THE EFFECT OF INSECTICIDES ON THE LADY BEETLE CYCLONEDA SANGUINEA L. (COLEOPTERA, COCCINELLIDAE) AND ON THE APHIDAPHIS GOSSYPII GLOVER (HEMIPTERA, APHIDIDAE) ON COTTON PLANTS

ABSTRACT The ladybugs are recognized as important natural enemies of pests such as aphids and scale insects, showing excellent dispersibility in the field and may be favored with environments for refuge and by pesticide selectivity. The goal of this trial was to study the toxicity of insecticides on the predatory coccinellid Cycloneda sanguinea and on its prey, the aphid Aphis gossypii, in the cotton crop. The treatments (expressed in commercial product per hectare) were: flonicamid 500 WG at 50, 80 and 150 g, thiamethoxam 250 WG at 200 g, acetamiprid 200 PS at 150 g, imidacloprid 200 SC at 250 mL, and a control treatment without application. The evaluation of physiological selectivity was made in the laboratory and in the field, observing the effect of insecticides applied directly and indirectly on C. sanguine. The number of surviving aphids and lady beetles was evaluated before and after the application. Based on the results obtained in the laboratory and field, it was concluded that flonicamid presented the highest selectivity to C. sanguinea among the insecticides tested. All treatments were effective for aphid control and there were no significant differences among them.

摘要：
瓢虫被公认为蚜虫（aphid）、介壳虫（scale insect）等害虫的重要天敌，具备优异的田间扩散能力，偏好具有庇护场所的生境，且对选择性杀虫剂具有良好适应性。本试验旨在研究杀虫剂对棉花作物中的捕食性瓢虫Cycloneda sanguinea及其猎物棉蚜Aphis gossypii的毒性。
试验药剂以公顷用量的商品制剂计，设置如下：500 WG剂型的氟啶虫酰胺（flonicamid），用量分别为50 g、80 g和150 g；250 WG剂型的噻虫嗪（thiamethoxam），用量200 g；200 PS剂型的啶虫脒（acetamiprid），用量150 g；200 SC剂型的吡虫啉（imidacloprid），用量250 mL；另设无药剂施用的空白对照。
本研究在实验室与田间开展生理选择性评价，观察杀虫剂对Cycloneda sanguinea的直接与间接作用效果。分别于药剂施用前后统计存活蚜虫与瓢虫的数量。
基于实验室与田间试验结果，本研究得出结论：在所测试的杀虫剂中，氟啶虫酰胺对Cycloneda sanguinea的选择性最高。所有药剂处理均能有效防控蚜虫，且各处理间无显著差异。