A Survey of Diversity and Frequency of Oak Thrips during Different Seasons in Eyvan County (Ilam Province)

Abstract

Abstract In order to investigate the diversity and frequency of thrips species on oak trees, weekly sampling was done during different seasons in Kalan region (Eyvan county), as a part of oak forests of Ilam province (western Iran), in 2018. In this relation, 10 oak trees and 20 leaves were selected from each tree. Thrips were collected by shaking the leaves on a white plastic tray. The species diversity indices were calculated using the number of species and their relative abundance. One-way analysis of variance (ANOVA) was used to determine the statistical differences between species diversity indices in different sampling months. Out of the 841 collected thrips specimens, 14 thrips species were identified, which belonged to six genera and four families. Amongst them, Thrips tabaci Lindeman was the Eudominant species accounting for 47.65% of the abundance. In addition, among the collected thrips, Aeolothrips gloriosus, A. intermedius, A. melaleucus, Haplothrips globiceps, H. longipes, and H. subtilissimus were predators, and the rest were phytophagous. The highest abundance for predatory species with 13.32% was related to A. intermedius. The population peak of thrips was observed in May. The results of this study also showed that there was a statistically significant difference between species diversity indices in different months of the year (P≤0.05). The highest and lowest biodiversity indices (i.e. Shannon-Wiener diversity, Pielou, Margalef, and Simpson’s evenness) were 3.55 and 0.92 (for June and December), 0.76 and 0.28 (for September and December), 2.84 and 1.26 (for June and December), and 0.77 and 0.28 (for June and December) respectively.

Keywords

• diversity
• thrips
• population fluctuations
• oak trees
• ilam