Influence of meteorological factors on the quantitative following relationship between Empoasca onukii Matsuda (Hemiptera: Cicadellidae) and its natural enemies in tea plantations

Abstract

Our aim was to study the close relationship between the number of Empoasca onukii and its natural enemies in tea plantations to provide a scientific basis for the control of E. onukii. The relationship between the number of E. onukii and its main natural enemies in tea plantations in Hefei, China, were compared by gray relational analysis, and then the relationships between seven meteorological factors and the populations of E. onukii were analyzed by the method of path analysis. The results showed that among the top six natural enemies most closely related to the population of E. onukii, two natural enemies were the same in the three years of study and four natural enemies were the same in any two years of the study, and that the natural enemy species closely related to the population of E. onukii varied greatly among years. The direct effect of monthly average relative humidity was the greatest effect in 2020 and the direct effect of monthly average temperature was the greatest effect in 2021, with both being negative in terms of their effect on the population size of E. onukii. The direct effect of the number of days of rainfall was the greatest effect in both 2021 and 2022, and the indirect effect of monthly sunshine hours through rainfall days was the greatest effect on the population of E. onukii. The highest temperatures in early and mid-August 2022 were higher than in previous years, which had an impact on the growth and development of subsequent E. onukii.

Evaluating the competition intensity of wandering spiders feeding on Empoasca onukii under varying cicada–spider ratios in tea plantations

“…As a predatory natural enemy, wandering spiders are active hunters, demonstrating a high level of predation on a broad range of prey over a wide home range, and therefore play an important role in the control of pests and provide balance to the ecosystem (Enders 1975). There have been many reports on the use of predatory natural enemies for the biological control of pests in tea plantations (Chen et al 2023a(Chen et al , 2023bCheng et al 2022;Qian et al 2019;Zhang et al 2021). Most of these studies have directly discussed natural enemy species with the greatest association with pests; however, by unifying the relationship between natural enemies and pest populations according to some criteria, the effect of the ratio of the number of individuals of E. onukii to the number of wandering spiders of different species (referred to as cicada-spider ratios in this article) on the competitive effects of wandering spiders has rarely been studied.…”