers dressed with 70% thiamethoxam ZF, approximate digestibility and relative growth rate can be significantly reduced, and the developmental duration obviously prolonged, which may facilitate to reduce the seasonal number of generations so as to decrease the harm.