Abdelsalam Salaheldin A, Alzahrani Abdullah M, Elmenshawy Omar M, Abdel-Moneim Ashraf M
Department of Biological Sciences, Faculty of Science, King Faisal University, Hofouf, Saudi Arabia (
Department of Zoology and Entomology, Faculty of Science, Assiut University, Egypt.
J Insect Sci. 2016 Oct 16;16(1). doi: 10.1093/jisesa/iew089. Print 2016.
The red palm weevil, Rhynchophorus ferrugineus, is of great concern worldwide, especially in the Middle East, where dates are a strategic crop. Despite their ecological hazard, insecticides remain the most effective means of control. A bioinsecticide of bacterial origin, spinosad is effective against several pests, and its efficacy against male R. ferrugineus was assessed in the present study. The antioxidative responses of key enzymes including catalase (CAT), superoxide dismutase (SOD), and glutathione-S-transferase (GST) to spinosad were investigated in the midgut and testes, and the effects of this insecticide on the cell ultrastructure of the midgut, Malpighian tubules, and testes were also determined. The lethal concentration 50 of spinosad was measured at 58.8 ppm, and the insecticide inhibited the activities of CAT, SOD, and GST in the midgut. However, no significant changes in the activities of these enzymes were observed in the testes. Spinosad treatment resulted in concentration-dependent changes in the cellular organelles of the midgut, Malpighian tubules, and testes of R. ferrugineus, and some of these effects were similar to those exerted by other xenobiotics. However, specific changes were observed as a result of spinosad treatment, including an increase in the number and size of concretions in Malpighian tubule cells and the occasional absence of the central pair of microtubules in the axonemes of sperm tails. This study introduces spinosad for potential use as an insecticide within an integrated control program against male red palm weevils. Additionally, the study provides biochemical and ultrastructural evidence for use in the development of bioindicators.
红棕象甲（Rhynchophorus ferrugineus）在全球范围内备受关注，尤其是在中东地区，那里枣椰树是一种战略作物。尽管它们具有生态危害，但杀虫剂仍然是最有效的防治手段。多杀菌素是一种细菌源生物杀虫剂，对多种害虫有效，本研究评估了其对雄性红棕象甲的防治效果。研究了过氧化氢酶（CAT）、超氧化物歧化酶（SOD）和谷胱甘肽-S-转移酶（GST）等关键酶在中肠和睾丸中对多杀菌素的抗氧化反应，并确定了该杀虫剂对中肠、马氏管和睾丸细胞超微结构的影响。多杀菌素的半数致死浓度为58.8 ppm，该杀虫剂抑制了中肠中CAT、SOD和GST的活性。然而，在睾丸中未观察到这些酶活性的显著变化。多杀菌素处理导致红棕象甲中肠、马氏管和睾丸的细胞器发生浓度依赖性变化，其中一些影响与其他外源化合物所产生的影响相似。然而，多杀菌素处理也观察到了特定的变化，包括马氏管细胞中结石数量和大小的增加，以及精子尾部轴丝中偶尔缺失中央微管对。本研究介绍了多杀菌素在针对雄性红棕象甲的综合防治计划中作为杀虫剂的潜在用途。此外，该研究为生物指示剂的开发提供了生化和超微结构证据。
