Morphological identification of first-instar larvae of European flesh flies of forensic importance.

Flesh flies (Sarcophagidae), along with blow flies, are among the first colonizers of vertebrate cadavers, including human corpses. Their early colonization and rapid development frequently result in the collection of flesh fly larvae as evidence during crime scene investigations or autopsies. Despite their regular occurrence and confirmed forensic importance, the species-level identification of sarcophagid larvae remains challenging. To address this, the morphology of the first-instar larva of three common and widespread European species with confirmed forensic relevance-Sarcophaga africa, S. caerulescens, S. melanura-was revised. Material was analysed using both light microscopy and scanning electron microscopy (SEM). Taxonomically important characters were identified in the pseudocephalon, the facial mask, mouthhooks and basal sclerite of the cephaloskeleton, and the distribution and shape of spines and papillae of the anal plate. The results are compared with previous descriptions, and an identification key is presented for the first-instar larvae of forensically relevant flesh fly species of central and northern Europe.