Crop Protection Research Centre, Department of Advanced Zoology and Biotechnology, St. Xavier's College (Autonomous), Palayamkottai 627 002, Tamil Nadu, India.
Toxicon. 2011 Oct;58(5):415-25. doi: 10.1016/j.toxicon.2011.06.001. Epub 2011 Jul 18.
Rhynocoris marginatus is a predominant and potential reduviid predator of many economically important pests in India. The venomous saliva (VS) was collected by milking method and diluted with HPLC grade water to prepare different concentrations (200, 400, 600, 800 and 1000ppm). The VS from R. marginatus was found to be toxic and the LD(50) of the VS in Spodoptera litura third instar were 768 and 929ppm at 48 and 96h for microinjection and oral toxicity studies, respectively. Level of hydrolase and detoxification enzymes significantly decreased in a dose-dependent manner after treating the host with VS for 96h. A decrease in carbohydrate (21%) and lipid (46%) contents and an increase in the protein content (50%) were prominent in the experimental category. The VS reduced the relative growth rate, approximate digestibility, efficiency of conversion of ingested and digested food of S. litura in the oral toxicity study. Salivary venom inhibits the haemocytes from aggregation and affects spreading behavior of haemocytes separated from the fifth stadium larvae of S. litura. The result showed that VS toxins caused mortality, changed the nutritional indices, and altered the levels of macromolecule quantity and digestive enzymes of S. litura. We concluded that the VS of R. marginatus is venomous to a prey species, S. litura.
横纹芫菁是印度许多重要经济害虫的主要潜在捕食性芫菁，其毒液（VS）通过挤奶法收集，并用 HPLC 级水稀释，制备不同浓度（200、400、600、800 和 1000ppm）。研究发现，横纹芫菁的 VS 具有毒性，在微注射和口服毒性研究中，VS 对斜纹夜蛾三龄幼虫的 LD(50)分别在 48 和 96h 时为 768 和 929ppm。用 VS 处理宿主 96h 后，水解酶和解毒酶的水平呈剂量依赖性显著降低。实验组碳水化合物（21%）和脂质（46%）含量减少，蛋白质含量（50%）增加。VS 降低了斜纹夜蛾在口服毒性研究中的相对生长率、近似消化率、摄入和消化食物的转化率效率。唾液毒液抑制血细胞聚集，并影响从斜纹夜蛾五龄幼虫分离的血细胞的扩散行为。结果表明，VS 毒素导致斜纹夜蛾死亡，改变了其营养指标，并改变了斜纹夜蛾大分子数量和消化酶的水平。我们得出结论，横纹芫菁的 VS 对猎物斜纹夜蛾具有毒性。
