Diversity of thrips species (Thysanoptera) in fruit orchards in Qazvin province, northwestern Iran

This study was done during 2012 to 2014 to determine the species composition of thrips on fruit trees and weeds of orchards in three counties of Qazvin Province (i.e. Buin-Zahra, Takestan and Qazvin). For each county 14 orchards were sampled. In each orchard, 10 trees and from each tree four shoots along with their leaves, flowers and fruits were selected as a sample unit. Diversity was calculated by Shannon-Wiener Index and evenness by Pielou evenness index. Species richness was estimated using the first-order jackknife richness estimator. One-way ANOVA was used to test whether there exists significant variation in species diversity, evenness and richness along the three counties. Of the 4,489 adult collected specimens from three locations, 27 species belonging to 13 genera were identified. The highest number of thrips was collected on plants of family Rosaceae, followed by Vitaceae and Moraceae, respectively. The number of collected species in Qazvin (18) and Buin-Zahra (17) counties were more than Takestan (13) county. Similar trend was observed for the total number of adult specimens collected in the three counties as more specimens were found in Qazvin and Buin-Zahra than Takestan. Results of this study showed that Thrips tabaci L. was found on all species of fruit trees and weeds. There were no significant differences among the three counties in terms of both diversity (P = 0.41) and evenness (P = 0.45). Across the counties, thrips estimated richness was higher in Qazvin county compared to Buin-Zahra and Takestan counties. Among the trees in Buin-Zahra and Takestan counties, grape had the highest thrips diversity. The highest value of diversity for Qazvin county was recorded for apricot. The polyphagous species T. tabaci was dominant in all three counties, followed by Frankliniella occidentalis (Pergande) (in Qazvin county), Frankliniella intonsa (Trybom) (in Buin-Zahra county) and Frankliniella tenuicornis (Uzel) (in Takestan county).