Lethal and sublethal effects of synthetic and bio-insecticides on Trichogramma brassicae parasitizing Tuta absoluta

• DOI: 10.1371/journal.pone.0243334
• Publication Date: 2021-07-30T13:42:08Z
• Authors: Zahra Nozad-Bonab; Mir Jalil Hejazi; Shahzad Iranipour; Mehdi Arzanlou; Antonio Biondi
• Keywords: Tuta absoluta; Trichogramma; Insecticide Resistance

The tomato leaf miner (TLM), Tuta absoluta (Meyrick), is an invasive pest found worldwide. Sustainable control strategies aimed at increasing biological approaches and decreasing chemical inputs are required, due to the tendency develop insecticide resistance. In this study, lethal sublethal effects of four insecticides (abamectin, indoxacarb, chlorantraniliprole, spinosad) entomopathogenic fungus Metarhizium anisopliae (Metschnikoff) on a widespread TLM egg parasitoid, Trichogramma brassicae Bezdenko, were estimated. Concentration mortality response bioassays enabled estimation concentrations tested for parasitoids, with chlorantraniliprole having lowest LC50 indoxacarb highest. LC25 sprayed eggs then offered three time intervals parasitoids. fertility other life table parameters individuals emerging from treated All insecticides, but not fungus, had harmful T. brassicae. applications caused 3.84-5.17 times reduction in net reproductive rate (R0) compared control. No affected by spraying 0h treatment, recorded 24 and/or 48h, except gross reproduction (GRR). value intrinsic increase (rm) also decreased 0.528-0.617 after treatments. doubling (DT) increased all treatments Nevertheless, generation (T) was only very slightly affected. addition, combination experiments, M. showed remarkable synergism controlling eggs. These results indicate that low levels key agents should be considered choice included sustainable packages.