Morphology and identification of first instar larvae of Australian blowflies of the genus Chrysomya of forensic importance.

Light microscopy photographs, line illustrations and scanning electron microscopy micrographs are provided for first instar larvae of six Australian species of Chrysomya. All species have confirmed or potential in forensic investigations given their carrion-breeding habits. Morphology of the first instar larvae of Ch. nigripes, Ch. rufifacies, Ch. saffranea and Ch. varipes is revised, while larvae of Ch. incisularis and Ch. latifrons are described for the first time. The following morphological structures are documented: pseudocephalon, antennal complex, maxillary palpus, facial mask, thoracic and abdominal spinulation, spiracular field, posterior spiracles and cephaloskeleton. New diagnostic features of the cephaloskeleton and the spinulation of the abdominal segments are described. Verification of earlier descriptions revealed major discrepancies between published data, especially in the case of Ch. nigripes. The present results allow clarification, correction and, especially, complementation of the existing information provided by numerous authors. Finally, an identification key for first instar larvae of Australian necrophagous Chrysomya is presented.