Application of COI gene for identification of some economically and forensically important muscid flies of India (Diptera: Muscidae)

Muscid flies are of great medical and veterinary importance because of their ability to transmit diseases to humans and animals. Their larvae are found on dead bodies and are used as a forensic indicator for estimating Post-Mortem Interval (PMI). A drawback of morphological identification of these larvae is lack of an identification key which covers all the life stages of the taxa. To overcome the problem, entomologists now focus on the alternative methods, which can speed up the identification process. Barcoding region of Cytochrome oxidase I (COI)l is believed to be the best among other markers for precise identification and to mark out phylogeny. During the present study, total 63 specimens of 24 species belonging to 7 genera representing the various muscid subfamilies were used to check the efficacy of COI gene in identification. 11 species were collected from various regions (Punjab, Haryana, Himachal Pradesh, Uttarakhand) of North India during the years 2015-2019, and sequences of rest of the species were downloaded from the database of Genbank. The percentage of intraspecific divergences ranged from 0%-0.5% for species of India and 0%-3.0% for the sequences from other countries. The interspecific divergence ranged from 3.1% to 17.3% and 3.3% to 16.7% respectively for Indian species and species from the other part of the world. 1000 bootstrapped Neighbor-joining with Kimura-2 parameter phylogenetic tree constructed based on COI gene sequences, clearly separated 24 species of these Muscid flies. This is the first ever study on COI gene based identification of medico-legal, veterinary and forensically important Muscid flies from India.