草地贪夜蛾对三种杂草的产卵和取食选择性

为探索杂草是否可作为草地贪夜蛾产卵和取食的选择对象,本试验以婆婆纳、鹅肠菜和泽漆作为测试植物,比较分析草地贪夜蛾对3种杂草的产卵及取食选择性。结果表明,以3种杂草为选择对象时,婆婆纳上卵块数(14.00块±0.58块)和卵粒数(1 305.00粒±28.16粒)显著高于其他两种杂草;以玉米和婆婆纳为选择对象时,嗜食寄主玉米上的卵块数(16.33块±0.88块)和卵粒数(1 333.00粒±28.04粒)显著高于婆婆纳(分别为12.00块±0.58块和991.00粒±24.09粒)。草地贪夜蛾1～4龄幼虫取食偏好性总体表现为玉米婆婆纳鹅肠菜泽漆,5龄和6龄幼虫对每种植物的取食选择性无明显差异。上述结果说明,在有嗜食寄主玉米时,草地贪夜蛾成虫和低龄幼虫优先选择在玉米上产卵和取食,杂草中对婆婆纳的产卵和取食偏好性显著高于其他杂草,高龄幼虫取食偏好性无显著差异。

Oviposition and feeding selectivity of Spodoptera frugiperda to three weeds

In order to find out whether weeds can be used as oviposition and feeding of Spodoptera frugiperda, the oviposition and feeding selectivity of the S.frugiperda to three weeds including Veronica polita, Myosoton aquaticum and Euphorbia helioscopia were analyzed. The results showed that the numbers of egg mass (14.00 pieces±0.58 pieces)and eggs (1 305.00 pieces±28.16 pieces) on the V.polita were the highest, which were significantly higher than those on the other two weeds; the numbers of egg mass (16.33 pieces±0.88 pieces)and eggs (1 333.00±28.04) on its favorite host corn were significantly higher than those on the V.polita (12.00 pieces±0.58 pieces and 991.00 eggs±24.09 eggs), respectively. The feeding preference of the 1st to 4th instar of S.frugiperda was Zea mays>V.polita>M.aquaticum>E.helioscopia. But for the 5th and 6th instar, their feeding selectivity for each plant was not significantly different. The results showed that the adult and young larva preferred to lay eggs and feed on Zea mays when it is available, and among the three weeds, the S.frugiperda preferred to oviposit and feed on V.polita. The elderly larvae showed no significant difference in feeding preference to corn and three weeds.