Geometric morphometric wing analysis represents a robust tool to identify female mosquitoes (Diptera: Culicidae) in Germany

F G Sauer,J Schmidt-Chanasit,E Kiel,R Lühken,A Heitmann,L Jaworski,L Erdbeer

doi:10.1038/s41598-020-72873-z

Abstract

Accurate species identification is the prerequisite to assess the relevance of mosquito specimens, but is often hindered by missing or damaged morphological features. The present study analyses the applicability of wing geometric morphometrics as a low-cost and practical alternative to identify native mosquitoes in Germany. Wing pictures were collected for 502 female mosquitoes of five genera and 19 species from 80 sampling sites. The reliable species identification based on interspecific wing geometry of 18 landmarks per specimen was tested. Leave-one-out cross validation revealed an overall accuracy of 99% for the genus and 90% for the species identification. Misidentifications were mainly due to three pairings of Aedes species: Aedes annulipes vs. Aedes cantans, Aedes cinereus vs. Aedes rossicus and Aedes communis vs. Aedes punctor. Cytochrome oxidase subunit I (COI) gene region was sequenced to validate the morphological and morphometric identification. Similar to the results of the morphometric analysis, the same problematic three Aedes-pairs clustered, but most other species could be well separated. Overall, our study underpins that morphometric wing analysis is a robust tool for reliable mosquito identification, which reach the accuracy of COI barcoding.

Highlights

Mosquitoes (Diptera: Culicidae) are a widespread taxonomic group, which occurs from tropical to subarctic regions
We provided an overview of centroid size variation of the common mosquito species in Germany
The centroid size is more sensitive to detect sample variation compared to one-dimensional measurements, e.g. wing length[49]. It is an adequate indicator for the wing and body s ize[38] and supply useful background information for the discrimination of certain species pairs as we could show in a pairwise comparison of the centroid size per mosquito species

Summary

Introduction

Mosquitoes (Diptera: Culicidae) are a widespread taxonomic group, which occurs from tropical to subarctic regions. Thereby, the identification requires considerable knowledge about the variation of the different taxonomic characters. Geometric morphometrics is a promising alternative technique to identify insect species using anatomical landmarks[15]. Landmark collections are a cost-effective technique, which requires very little entomological experience compared to standard morphological identification. It was shown before that the analyses of landmark configurations can be used to reliably identify mosquito species[18,19,20], even if morphological identification with standard taxonomic keys is not possible e.g., female Culex pipiens pipiens form pipiens Linnaeus vs Culex torrentium Martini[21]. To the authors’ knowledge, only three studies applied morphometric wing analysis to native mosquito species in Europe. Intraspecific variations of mosquito wings were analysed for European population of Aedes vexans (Meigen)[22] and Cx. pipiens s.l.23. Börstler et al.[21] used morphometric diagnosis to discriminate female Cx. pipiens s.s. and Cx. torrentium

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Conclusion