Composition, seasonal abundance and within-plant distribution of Thysanoptera species associated with seedless grapes (Sultana) in districts of Manisa, Turkey

This study investigated the species composition of Thysanoptera and the within-plant distribution, abundance and relation to plant phenology of major species on Round Seedless grapes (Vitis vinifera L. var. Sultana) in the Manisa Province, Turkey in 2003-2005. Monthly surveys were conducted in 41 vineyards in 11 districts of the province starting with bud burst (early April) and ending with complete defoliation (late November). Thrips were collected by beating plants in the field or by examining plant samples in the laboratory. A total of 35 Thysanoptera species was recorded. The most common and abundant species were (in descending order): Rubiothrips vitis (Priesner, 1933), Thrips tabaci (Lindeman, 1889), Mycterothrips albidicornis (Knechtel, 1923) + M. tschirkunae (Jachontov, 1961), Frankliniella occidentalis (Pergande, 1895) and Drepanothrips reuteri Uzel, 1895 (Thripidae). All major species were present in varying numbers from shoot growth to post-harvest. The highest thrips densities were attained during bud burst and early shoot growth, when R. vitis was the only species detected. Thereafter, R. vitis number declined sharply. Other major species, with the exception of T. tabaci, tended to increase before fruit ripening and/or afterwards. The most abundant species on different parts of the grapevines were as follows: T. tabaci, D. reuteri and R. vitis on leaves and shoots; T. tabaci, D. reuteri and F. occidentalis in flowers and D. reuteri in bunches. R. vitis has the highest potential to pose a threat to seedless grapes. The abundance of F. occidentalis is low; therefore, the incidence of scars or spots on berries attributed to it and quarantine problems stemming from its presence in exported table grapes are expected to be minimal.