关键词: 番茄潜叶蛾, 杀虫剂, 室内药效, 田间防效, 番茄

Abstract: 【Aim】 Through laboratory insecticidal effect determination and field control efficacy evaluation, the insecticides with high control efficacy against Tuta absoluta were screened to satisfy the demand for emergency control of this pest in production.【Methods】 T. absoluta larvae collected from tomato plants in the field were reared in the laboratory for more than 45 generations, the effects of 10 commonly used insecticides of seven categories including 5% emamectin benzoate water dispersible granule (WG), 60 g/L spinetoram suspension concentrate (SC) and 5% spinosad SC (antibiotics), 200 g/L chlorantraniliprole SC (bisamide), 150 g/L indoxacarb emulsifiable concentrate (EC)(oxadiazine), 10% chlorfenapyr SC (pyrroles), 240 g/L methoxyfenozide SC (hormone), 2.5% rotenone EC (botanical source), and 8 000 IU/μL Bacillus thuringiensis SC and 30 billion spores/g Beauveria bassiana wettable powder (WP)(microbial source) on the hatching rates of T. absoluta eggs and the  mortality rates of the 2nd instar larvae were determined by indoor egg-dipping method and leaf-dipping method, respectively. In July 2023, five insecticide formulations with strong insecticidal effects on T. absoluta in laboratory bioassay were sprayed to open field tomatoes in Xinjiang, Northwest China to evaluate their field control efficacy against T. absoluta. 【Results】 Laboratory bioassay results showed that the 10 pesticides had different effects on the hatching of T. absoluta eggs, the microbial insecticides 8 000 IU/μL B. thuringiensis SC and 30 billion spores/g B. bassiana WP and the botanical insecticide 2.5% rotenone EC had no significant effect on the hatching of eggs at 7 d after treatment, while the chemical insecticides 240 g/L methoxyfenozide SC, 60 g/L spinetoram SC and 5% emamectin benzoate WG exhibited significant inhibitory effects on the hatching of eggs in 5 d. The 10 pesticides had different lethal effects on the 2nd instar larvae of T. absoluta. Among the chemical pesticides, 60 g/L spinetoram SC showed the highest insecticidal activity against the 2nd instar larvae, causing 100.00% mortality rate at 1-4 d post treatment, and 10% chlorfenapyr SC and 150 g/L indoxacarb EC causing 100.00% mortality rate at 3 and 4 d post treatment, while the botanical insecticide 2.5% rotenone  EC  and the microbial insecticide  30 billion spores/g B. bassiana WP had lower lethal effects on the 2nd instar larvae during the 4-d treatment. Field experiment results revealed that the control efficacy of the tested five insecticide formulations against T. absoluta was most obvious at 7 d after application. The control efficacy of 60 g/L spinetoram SC, 200 g/L chlorantraniliprole SC and 10% chlorfenapyr SC against T. absoluta was ranked the top three, being 91.14%, 90.29% and 88.67%, respectively.【Conclusion】 Through laboratory bioassay and field control efficacy evaluation, it was found that 60 g/L spinetoram SC, 200 g/L chlorantraniliprole SC and 10% chlorfenapyr SC at their recommended dosages can be used for chemical control of T. absoluta in tomato production, which can provide guidance for the formulation of comprehensive control plans for T. absoluta and the selection of field control agents.

Key words: Tuta absoluta, insecticide, laboratory insecticidal efficacy, field control efficacy, tomato