Use of PCR-RFLP for differentiation of calliphorid larvae (Diptera, Calliphoridae) on human corpses

Blowfly larvae found on human corpses are important for the estimation of the postmortem interval (PMI) and other questions of forensic relevance. Some of these species are difficult to differentiate morphologically, therefore a molecular method was elaborated for species identification. Specific fragments of the COI and COII region of the mitochondrial DNA (mtDNA) were amplified followed by digestion with different restriction enzymes. Using a 1.3 kb fragment, identification of Lucilia sericata, Calliphora vicina and Calliphora vomitoria was possible by digestion with only one restriction enzyme using either DraI or HinfI. Furthermore, we sequenced 349 bp (a part of the COI and COII regions) from the same three species and found 34 nucleotide distinctions between C. vicina and L. sericata, 30 between C. vomitoria and L. sericata and 15 between the two Calliphora species. These results aid in quick identification of species used for estimation of PMI.