Laboratory of Entomology and Agricultural Zoology, Department of Agriculture, Plant Production and Rural Environment, University of Thessaly, Phytokou str., 38446 Nea Ionia, Magnesia, Greece.
J Econ Entomol. 2012 Jun;105(3):1088-94. doi: 10.1603/ec11331.
Laboratory bioassays were carried out to evaluate the effectiveness of two formulations of spinetoram, water dispersible granules (WG), and suspension concentrate (SC-NC), against three major stored-grain beetle species, the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae); the rice weevil, Sitophilus oryzae (L.) (Coleoptera: Curculionidae); and the confused flour beetle, Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae). Adults of the above species were exposed on wheat treated with spinetoram at 1 ppm (1 mg/kg of wheat) for 0, 2, 4, 6, 8, 16, 40, and 72 h. After this interval, mortality was recorded (immediate mortality) and the surviving individuals were transferred in untreated wheat, where mortality was recorded again 7 d later (delayed mortality). Then, all adults were removed, and the number of progeny production in the untreated substrate was measured 65 d later. From the species tested, R. dominica was by far the most susceptible, given that immediate and delayed mortality for the 72-h exposure interval reached 44 and 97%, respectively. At the same time, progeny production was low, in most of the exposure intervals tested. In contrast, for S. oryzae, delayed mortality was negligible, with the exception of 72 h at the SC-NC formulation. However, in most of the cases examined, progeny production for S. oryzae was high. Finally, adult mortality for T. confusum was extremely low, regardless of the exposure interval and the type of the formulation. Nevertheless, offspring emergence of this species was low. By combining the results of the current study and the data that are available from the literature for short exposures to spinosad, we can conclude that the two ingredients were equally effective against these three stored-grain beetle species.
实验室生物测定评估了两种螺虫乙酯制剂（水分散粒剂 WG 和悬浮剂 NC）对三种主要储粮甲虫（米象、赤拟谷盗和杂拟谷盗）的防治效果。将上述三种储粮甲虫成虫暴露于经螺虫乙酯处理的小麦中，处理浓度为 1ppm（1mg/kg 小麦），暴露时间分别为 0、2、4、6、8、16、40 和 72 小时。暴露间隔结束后，记录死亡率（即刻死亡率），存活个体转移至未经处理的小麦中，7 天后再次记录死亡率（延迟死亡率）。然后，将所有成虫移除，65 天后测量未经处理基质中的后代数量。在所测试的物种中，赤拟谷盗是最敏感的，因为在 72 小时的暴露间隔内，即刻和延迟死亡率分别达到 44%和 97%。同时，在大多数暴露间隔内，后代数量很少。相比之下，米象的延迟死亡率可以忽略不计，除了悬浮剂 NC 制剂在 72 小时的暴露间隔。然而，在大多数情况下，米象的后代数量很多。最后，无论暴露间隔和制剂类型如何，杂拟谷盗成虫死亡率都极低。然而，该物种的后代数量很少。综合本研究的结果和文献中有关短时间接触螺虫乙酯的数据，我们可以得出结论，这两种成分对这三种储粮甲虫具有同等的防治效果。
