Molecular phylogeny of the forensically important genus Cochliomyia (Diptera: Calliphoridae)

Sohath Yusseff-Vanegas,Ingi Agnarsson

doi:10.3897/zookeys.609.8638

Abstract

Cochliomyia Townsend includes several abundant and one of the most broadly distributed, blow flies in the Americas, and is of significant economic and forensic importance. For decades, Cochliomyia hominivorax (Coquerel) and Cochliomyia macellaria (Fabricius) have received attention as livestock parasites and primary indicator species in forensic entomology. However, Cochliomyia minima Shannon and Cochliomyia aldrichi Del Ponte have only been subject to basic taxonomy and faunistic studies. Here we present the first complete phylogeny of Cochliomyia including numerous specimens per species, collected from 13 localities in the Caribbean. Four genes, the mitochondrial COI and the nuclear EF-1α, 28S rRNA, and ITS2, were analyzed. While we found some differences among gene trees, a concatenated gene matrix recovered a robustly supported monophyletic Cochliomyia with Compsomyiops Townsend as its sister group and recovered the monophyly of Cochliomyia hominivorax, Cochliomyia macellaria and Cochliomyia minima. Our results support a close relationship between Cochliomyia minima and Cochliomyia aldrichi. However, we found Cochliomyia aldrichi containing Cochliomyia minima, indicating recent speciation, or issues with the taxonomy of the group. We provide basic information on habitat preference, distribution and feeding habits of Cochliomyia minima and Cochliomyia aldrichi that will be useful for future forensic studies in the Caribbean.

Highlights

Cochliomyia Townsend is endemic to the Americas and includes only four species: Cochliomyia minima Shannon, C. aldrichi Del Ponte, C. macellaria (Fabricius) and C. hominivorax (Coquerel)
Cochliomyia macellaria, C. hominivorax and C. minima were recovered as monophyletic, while C. aldrichi was recovered as paraphyletic
Independent analyses of 28S and internal transcribed spacer 2 (ITS2) supported the monophyly of Cochliomyia, while cytochrome oxidase I (COI) and EF-1α recovered it as a paraphyletic group (Suppl. material 1)

Summary

Introduction

Cochliomyia Townsend is endemic to the Americas and includes only four species: Cochliomyia minima Shannon, C. aldrichi Del Ponte, C. macellaria (Fabricius) and C. hominivorax (Coquerel). Cochliomyia hominivorax is an obligate parasite with its larvae producing myiasis and feeding on living tissue (Hall 1948, Guimaraes et al 1983) This species is one of the most important insect pests of livestock in the Neotropics causing economic losses of billions of dollars every year (Vargas-Terán et al 2005). It is worth noting that in 1988 this species was introduced in Libya and it was successfully eradicated in 1992 based on the sterile insect technique (SIT) This was the major international effort and avoid a major disaster for the livestock industry of Africa and Southern Europe (Lindquist et al 1992). Despite those successfully eradications C. hominivorax continues to be an economically important pest in South America and parts of the Caribbean (Vargas-Terán et al 2005)

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