In order to assess the efficiency of different pesticides, their phytotoxicity, and the safety of natural enemies in potato fields of the Nilgiris district against the recently existing invasive pest, Liriomyza huidobrensis, two field experiments were conducted at two different locations, namely Kukkal in Kotagiri and Kappachi in Ooty, both located in the district Nilgiris, Tamil Nadu. The outcomes showed that cyantraniliprole 10.26 OD @ 75 g a.i. /ha and chlorantraniliprole 18.5 S @ 30 g a.i. /ha were helpful for managing L. huidobrensis. Following spraying, coccinellid and spider populations first declined, but gradually rose. Following it, Profenofos 50 EC @ 500 g a.i. /ha was also demonstrated to yield favourable results, but it was rejected because it significantly reduced the population of natural enemies. Additionally, it was discovered that none of the pesticides had any phototoxic effects on potato during the trial. In light of the fact that profenofos 50 EC has a similar impact on the natural enemy population as cyantraniliprole 10.26 OD and chlorantraniliprole 18.5 S @ 30 g a.i. ha-1, they can be used successfully as a management strategy for potato leaf miner.

Laboratory and pot culture experiments were conducted to assess the acute and persistent toxicity of new molecular insecticides against the notorious invasive pest of maize, Spodoptera frugiperda during 2020- 2021 at Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore. Results revealed that, the LC50 value of emamectin benzoate, chlorantraniliprole, spinetoram, flubendiamide and novaluron were 0.05, 4.08, 0.1, 85.89 and 0.91 ppm, respectively for second instar larvae and 0.03, 5.63, 0.02, 162.99 and 0.99 ppm for third instar larvae of fall armyworm. Among insecticides tested emamectin benzoate and spinetoram showed high toxicity to S. frugiperda than other insecticides by registering a minimum LC50 value. But in the persistent toxicity studies, the same insecticides showed less persistence on maize crop. Hence, insecticides like flubendiamide and chlorantraniliprole need to be recommended in the early stage of the crop period (within 20 days after sowing) and less persistent insecticides viz., emamectin benzoate and spinetoram should be recommended in the middle stage (25 to 40 days) of the maize crop for the management of S. frugiperda so that the residues may not accumulate in the harvested produce both in the stalk and grain.