Seasonal Incidence of Different Insect Pests and Their Natural Enemies in Tomato Ecosystem

Abstract

A field investigation was carried out to analyze the seasonal incidence of different insect pests and their natural enemies in tomato ecosystem along with their correlation with weather parameters from December, 2020 to April, 2021. A total number of 10 insect pests and 11 natural enemies were documented throughout the season. Among those insect pests recorded, tomato fruit borer, Helicoverpa armigera was the major one (49.91% relative abundance) followed by aphid, Aphis gossypii (18.62%), serpentine leaf miner, Liriomyza trifolii (16.20%) and whitefly, Bemisia tabaci (7.33%). Among the natural enemies, coccinellids were found abundantly and Coccinella transversalis recorded the highest relative abundance of 26.77% followed by Cheilomenes propinqua (10.23%), Cheilomenes sexmaculata (10.23%) and Coccinella septempunctata (9.44%). The findings of the experiment indicated that the maximum population of Helicoverpa armigera and L. trifolii was observed on the 10th SMW. While in case of A. gossypii it was observed on the 7th SMW respectively. The correlation between insect infestations and meteorological conditions demonstrated that the min temp. showed notable positive correlation with H. armigera and Aphis gossypii population and considerable negative correlation with L. trifolii. The max temp. showed noteworthy negative correlation with L. trifolii and Aphis gossypii. The morning relative humidity was found to possess significant positive correlation with L. trifolii and negative correlation with H. armigera. The evening relative humidity showed negative correlation with L. trifolii and Aphis gossypii. The study's findings provide a clear picture of the level of harm caused by insect pests in addition to helping us anticipate the seasonal occurrence of these pests for the purposes of pest monitoring and management.