Efficacy of an esfenvalerate plus methoprene aerosol for the control of eggs and fifth instars of Plodia interpunctella （Lepidoptera： Pyralidae）

Aerosol insecticides may provide an alternative to fumigants for control of the Indianmeal moth, Plodia interpunctella （Hübner）, the Indianmeal moth, a major insect pest of stored processed food. In this study, eggs and larvae （5th instars） ofP. interpunctella were exposed to aerosol applications of the pyrethroid esfenvalerate and insect growth regulator methoprene, alone and in combination, in open and obstructed positions inside small sheds. When larvae were exposed to methoprene alone, adult emergence from those exposed larvae was 7.1% ± 1.5%. In contrast, adult emergence was 92.5% ± 3.5% when larvae were exposed to esfenvalerate alone. When eggs were exposed to methoprene, adult emergence of those exposed eggs was approximately 75%; however, when eggs were exposed to esfenvalerate, adult emergence was approximately 35%. In the combination treatment of methoprene plus esfenvalerate at their respective label rates, adult emergence following larval exposure was 0.91% ±0.61% compared to 16.3% ± 9.6% when eggs were exposed. Based on our results, methoprene alone is highly effective in reducing adult emergence after larval exposure. However, it is not as effective on eggs as esfenvalerate. A combination treatment of esfenvalerate plus methoprene could be used to control eggs and the wandering-phase larval stages ofP. interpunctella. An economic risk analysis also supports a strategy of combining methoprene and esfenvalerate.

乌鲁木齐市干果储藏物害虫种类调查研究

红枣、葡萄、杏和巴旦木等特色林果业已经成为新疆尤其是南疆农民增收的重要经济来源。上述果实产品大部分被直接加工成干果出售至国内外,在新疆农业经济中占有非常重要的地位。干果产品在开放环境条件下长期储藏极易被储藏物害虫蛀食危害失去商品价值而造成损失。据资料统计损失一般可达5%~10%,损失最严重时可达100%。该研究通过走访调查和问卷调查的方法,得出乌鲁木齐市干果储藏物害虫主要种类有印度谷螟、花斑皮蠹、锯谷盗。受危害比较严重的干果有红枣、葡萄干、核桃。干果储存期在3~6个月时最容易受害虫危害。研究乌鲁木齐干果储藏物害虫种类及发生规律对于有针对性地进行害虫防治,减少经济损失具有重要意义。