Mitochondrial COX1 gene based delineation of putative insect species from Salt Lake of Great Rann of Kutch, India

Abstract

Insect biodiversity of Salt Lake of Great Rann of Kutch in western India has not been studied in detail so far. This region is one of its kinds being a seasonal salt marsh representing India and Pakistan. Shore insects are one of the major invertebrates that inhabit this unique habitat and use carbon source for their growth and are considered as greenhouse pests. To identify these less described insect taxa, first specimens were morphologically delineated the species. Thereafter, DNA barcoding based on COX1 gene was applied to distinguish specimens collected into 9 different species. The quantification of biodiversity revealed that 80% of specimens belonged to Diptera and 10% each of Hymenoptera and Coleoptera. Based on molecular identification, two specimens that had 99% similarity with GenBank sequences were identified up to species level and were designated as Australospesis niveipennis (Diptera: Sepsidae) (insect code as SH6 GenBank accession no. KP227753 and SH7 accession no. KP227754) and one species designated as Atherigona varia (Diptera: Muscidae) (insect code SH2 GenBank accession no. KP227750). Three species were in dentified up to genus level, viz., Musca sp. (Diptera: Muscidae) (insect code SH1 GenBank accession no. KP227749), Microchironomus sp. (Diptera: Chironomidae) (insect code SH4 GenBank accession no. 227752) and Lispe sp. (Diptera: Muscidae) (insect code SH12 GenBank accession no. KP227758). However, other four insects could be identified up to family level only as it has similarity from 77-91% only in GenBank similarity test. These insects belonged to Chloropidae, Staphylinidae and Evaniidae. A monophyletic tree was observed with 4 clades showing interordinal relationship between 7 species of Order Diptera, 1 species of Coleoptera and 1 species of Hymenoptera. The overall transition/transversion bias R was 3.70 and nucleotide composite distance was 0.232, indicating a strong negative correlation trend, which suggests further sampling of these taxa in the Salt Lake area in different seasons.