Forensic entomology: Molecular identification of blowfly species (Diptera: Calliphoridae) in Portugal

Insects, in particular Calliphoridae species have a very important role in decomposition process and are the earliest insects to infest a corpse. An accurate morphological identification is essential but very difficult or even sometimes impossible to do. So, molecular identification provides a rapid and reliable method that can be done in all development stages. The potential of mitochondrial cytochrome oxidase subunit I (COI) is very well established. But in some species this gene is not effective. In this work, we used the ribosomal internal transcribed spacer 2 (ITS2) to complement COI data, demonstrating ITS2 effectiveness in insects' identification. Blowflies of the family Calliphoridae ( Calliphora vicina, Calliphora vomitoria, Lucilia caesar and Lucilia sericata) were collected in Portugal. COI fragments permitted correct specimens identification using BLAST search for all blowflies, except for L. caesar because of the high similarity with Lucilia illustris. For these species, we used ITS2 sequences for species determination. This genetic marker analysis facilitated the differentiation of these two species. Our results indicate that it would be of great importance to increase the sequences collection to prevent incorrect identification and reinforce results validity. (C) 2011 Elsevier Ireland Ltd. All rights reserved.