Comparative potency of different insecticides against Tuta absoluta (Gelechiidae) on tomato varieties in agriculture zone, Sariab, Quetta (Baluchistan) Pakistan

A study was carried out to manage tomato leaf miner (T. absulata) on exotic (Super-man) and local (Shalkot) varieties of host plant in a field plot at vegetable and seed farm, Sariab, Quetta. Chemical pesticides (Chlorfenapyr, Propenofos, Chlorpyrifos) were used and their relative efficacy against T. absulata was evaluated. The research was done in a randomized complete block design (RCBD) by performing three treatments. Two sprays of each pesticide were applied on tomato varieties. Larvae of the pest were observed before starting the treatments and mortality rate of larval forms were monitored at intervals of 1, 4, and 8 days after each spray. Results revealed that all the three pesticides showed significant control of leaf miner infestation. However, chlorfenapyr has shown best control after 1st spray after 1 and 4 days (P<0.0001) and after 8 days (P<0.001) intervals than propenofos and chlorpyrifos. Similarly, after 1 and 8 days significance level was observed to be P<0.001, and after 4 days it was P<0.0001 for shalkot variety severally. But after 2nd spray applications on both varieties significance level was noted to be higher P< 0.0001 at all intervals. It was also observed that the efficacy of all tested pesticides was below the pest injury level. It is concluded that chemical use remain the most effective control methods available to reduce T. absoluta threat levels. However, the need for alternative control methods is fortified by the presence of resistant populations as well as by the side effects of pesticides on beneficial arthropods. Even, to optimize such effective control strategies, it is necessary to understand the relationships take place between the leaf miner and its host plants.and propose recommendations for further research.