Wing morphometrics as a tool in species identification of forensically important blow flies of Thailand

Abstract

BackgroundCorrect species identification of blow flies is a crucial step for understanding their biology, which can be used not only for designing fly control programs, but also to determine the minimum time since death. Identification techniques are usually based on morphological and molecular characters. However, the use of classical morphology requires experienced entomologists for correct identification; while molecular techniques rely on a sound laboratory expertise and remain ambiguous for certain taxa. Landmark-based geometric morphometric analysis of insect wings has been extensively applied in species identification. However, few wing morphometric analyses of blow fly species have been published.MethodsWe applied a landmark-based geometric morphometric analysis of wings for species identification of 12 medically and forensically important blow fly species of Thailand. Nineteen landmarks of each right wing of 372 specimens were digitised. Variation in wing size and wing shape was analysed and evaluated for allometric effects. The latter confirmed the influence of size on the shape differences between species and sexes. Wing shape variation among genera and species were analysed using canonical variates analysis followed by a cross-validation test.ResultsWing size was not suitable for species discrimination, whereas wing shape can be a useful tool to separate taxa on both, genus and species level depending on the analysed taxa. It appeared to be highly reliable, especially for classifying Chrysomya species, but less robust for a species discrimination in the genera Lucilia and Hemipyrellia. Allometry did not affect species separation but had an impact on sexual shape dimorphism.ConclusionsA landmark-based geometric morphometric analysis of wings is a useful additional method for species discrimination. It is a simple, reliable and inexpensive method, but it can be time-consuming locating the landmarks for a large scale study and requires non-damaged wings for analysis.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-017-2163-z) contains supplementary material, which is available to authorized users.

Exaggerated male forelegs are not more differentiated than wing morphology in two widespread sister species of black scavenger flies

“…Wing shape often varies among populations and species and can even be used for taxonomic inference (Sontigun et al, ). However, compared to size, shape differentiation among populations and closely related species is usually weak and often attributed to (stabilizing) natural selection (Gilchrist et al, ; Gilchrist & Partridge, ).…”

“…Wing shape often varies among populations and species and can even be used for taxonomic inference (Sontigun et al, 2017).…”

Using the modern morphometric approach to determine sexual dimorphism of three medically important flies (Order: Diptera) in Thailand

“…Previous research has explored a checklist of medically important flies in the central region of Thailand and found that they have dense populations, especially Chrysomya megacephala (Fabricius) and Musca domestica (Linnaeus) . Correct species identification of flies is a crucial step for understanding their biology, which relates to formulating successful control vectors (Sontigun et al 2017). Species identification of flies is quite challenging because many species have similar morphologies that easily cause identification errors.…”

“…For example, organs or other body parts necessary for identifying a species or sex are damaged. Recently, the modern technique has been used to successfully identify 12 species of forensically important blowflies (Sontigun et al 2017) and 12 species of flesh flies in Thailand (Sontigun et al 2019).…”

Geometric morphometrics as a tool for three species identification of the firefly (Coleoptera: Lampyridae) in Thailand

“…The advantage of GM is that it is a cheap method which does not require much equipment, is easy to use and is rapid (Rohlf 2002). Currently, both GM methods have been applied to the study of entomology, including mosquito (Chaiphongpachara 2018;, beetle (Lamb et al 2013), blow-fly (Sontigun et al 2017), spider (Fernández and Marugán 2017), pupae of flies (Chaiphongpachara and Laojun 2019), and bee (De Souza et al 2015). Although it is an effective alternative tool, not all organisms can be identified by this technique, so it is necessary to study the feasibility of applying it to each organism (Ruangsittichai et al 2011).…”