Mewis I, Ulrichs C
Research Office, Central Luzon State University, Munoz, Nueva-Ecija 3120, Philippines
J Stored Prod Res. 2001 Apr;37(2):153-164. doi: 10.1016/s0022-474x(00)00016-3.
Environmental and human health problems associated with the use of synthetic pesticides have prompted the demand for non-polluting, biologically specific insecticides. The current study tested the use and action of diatomaceous earth against several stored product pests. Fossil Shield(R) applied to wooden plates was lethal to adult Tenebrio molitor and Tribolium confusum, but larvae of the mealworm were unaffected. Beetles died within 14 days exposure in the absence of food to a dose of 2 and 4 g/m(2), but mortality was reduced in those fed grain bran. Fossil Shield(R) was lethal to first instar larvae of Plodia interpunctella, but not lethal to older larval stages. Two-week old larvae of T. confusum were more sensitive to diatomaceous earth than P. interpunctella at the same age. Contact with diatomaceous earth caused adult Sitophilus granarius, T. molitor and T. confusum to lose weight and reduced their water content, suggesting disruption of "the water barrier". Death of stored product insects treated with diatomaceous earth decreased with increased r.h., due to reduced transpiration through the cuticle. High r.h. delays, or above 60% can prevent, the drying action of diatomaceous earth.
与合成农药使用相关的环境和人类健康问题促使人们对无污染、具有生物特异性的杀虫剂产生需求。当前的研究测试了硅藻土对几种仓储害虫的作用。施用于木板上的“化石护盾”对黄粉虫成虫和杂拟谷盗成虫具有致死性，但黄粉虫幼虫未受影响。在没有食物的情况下，暴露于2克/平方米和4克/平方米剂量的甲虫在14天内死亡，但喂食麦麸的甲虫死亡率降低。“化石护盾”对印度谷螟初孵幼虫具有致死性，但对老龄幼虫阶段不具有致死性。在相同年龄时，两周大的杂拟谷盗幼虫比印度谷螟幼虫对硅藻土更敏感。与硅藻土接触导致谷蠹成虫、黄粉虫成虫和杂拟谷盗成虫体重减轻且含水量降低，这表明“水屏障”受到破坏。由于通过表皮的蒸腾作用降低，用硅藻土处理的仓储害虫死亡率随相对湿度升高而降低。高相对湿度会延迟硅藻土的干燥作用，相对湿度高于60%时可阻止其干燥作用。
