Population dynamics of sucking insects on tomato

Abstract

The incidences of three sucking insects, thrips, aphid and whitefly were studied on five tomato varieties: BARI Tomato-2, BARI Tomato-14, BARI Tomato-15, BARI Tomato-16, and BARI Tomato-17. Leaf trichomes of the tomato varieties, abundance of two predator arthropods (ladybird beetle and spider), and weather parameters (temperature and relative humidity) were correlated with the abundance of the sucking insects. The abundance of the three sucking insects and two predators showed fluctuations on the five tested tomato varieties. The aphid and whitefly prevailed in the field from the third week of November to the second week of February, and thrips were found from the last week of November to the second week of March. The predators were found in the field from the third week of November to the second week of March. The population of sucking insects showed significant negative correlations with trichomes and revealed positive relationships with relative humidity and the population of the predators. The daily mean temperature showed a significant negative correlation with thrips and a non-significant positive correlation with the population of aphids and whiteflies. Multiple linear regression analysis showed that the weather variables collectively predicted 36.7 to 47.0%, 8.1 to 31.1%, and 3.7 to 10.5%, respectively of thrips, aphid, and whitefly abundance on the five tomato varieties. The mean incidences of the thrips and aphid were significantly low on BARI Tomato-15 followed by BARI Tomato-16, whereas whitefly showed the lowest incidence on BARI Tomato-16 followed by BARI Tomato-15.