Diversity and Richness of Spider Mites on Cucumber and Associated Predatory Mites in the Shivamogga and Davangere Districts of Karnataka, India

Abstract

A survey and surveillance study of spider mites on cucumber grown under protected and open-field conditions was conducted from June 2019 to May 2020 in major cucumber-growing areas of Shivamogga and Davangere districts. Two tetranychid mite species were recorded. Tetranychus macfarlanei (Baker & Pritchard, 1960) was the most abundant species in Shivamogga district, whereas Tetranychus urticae (Koch, 1836) was recorded in Davangere district. T. urticae is reported for the first time on cucumber in Davangere district. Among the natural enemies, the predatory phytoseiid mite Neoseiulus longispinosus (Evans, 1952) was encountered at all cucumber-growing locations, whereas the predatory coccinellid Stethorus punctillum punctillum (Weise, 1891) was recorded at some locations. These two natural enemies of spider mites are reported for the first time on cucumber from Shivamogga and Davangere districts. The generalist predatory beetle Cheilomenes sexmaculata (Fabricius, 1781) was observed in Sominakoppa village and at ZAHRS, Navile, while the predatory thrips Scolothrips rhagebianus (Priesner, 1950) was recorded only at ZAHRS, Navile, Shivamogga. The study documented the diversity of phytophagous mite pests under protected and open-field conditions in both districts. The occurrence of locally available predatory mites indicates their potential for evaluation in biological-control programmes.