Main content area

Insecticide toxic effects on Trichogramma ostriniae (Hymenoptera: Trichogrammatidae)

Wang, Yanhua, Chen, Liping, Yu, Ruixian, Zhao, Xueping, Wu, Changxing, Cang, Tao, Wang, Qiang
Pest management science 2012 v.68 no.12 pp. 1564-1571
Lepidoptera, Trichogramma, adults, avermectins, carbamates, insect growth regulators, lethal concentration 50, neonicotinoid insecticides, organophosphorus compounds, parasitoids, pyrethrins, risk, toxicity
BACKGROUND: The parasitoid Trichogramma ostriniae (Pang and Chen) is a major natural enemy of many lepidopterans, but only a few studies have been conducted on the compatibility of biological and chemical controls. In this study, the selectivity of 30 insecticides to T. ostriniae adults was evaluated. RESULTS: Among the seven classes of chemicals tested, organophosphates and carbamates had the highest intrinsic toxicity to the wasp, with LC₅₀ values ranging from 0.032 (0.029–0.038) to 2.38 (1.91–3.15) mg AI L⁻¹. They are followed by phenylpyrazoles, avermectins, neonicotinoids and pyrethroids, which induce variable toxicity responses, with LC₅₀ values ranging from 0.14 (0.11–0.21) to 56.67 (48.94–67.24) mg AI L⁻¹, from 2.57 (1.85–4.28) to 4.48 (3.34–6.83) mg AI L⁻¹, from 2.48 (1.80–4.03) to 503.6 (457.6–557.5) mg AI L⁻¹ and from 5.44 (3.95–8.84) to 104.2 (92.48–119.7) mg AI L⁻¹ respectively. The insect growth regulators (IGRs) exhibited least toxicity to the parasitoid. CONCLUSION: Risk quotient analysis classifies neonicotinoids, avermectins, pyrethroids, IGRs and phenylpyrazoles (with the exception of butane‐fipronil and fipronil) as safe agents to the parasitoid, but categorises organophosphates and carbamates as slightly to moderately toxic or dangerous to T. ostriniae.