Establishing the presence of vine thrips in vineyards of Sveti Ivan Zelina

The vine thrips feed on vegetative and generative organs of the grapevine and cause damage in production. At the beginning of vegetation it sucks on the grapevine shoots and so they lag behind in growth. Later, it feeds on the leaves, and spotted necrosis is observed at the sucking sites. Later light yellow leaf coloration can be seen. Attack signs can also be noticed on the berries and since there is usually aesthetic damage table grape varieties suffer the most. Although the pest has been present in Croatia since the 1980s, little is known about the flight dynamics and the population size of this species. This study investigated the catch dynamics and population size of vine thrips in two vineyards (Gradunje and Vrškojice) in the area of Sveti Ivan Zelina. The thrips population was monitored during the vegetation season of 2018 by fluorescent yellow sticky traps (Csalomon®). In both vineyards pest presence was established at the beginning of May, and the last catches were recorded in the second half of September. According to the catch dynamics, the pest develops three generations in the investigated vineyards, and the highest number of thrips was recorded in the phase of growth and development of berries. Given the established thrips populations, its control is recommended, and in Croatia for this purpose only insecticide based on the active substance spinetoram has been registered.