Laboratory experiments were conducted in Pakistan to investigate the effectiveness of the diatomaceous earth (DE) formulation, Protect-It, at 150 ppm and imidacloprid, at 1.25, 2.5 and 5.0 ppm, alone or in combination, against the rusty grain beetle, Cryptolestes ferrugineus Stephens (Coleoptera: Laemophloeidae), the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and the psocid, Liposcelis paeta Pearman (Psocoptera: Liposcelididae). The bioassays were conducted at 25 °C, 65% relative humidity (r.h.) and continuous darkness by using adults of each insect pest that were exposed on treated or untreated wheat, rice and maize. Adult mortality counts were performed 1, 2, 4 and 7 days post-exposure. Progeny production was also evaluated 62 and 30 days after the last mortality count for beetles and psocid respectively. Results showed that mortality was increased with the increase of dose and exposure interval. Imidacloprid was more effective at the highest dose than the DE alone. The combination of DE plus imidacloprid resulted to higher mortalities than DE or imidacloprid alone at almost all exposure intervals. There was higher mortality on wheat than on rice or maize. In general, T. castaneum was the most tolerant insect species to any treatment while L. paeta was the least tolerant. The highest progeny production was observed for T. castaneum (i.e., 33.1 individuals per vial) while the lowest for L. paeta (i.e., 11.1 individuals per vial) on maize treated with Protect-It alone. The findings of the current study indicate that the combined use of DE and imidacloprid, as wheat, rice and maize protectants, may provide adequate level of management to several important stored-product insects.

在巴基斯坦进行了实验室实验，研究了单独或组合使用的硅藻土（DE）制剂Protect-It（150 ppm）和吡虫啉（1.25、2.5和5.0 ppm）对生锈的甲虫（Cryptolestes ferrugineus）的有效性斯蒂芬（鞘翅目：Laemophloeidae）时，谷蠹，Rhyzopertha蠹（F.）（鞘翅目：Bostrychidae），红色面粉甲虫，赤拟谷盗（秋天）（鞘翅目：拟步甲科）和psocid，嗜paeta皮尔曼（Psocoptera：Liposcelididae）。通过使用暴露在经过处理或未经处理的小麦，水稻和玉米上的每种害虫的成虫，在25°C，相对湿度（rh）和连续黑暗条件下进行生物测定。暴露后1、2、4和7天进行成人死亡率计数。最后一次对甲虫和psocid的死亡率进行计数后62和30天，还评估了子代产量。结果表明，死亡率随着剂量和暴露间隔的增加而增加。吡虫啉在最高剂量下比单独的DE更有效。在几乎所有暴露时间间隔内，DE加吡虫啉的组合导致的死亡率高于单独使用DE或吡虫啉的死亡率。小麦的死亡率高于水稻或玉米。一般来说，锥栗是对任何处理方法耐受性最高的昆虫，而帕氏乳杆菌的耐受性最低。观察到最高的后代生产的赤拟谷盗（即每瓶33.1人），而最低的为L. paeta（即每瓶11.1人）的玉米与保护，它单独处理。当前研究的结果表明，将DE和吡虫啉作为小麦，水稻和玉米的保护剂，可以对几种重要的贮藏昆虫提供适当的管理水平。