DefinePK

Abstract

Tomato leaf miner, Tuta absoluta (Meyrick), is a highly invasive and oligophagous pest of tomato that causes severe damage to the tomato crop and threatens its production globally. Recently, in Pakistan, T. absoluta has become a major problem for the tomato crop. Considering the synthetic insecticides as first choice for its management, a laboratory study was conducted to determine the effectiveness of four different new chemistry synthetic insecticides, i.e., Chlorantraniliprole, Chlorantraniliprole + Thiamethoxam, Flubendiamide, and Spirotetramat against 3rd instar larvae of T. absoluta. Three various concentrations of each insecticide i.e., 5, 10, and 15 ppm based on their recommended field doses were used through leaf dipping method under mining (larvae inside mines) and non-mining (larvae released after the treatment) conditions. Mortality of larvae was recorded at 24, 48, and 72 hours after exposure to the insecticide. The results indicated that Chlorantraniliprole + Thiamethoxam and Chlorantraniliprole insecticides were found to be most effective against T. absoluta larvae and caused maximum mortality percentage at higher concentrations after 72 hours of exposure. Flubendiamide showed moderate effectiveness, whereas Spirotetramat exhibited minimal mortality at all concentrations, regardless of time exposure. Higher mortality was recorded on unmined leaves compared to mined leaves. According to the findings, Chlorantraniliprole + Thiamethoxam and Chlorantraniliprole alone were most effective against T. absoluta larvae under mining and un-mining leaf conditions. Chlorantraniliprole-based insecticides should be a priority in IPM, while monitoring their use and rotating them regularly can prevent resistance. Therefore, it is suggested that field trials should be conducted to determine the effectiveness of Chlorantraniliprole + Thiamethoxam and Chlorantraniliprole against T. absoluta.