Diversity and community structure of Odonata (Insecta) in two land use types in Purba Medinipur District, West Bengal, India

摘要

The present study recorded a total of 45 species of Odonata, of which one species, Ischnura mildredae , was recorded for the first time from West Bengal in India. Thirty-eight species were found in Tamluk Municipality as compared to 21 species in Haldia Industrial Belt (IB), with 14 species common to both the localities. Index of similarity revealed that the two localities were slightly dissimilar in odonate faunal composition as only 47% of species were shared. In both the localities, Anisoptera was more abundant, comprising over 69% of the total odonates. Libellulidae was the most abundant Anisopteran family in both the localities, comprising over 66% of the total odonates. Coenagrionidae was the most abundant Zygopteran family in both the localities. Thirteen species of Anisoptera and 11 species of Zygoptera were found only in Tamluk whereas two species of Anisoptera and five species of Zygoptera were found only in Haldia IB. Crocothemis servilia , Pantala flavescens , and Ceriagrion coromandelianum were the dominant species in Tamluk while Brachythemis contaminata and Orthetrum sabina were the dominant species in Haldia IB. Based on the values of Shannon index, Tamluk was considered unpolluted (=3.16) and Haldia IB moderately polluted (=2.43). Higher equitability index (J=0.87) and very low dominance index (0.06) in Tamluk indicated homogeneity in community composition and relatively stress-free equitable environment. The present investigation suggests that Odonata can be used as bioindicators of industrial pollution.