title: Identifying 1st instar larvae for three forensically important blowfly species using "fingerprint" cuticular hydrocarbon analysis.
abstract: Calliphoridae are known to be the most forensically important insects when it comes to establishing the minimum post mortem interval (PMImin) in criminal investigations. The first step in calculating the PMImin is to identify the larvae present to species level. Accurate identification which is conventionally carried out by morphological analysis is crucial because different insects have different life stage timings. Rapid identification in the immature larvae stages would drastically cut time in criminal investigations as it would eliminate the need to rear larvae to adult flies to determine the species. Cuticular hydrocarbon analysis on 1st instar larvae has been applied to three forensically important blowflies; Lucilia sericata, Calliphora vicina and Calliphora vomitoria, using gas chromatography-mass spectrometry (GC-MS) and principal component analysis (PCA). The results show that each species holds a distinct "fingerprint" hydrocarbon profile, allowing for accurate identification to be established in 1-day old larvae, when it can be challenging to apply morphological criteria. Consequently, this GC-MS based technique could accelerate and strengthen the identification process, not only for forensically important species, but also for other entomological samples which are hard to identify using morphological features.
authors.affiliation: Department of Chemical Ecology, School of Physical and Geographical Science, Keele University, Keele ST5 5BG, UK.
authors.forename: Hannah E
authors.initials: HE
authors.lastname: Moore
authors.affiliation: School of Physical and Geographical Science, Keele University, Keele ST5 5BG, UK.
authors.forename: Craig D
authors.initials: CD
authors.lastname: Adam
authors.affiliation: Department of Chemical Ecology, School of Physical and Geographical Science, Keele University, Keele ST5 5BG, UK. Electronic address: f.drijfhout@keele.ac.uk.
authors.forename: Falko P
authors.initials: FP
authors.lastname: Drijfhout
mesh_terms: D000818:Animals; D004175:Diptera / Q000502:physiology*; D005247:Feeding Behavior; D049429:Forensic Pathology; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D006838:Hydrocarbons / Q000032:analysis*; D034582:Integumentary System; D007814:Larva; D011180:Postmortem Changes; D025341:Principal Component Analysis
chemical_list: D006838:Hydrocarbons
keywords: Blowflies; Calliphoridae; Cuticular hydrocarbons; Forensic entomology; Gas chromatography–mass spectrometry; Principal component analysis