Effects of Skunk vine (Rubiaceae) on Spider mite (Acari: Tetranychidae) occurrence at Peach Orchards as an insectary plant of phytoseiid mites (Acari: Phytoseiidae)

Earlier studies have demonstrated that Paederia foetida L. (skunk vine) harbors larger numbers of phytoseiid mites for longer periods than any other wild plant in peach orchards. To assess the effectiveness of P. foetida in spider mite control, first, longevity and fecundity of Tetranychus kanzawai Kishida were examined in the laboratory using P. foetida and Phaseolus vulgaris L. as host plants. Results showed that all T. kanzawai larvae died without molting and that female adults laid few eggs on P. foetida. No such adverse effect on larvae or female adults was observed on P. vulgaris. Then, population surveys of spider mites and phytoseiid mites were conducted on peach trees with and without P. foetida. Results showed that the presence of P. foetida itself was inadequate to achieve decreased spider mite populations on peach leaves under any circumstances.