A Morphological and Genetic Analysis of Forensically Important Blow Flies, from Georgia: The Genus Lucilia

Publication Year:
2014
Usage 1172
Downloads 1039
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Repository URL:
https://digitalcommons.georgiasouthern.edu/honors-theses/3
Author(s):
Googe, Katie S
Tags:
Morphology; COI; Blowflies; Lucilia; Georgia; Forensics; Biology; Entomology; Molecular Genetics; Population Biology; Student Research & Creative Works, University Honors Program, Theses
thesis / dissertation description
Identification of Blow flies (Diptera: Calliphoridae) to species is important for estimating postmortem intervals, because insect species develop at different rates. Three Blow fly species in Georgia; Lucilia coeruleiviridis, L. cuprina, and L. sericata are similar morphologically, making identification difficult. Furthermore, the status of L. cuprina is in doubt; this species may be a complex of true L. cuprina, and L. cuprina x L. sericata hybrids. The objective of this study was to survey the Georgia Blow fly community and validate the statuses of L. coeruleiviridis, L. cuprina, and L. sericata, through morphological and genetic analyses. For a representative sample, stillborn pigs were placed at five field sites in South Georgia and flies collected from each location over a 72 hour time period. Morphological identifications, to species, were performed using dichotomous keys. We found L. coeruleiviridis at all five locations, L. cuprina at two locations, and zero L. sericata. Lucilia cuprina traits were more variable than previously reported. We sequenced the COI gene for 31 Lucilia flies; 29 COI sequences confirmed morphological identifications, while 2 COI sequences did not match the morphological identifications. There were extremely low sequence differences in both L. coeruleiviridis and L. cuprina. Thus, this study concluded that although bristles, the key feature used to identify a species, are more variable than believed, morphological and genetic analyses correspond well. To ensure a high level of accuracy, however, we suggest that both morphological and genetic techniques be used to identify Lucilia species in Georgia.