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Chinese Journal of Biological Control ›› 2023, Vol. 39 ›› Issue (1): 18-28.DOI: 10.16409/j.cnki.2095-039x.2022.03.007

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Population Dynamics of Bemisia tabaci and Its Dominant Natural Enemies on Summer Tomato under Different Planting Environments

LI Mingjiang, YANG Shaowu, SHANG Haopei, ZHOU Shunwen, LIU Jihuan, LI Guitao, CHEN Guohua, ZHANG Xiaoming   

  1. College of Plant Protection, Yunnan Agricultural University, Kunming 650201, China
  • Received:2022-01-02 Online:2023-02-08 Published:2023-02-21

Abstract: Population dynamics of Bemisia tabaci and its dominant natural enemies were investigated in open tomato fields and greenhouse tomato fields in Yuanmou county, Yunnan province, using five-point sampling method. Further, the temporal niche index and grey correlation index were used to analyze the temporal and spatial following relationship between B. tabaci and its dominant natural enemies. The results showed that the population densities of nymphs and adults of B. tabaci in the open fields were higher than those in the greenhouse tomato fields. The proportion of female B. tabaci in the greenhouse tomato fields was significantly higher than that in the open tomato fields during whole sampling period. The population densities of B. tabaci nymphs were the highest at the middle leaves of the plants in both the tomato fields, while those of B. tabaci adults were the highest at the upper leaves. Nesidiocoris tenuis, Menochilus sexmaculatus, Encarsia formosa and Eretmocerus hayati were the dominant natural enemies of B. tabaci in both the open and the greenhouse tomato fields. Harmonia axyridis was also dominant in the open tomato fields. The population density of dominant natural enemies in the open fields was higher than those in the greenhouse tomato fields. The ratio of natural enemies to B. tabaci in the open tomato fields was higher than that in the greenhouse fields. Menochilus sexmaculata and B. tabaci shared the greatest temporal niche overlap indexes in the open and greenhouse tomato fields, with values of 0.96 and 0.99, respectively. Menochilus sexmaculata and B. tabaci showed the closest following relationship, with the grey correlation index of 0.33 and 0.36, respectively, in the open and greenhouse tomato fields. In view of the aggregation habit of B. tabaci, the control can focus on the middle and upper parts of the plants where B. tabaci gather. The abundant natural enemy resources of B. tabaci in the open tomato fields should be protected. Meantime, in the early occurrence stage of B. tabaci in the greenhouse, the dominant natural enemies can be released to establish a natural enemy population, which can reduce the population density of B. tabaci in the greenhouse.

Key words: Bemisia tabaci, natural enemies, spatial distribution, temporal niche, ratios of natural enemies to pests

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