Wing Shape Analysis Of The Scorpionflies(Mecoptera: Panorpidae) Using Geometric Morphometrics

Colour polymorphism is a common phenomenon in many groups of insects. Thisphenomenon allows adaptation to different environments, and is also one of the main reasonsfor synonymy in insect taxonomy practices.The scorpionfly Panorpa liui Hua,1998is a widespread species in the northeasternregion of China, with a typical yellowish-brown body and ground colour of wings. However,a black-bodied Panorpa (melanic morph) and a black-tailed Panorpa (intermediate morph)are frequently encountered sympatrically with the typical brown morph of P. liui, to whichthey are very similar in appearance.Geometric morphometric analyses were conducted on the variation of the right forewingshape with P. changbaishana, P. liui and P. jilinensis as reference species. The results showthat the wing shapes of the intermediate and melanic morphs are very similar to and difficultto separate from that of the typical morph of P. liui based on the canonical variance analysis,between-group PCA (principal component analysis) and the PCA. The partial Procrustesdistance between the melanic morph and the typical P. liui is the smallest, indicating that theyare the most similar on wing shape. The melanic morph and the intermediate morph are nearlythe same on wing size, and larger than the typical morph of P. liui.Differences in wing morphology are described for these three morphs and indicate thatgeometric morphometric analyses of wing characters accurately classify individuals of theunknown specimens and can reliably discriminate between colour polymorphism groups inspecific level. The reason of colour polymorphism and its possibility of causing synonyms intaxonomy are briefly discussed.