Comparative Wing Morphometrics of Some Calyptrate Diptera

Abstract

Canonical variate analysis and the generalized distance Dz statistic are useful ways of analyzing within and between variation in species. Little attempt has been made previously to quantify and assess the variation in calyptrate Diptera other than in descriptive terms. In this study, the variation was assessed for 11 species of muscoid Diptera and populations of the five calliphorid species were analyzed in greater detail. Nine morphometric characters of the wing were used. Most of the variance (937:) fell in the first three canonical variates for the species comparison. and emphasised shape atrributes. although size was important. In particular. the position of vein R , . humeral vein 11. and the discal cell suggested that the sarcophagid flies formed an intermediate group between the calliphorid and muscid flies examined. Size components were more important than shape components within species. and these differences between populations could not be related to a geographic cline. IntroductionIn this study, the similarities between several species of muscoid flies are examined with respect to wing characters. The examination of character variation within a single functional "organ" system can provide much information in closely related taxa. It could be argued that the wing reflects much of the evolutionary history of the group, the shape being relatively stable unlike size which can be influenced by nongenetic factors. It is from studying patterns of character variation in populations, including geographic variation, that an insight into relationships between those populations may be gained. Many workers have previously assessed single character variation over geographic range by univariate methods, but increasingly, groups of characters are being assessed simultaneously using multivariate techniques (Sokal 1965;Gould and Johnston 1972;Thorpe 1976). Shape factors especially, because they reflect more complex interaction, can only be adequately assessed by using multivariate methods that simultaneously consider the variation of many characters (Atchley 1971 ; Atchley and Hensleigh 1974). Further, as adaptations of populations are multidimensional, variation within and between taxa may be better resolved by using such multivariate methods as canonical variate analysis (= multiple discriminate function analysis). This type of intra-specific variation analysis is carried out with diverse aims, for it can be used to describe variation patterns of a species, or to subdivide a variable species into subspecific units, thereby gaining an insight into the evolutionary forces acting upon a species (Sokal 1965). The multivariate analysis allows for the efficient summarization of large data sets so that populations or species may be compared or contrasted using fewer metrics. Effectively data sets representing the morphology of taxa can be expressed as a single data point in multivariate hyperspace. Biological interpretation is made from the relative positions and distances between these data points.In wings of di...

Wing morphometrics for identification of forensically important blowflies (Diptera: Calliphoridae) in Iberian Peninsula

“…Brown was one of the first researchers to perform GM studies on Diptera wings, although he also used other distance measurements between wing characters, separating taxa according to wing size and shape [68]. In this study, the separation of taxa into family groups was basically due to shape, rather than to size components, and for each of the calliphorid species, there appeared to be no pattern to the variability between populations, unlike the head/frons ratio used to establish the latitudinal cline in other species of Muscoidea.…”

Geographic variation of wing morphology in three Eurasian populations of the fruit fly, Drosophila lummei

“…Morphometric analysis of insect wings has been used to distinguish the relationship between closely related taxa (Brown & Shipp, 1977, 1978Brown, 1979;Rohlf & Archie, 1984;Byers, 1989;Yu et al, 1992;Kukalova-Peck & Peck, 1993;Ansorge, 1994;Diniz-Filho & Malaspina, 1995). Further, morphometric wing analysis can differentiate among populations within a species.…”

Identification of Muscidae (Diptera) of medico-legal importance by means of wing measurements

“…This confirms earlier studies concerning other insects (Gaston and O’Neill 2004 ). In Diptera, the wing measurements were used successfully for the quantification of both within and between species variations (Brown 1980 ; Klingenberg et al 1998 ; Alves and Bélo 2002 ; Hall et al 2014 ; Siomava et al 2016 ). The wing venation differs markedly between Diptera species, and it can be used for identification of mosquitoes (Dujardin 2011 ; Sumruayphol et al 2016 ), tephritid flies (Van Cann et al 2015 ), tsetse flies (Kaba et al 2016 ), screwworm flies (Lyra et al 2010 ), and stable flies (Changbunjong et al 2016 ).…”