Density and seasonal dynamics of Bemisia tabaci and its predators in different agricultural landscapes in South China

Abstract

Bemisia tabaci is the main pest of agriculture in many regions of the world. The resistance of whitefly to pesticides has increased as a consequence of the continuous irrational use of wide-spectrum pesticides. Thus, pesticides are no longer always effective as a long-term control method. The agricultural landscape can affect the occurrence of an insect population. The objective of this study was to clarify the occurrence of whitefly and its predators in tomato fields in different agricultural landscapes. Different landscapes are classified into urban, flower, water, and mountain landscapes by the principal component analysis method. In 2018–2019, whitefly had the longest main activity period and the lowest density in the flower landscape. The water landscape helped to maintain the highest densities of whitefly during the main activity period. Nine species of predators were sampled, and Nesidiocoris tenuis, Chrysoperla sinica, Menochilus sexmaculata, and Harmonia axyridis were the dominant species throughout the sampling season in both years. During the main activity period, N. tenuis had the highest density in all sampled landscapes. The density of the dominant predators was the highest in the flower landscape, and each natural predator had the largest temporal niche width in the 2-year sampling period. Bemisia tabaci, N. tenuis, and M. sexmaculata were highly synchronized temporally. The flower landscape showed satisfactory results in suppressing whitefly. Increasing the proportion of flowering plants and increasing the diversity of plant crops in the agricultural landscape can effectively reduce the densities of whitefly during an outbreak.

Genome-Wide Identification and Expression Analysis of the Cytochrome P450 Gene Family in Bemisia tabaci MED and Their Roles in the Insecticide Resistance

“…B. tabaci do direct damage by feeding on plant sap and indirect damage by transmitting plant viruses to vegetable crops [ 4 , 5 , 6 ]. Because of its ability to transmit begomoviruses and criniviruses very efficiently into many vegetable crops [ 7 , 8 , 9 , 10 ], farmers respond with calendar application of insecticides, often with insecticides sharing the same mode of action, resulting in resistance development in exposed populations [ 11 , 12 ].…”

Effects of short-term extreme temperature treatment on the development and reproductive capacity of Encarsia formosa

“…Bemisia tabaci inflicts direct harm on crops by extracting plant sap and excreting honeydew, which leads to sooty mold and significantly impairs plant photosynthesis. Indirect damage also occurs through the transmission of various plant viruses ( Li et al, 2022 ). The economic losses from indirect damage considerably exceed those caused by direct feeding ( Zhang X M et al, 2020 ).…”