Sobrevivência, reprodução e desenvolvimento de Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae) sob efeito de inseticidas usados em tomateiro

Abstract

Tomato crop displays great economic value to Brazil’s economy. However, the cultivation methods adopted for this solanaceae demands numerous pesticide applications for pest control. These products can be either harmful or selective to beneficial organisms, such as Coccinellidae predators. The aim of this study was to assess the physiological selectivity of insecticides registered for tomato pest control on Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae). The maximum recommended field dosage of the insecticides spinetoram, spiromesifen, methoxyfenozide, metaflumizone, tebufenozide and methomyl was used. They were sprayed on eggs, third instar larvae, pupae and adults of H. axyridis using 250 ml spray bottles; control treatment consisted of water. Methoxyfenozide didn’t reduce any biological feature of the predator. Spiromesifen only reduced survival over time when sprayed on third instar larvae. Spinetoram shortened larval period and reduced survival of adults. When sprayed on larvae, metaflumizone reduced larval survival. Tebufenozide reduced egg viability, pupal period and larval survival over time. It is concluded that methoxyfenozide, spiromesifen and spinetoram are safe to H. axyridis, and their usage should be prioritized in integrated pest management (IPM) programs; both tebufenozide and metaflumizone are harmful to some important biological features of the predator. Further studies should be performed and methomyl is highly toxic in laboratory, so its toxicity should be assessed in field and greenhouse tests to confirm its toxicity to H. axyridis.