Population development and distribution of Frankliniellaoccidentalis (Pergande) (Thysanoptera: Thripidae) in selectedstrawbery greenhouses

Plant protection has an important place among problems related to strawberry cultivation. Red spider mites and thrips are the main pests observed on strawberries, and among these, the most important for Antalya province is Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). This study was performed in 2017 and determined the population change and in-greenhouse distribution of Frankliniella occidentalis with direct counts on flowers and blue traps in three strawberry greenhouses in Serik county in Antalya province. The research was completed in three different greenhouses, with 25 blue sticky traps in the 1st greenhouse with 4 da size and the 2nd greenhouse with 3.5 da size and 15 traps in the 3rd greenhouse with 2.5 da size. Traps were collected each week, with the numbers of thrips recorded. On dates when the traps were changed, the thrips found on plants were counted by examining ten flowers on three plants below or close to the blue sticky traps by eye or with a loupe with counts performed until the day of harvest. At the end of the study, the pest population reached a certain level from the start of flowering in November in the three greenhouses, and then fell in the middle of December. From the middle of December, the population began to increase and this increase continued until the strawberries were harvested. The number of pests per trap varied from 0.6 to 1904.2. When the whole production season is considered, the mean pest numbers per trap in the three greenhouses were 287.2, 72.3 and 271.27 thrips/trap. The number of pests per flowerhead varied from 0.0 to 2.5. When the whole production season is considered, the mean numbers of pests per flowerhead in the greenhouses were 0.26, 0.08 and 0.16 thrips/flowerhead. In light of the data obtained in the study, and considering the economic damage threshold value recommended by previous research results, it was concluded there is no need for chemical intervention against F. occidentalis in the region.