Wing measurements are a possible tool for the identification of European forensically important Sarcophagidae

An illustrated identification key to early instar larvae of forensically important Muscidae (Diptera) of the western Palaearctic region

There is a significant gap in the availability of comprehensive identification keys for the early larval stages of forensically important fly species. While well-documented identification keys exist for the third instar larvae, particularly for the Calliphoridae, Muscidae and Sarcophagidae families, there is a notable scarcity of keys for the first, except Calliphoridae, and the second instar larvae, with no such resources available for muscid species. The second instar larvae suffer the most from the lack of morphological descriptions and available identification keys. The Muscidae is one of the most frequently reported dipteran families of forensic importance colonising animal cadavers and human corpses. Nevertheless, descriptions of the morphology of their early instars remain scarce and limited to only a few species, thus their larval identification is challenging or impossible. Considering the numerous challenges associated with studying small-sized entomological material, we tested whether it is feasible to identify muscid flies to the species or at least genus level based predominantly on the details of the cephaloskeleton. To overcome the obstacle of observing details of small sclerites, especially their shapes and interconnections, we effectively employed confocal laser scanning microscopy (CLSM) as a supplementary method for light microscopy (LM). This study provides an identification key for first and second instar larvae of forensically important muscid species from the western Palaearctic (Europe, North Africa, Middle East). The proposed key primarily utilises details of the cephaloskeleton with only addition of external morphology.

Geometry of posterior larval spiracles to identify medically and forensically important calliphorids in Thailand

Fly identification is the primary step of analysis in forensic entomology. Although morphology and molecular techniques are considered satisfactory methods, some constraints may arise from a financial or even human point of view. Over the past decade, the geometric morphometric approach has been increasingly advocated for the classification and identification of arthropods. This study explored the method for species identification of 800 third-instar larvae of eight blow fly species of medical and forensic importance: Chrysomya chani Kurahashi, Chrysomya megacephala (Fabricius), Chrysomya (Ceylonomyia) nigripes Aubertin, Chrysomya pinguis (Walker), Chrysomya (Achoetandrus) rufifacies (Macquart), Hemipyrellia ligurriens (Wiedemann), Lucilia cuprina (Wiedemann), and Lucilia porphyrina (Walker). Based on the posterior spiracles geometry, the cross-validation revealed a relatively high percentage of correct classification in most species, ranking from 86% to 100%. The results of this study confirmed that the geometric morphometric (GM) analysis of posterior spiracles might be utilized as a larva identification tool. Therefore, this GM method represents one way of overcoming difficulties with the identification of blow fly larvae and can support further studies of these flies.

Honey bee (Apis mellifera) wing images: a tool for identification and conservation

BACKGROUND

The honey bee (Apis mellifera) is an ecologically and economically important species that provides pollination services to natural and agricultural systems. The biodiversity of the honey bee in parts of its native range is endangered by migratory beekeeping and commercial breeding. In consequence, some honey bee populations that are well adapted to the local environment are threatened with extinction. A crucial step for the protection of honey bee biodiversity is reliable differentiation between native and nonnative bees. One of the methods that can be used for this is the geometric morphometrics of wings. This method is fast, is low cost, and does not require expensive equipment. Therefore, it can be easily used by both scientists and beekeepers. However, wing geometric morphometrics is challenging due to the lack of reference data that can be reliably used for comparisons between different geographic regions.

FINDINGS

Here, we provide an unprecedented collection of 26,481 honey bee wing images representing 1,725 samples from 13 European countries. The wing images are accompanied by the coordinates of 19 landmarks and the geographic coordinates of the sampling locations. We present an R script that describes the workflow for analyzing the data and identifying an unknown sample. We compared the data with available reference samples for lineage and found general agreement with them.

CONCLUSIONS

The extensive collection of wing images available on the Zenodo website can be used to identify the geographic origin of unknown samples and therefore assist in the monitoring and conservation of honey bee biodiversity in Europe.