Temporal and spatial distributions of phytoseiid mites on citrus, Ageratum conyzoides and Praxelis clematidea
Author of the article:FANG Xiao-Duan； LU Hui-Lin；SONG Zi-Wei；OUYANG Ge-Cheng
Author's Workplace：Guangdong Key Laboratory of Animal Conservation and Resource Utilization, Guangdong Public Laboratory of Wild Animal Conservation and Utilization, Guangdong Institute of Applied Biological Resources, Guangzhou, 510260, China; Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Plant Protection Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, China)
Key Words： phytoseiid mite; Ageatum conyzoides; Praxelis clematidea; spatial and temporal distribution; citrus orchard
Abstract：[Objectives] To determine the temporal and spatial distribution of phytoseiid mites, important predators of citrus pests in citrus orchards, and particularly the relative importance of the weeds A. conyzoides and P. clematidea as habitat for these mites. The weed, Praxelis clematidea, is frequently confused with Ageatum conyzoides and consequently protected, or even planted. However, it is unclear if the ecological role of P. clematidea is similar to that of A. conyzoides in citrus orchards, especially with respect to providing habitat for predatory mites. [Methods] The regular leaf-picking method was used to investigate the temporal and spatial distributions of phytoseiid mites and Panonychus citri on citrus, and the whole-plant sampling method to survey phytoseiid mites on A. conyzoides and P. clematidea. [Results] The density of phytoseiid mites was highest at 23:30 on the periphery of the crown of citrus trees, whereas that of P. citri was highest at 15:30. During the day, phytoseiid mites were clearly more abundant on A. conyzoides than on P. clematidea, however at night there was no significant difference in phytoseiid mite abundance between these two plants. Phytoseiid mites preferred to inhabit at A. conyzoides during the daytime but left these plants at night. [Conclusion] Conserving A. conyzoides in citrus orchards and spraying citrus trees during the day when the density of phytoseiid mite on the trees is relatively low and that of P. citri is highest on the periphery of the crown, could help to both control P. citri and protect phytoseiid mites.Key words phytoseiid mite; Ageatum conyzoides; Praxelis clematidea; spatial and tem