A molecular, morphological, and physiological comparison of English and German populations of Calliphora vicina (Diptera: Calliphoridae)

Abstract

The bluebottle blow fly Calliphora vicina is a common species distributed throughout Europe that can play an important role as forensic evidence in crime investigations. Developmental rates of C. vicina from distinct populations from Germany and England were compared under different temperature regimes to explore the use of growth data from different geographical regions for local case work. Wing morphometrics and molecular analysis between these populations were also studied as indicators for biological differences. One colony each of German and English C. vicina were cultured at the Institute of Legal Medicine in Frankfurt, Germany. Three different temperature regimes were applied, two constant (16°C & 25°C) and one variable (17–26°C, room temperature = RT). At seven time points (600, 850, 1200, 1450, 1800, 2050, and 2400 accumulated degree hours), larval lengths were measured; additionally, the durations of the post feeding stage and intrapuparial metamorphosis were recorded. For the morphometric and molecular study, 184 females and 133 males from each C. vicina population (Germany n = 3, England n = 4) were sampled. Right wings were measured based on 19 landmarks and analyzed using canonical variates analysis and discriminant function analysis. DNA was isolated from three legs per specimen (n = 61) using 5% chelex. A 784 bp long fragment of the mitochondrial cytochrome b gene was sequenced; sequences were aligned and phylogenetically analyzed. Similar larval growth rates of C. vicina were found from different geographic populations at different temperatures during the major part of development. Nevertheless, because minor differences were found a wider range of temperatures and sampling more time points should be analyzed to obtain more information relevant for forensic case work. Wing shape variation showed a difference between the German and English populations (P<0.0001). However, separation between the seven German and English populations at the smaller geographic scale remained ambiguous. Molecular phylogenetic analysis by maximum likelihood method could not unambiguously separate the different geographic populations at a national (Germany vs England) or local level.

Sexual dimorphism in the wing geometry of Musca domestica L. (Diptera: Muscidae) from Colombia

“…Particularmente, este estudio evidenció un mayor tamaño alar en hembras que en machos de M. domestica. Este hallazgo es consistente con lo reportado previamente con otras moscas necrófagas (Diptera: Calyptratae) de la familia Calliphoridae como Calliphora vicina Robineau-Desvoidy (Limsopatham et al, 2018), Lucilia cuprina (Wiedemann), Chrysomya megacephala (Fabricius) y Chrysomya albiceps (Wiedemann) (Nuñez-Rodríguez & domestica no encontró un efecto significativo de la temperatura en el tamaño alar en ninguno de los sexos en una colonia joven de laboratorio de especímenes colectados en Italia (Siomava et al, 2016), probablemente explicado por un bajo número de grupos experimentales y de temperaturas probadas. En contraste, algunos datos recientes han sugerido una respuesta adaptativa diferencial en respuesta a la temperatura de poblaciones europeas de M. domestica (Kjaersgaard et al, 2015).…”

Comparative Analysis of Molecular Identification and Wing Morphometrics of Forensically Important Blow Flies in China

“…The comparison results show that both molecular analysis and wing morphometrics can be used as important methods to distinguish species, but for certain species, wing morphometrics may give a wrong result. Meanwhile, molecular identi cation cannot distinguish geographical populations for some species [32]. Therefore, we recommend classical molecular identi cation for species identi cation to achieve better accuracy, and wing morphometrics can be used as a supplementary tool to identify geographical origin and sex.…”

“…It has been proved that wing morphometrics can be used for the identi cation of necrophagous Calliphoridae from Thailand [27] and Europe [28], and distinguish different genus and species of Calliphoridae, Cochliomyia [29], Lucilia [23,30] and Chrysomya [29,31]. In addition, geometric morphometric analysis can be used to distinguish variability between geographical populations [29,32], seasonal morphs [33] or sexes [26,34] among the same species, and recently it is used to identify Piophilidae (Diptera) for forensic purpose [35]. All of these shows that the analysis of wing morphometric is a very useful identi cation method.…”

The Forensic Entomology Case Report—A Global Perspective

“…In cases where no local datasets are available, the practitioner should include a statement indicating that local data were not available. It must be noted, however, that developmental patterns by geographic separation may not always differ, and, in some cases, are comparable irrespective of location [ 34 , 43 ]. Species specificity: Where available, datasets pertaining to the actual species identified should be used.…”