Wing Morphometrics of Aedes Mosquitoes from North-Eastern France

Background: In the context of the increasing circulation of arboviruses, a simple, fast and reliable identification method for mosquitoes is needed. Geometric morphometrics have proven useful for mosquito classification and have been used around the world on known vectors such as Aedes albopictus. Morphometrics applied on French indigenous mosquitoes would prove useful in the case of autochthonous outbreaks of arboviral diseases. Methods: We applied geometric morphometric analysis on six indigenous and invasive species of the Aedes genus in order to evaluate its efficiency for mosquito classification. Results: Six species of Aedes mosquitoes (Ae. albopictus, Ae. cantans, Ae. cinereus, Ae. sticticus, Ae. japonicus and Ae. rusticus) were successfully differentiated with Canonical Variate Analysis of the Procrustes dataset of superimposed coordinates of 18 wing landmarks. Conclusions: Geometric morphometrics are effective tools for the rapid, inexpensive and reliable classification of at least six species of the Aedes genus in France.

Diversification Pattern of the Widespread Holarctic Cuckoo Bumble Bee, Bombus flavidus (Hymenoptera: Apidae): The East Side Story

Recent bumble bee declines have made it increasingly important to resolve the status of contentious species for conservation purposes. Some of the taxa found to be threatened are the often rare socially parasitic bumble bees. Among these, the socially parasitic bumble bee, Bombus flavidus Eversmann, has uncertain species status. Although multiple separate species allied with B. flavidus have been suggested, until recently, recognition of two species, a Nearctic Bombus fernaldae (Franklin) and Palearctic B. flavidus, was favored. Limited genetic data, however, suggested that even these could be a single widespread species. We addressed the species status of this lineage using an integrative taxonomic approach, combining cytochrome oxidase I (COI) and nuclear sequencing, wing morphometrics, and secretions used for mate attraction, and explored patterns of color polymorphism that have previously confounded taxonomy in this lineage. Our results support the conspecificity of fernaldae and flavidus; however, we revealed a distinct population within this broader species confined to eastern North America. This makes the distribution of the social parasite B. flavidus the broadest of any bumble bee, broader than the known distribution of any nonparasitic bumble bee species. Color polymorphisms are retained across the range of the species, but may be influenced by local mimicry complexes. Following these results, B. flavidusEversmann, 1852 is synonymized with Bombus fernaldae (Franklin, 1911) syn. nov. and a subspecific status, Bombus flavidus appalachiensisssp. nov., is assigned to the lineage ranging from the Appalachians to the eastern boreal regions of the United States and far southeastern Canada.

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

Background: Correct species identification is the most crucial step in applying entomological evidence to estimate the postmortem interval (PMI) since death of decomposed corpses. Wing morphometrics have been proposed in species classification as an alternative method of traditional morphology and molecular approaches. However, so far, this method has not been applied to the identification of Chinese Calliphoridae and few studies compare the two identification methods.Methods: We used landmark-based geometric morphometrics of wings to identify nine medically and forensically important blow fly species of China. 270 specimens representing nine species and eight genera were sampled, 18 landmarks on the right wing were measured and analyzed using canonical variates analysis and discriminant function analysis. Then, a cross-validation test was used to evaluate reliability of the method. Moreover, in order to further assess the validity of this method, molecular identification is used for comparative analysis. Eighty sequences of cytochrome c oxidase subunit I (COI) of Calliphoridae isolated from different countries were downloaded from Genbank, including the data previously submitted by our team. Results: Different species and genera can be well separated through morphometric analysis with an overall classification accuracy of 80~100%, but discrimination between sexes was less effective. The results indicated that the discriminative efficiency of the two methods is almost identical.Conclusions: Wing morphometrics can be used as a complementary method of molecular identification for the geographical location and gender identification of certain species as a simple and cheap method.

Wing morphometrics reveals the migration patterns of Africanized honey bees in Northeast Brazil

Climatic differences can directly affect the population structure of organisms. The Northeastern Brazilian covers an area of about 1.5 million square kilometres, in which the semi-arid part corresponds to approximately 60%. It is probably the most vulnerable region to climatic variations in Brazil. Here, we investigated the variability of Africanized honey bees in different localities from Northeast Brazil during the dry season and the influence of drought periods in morphological variation among populations. Analyses were carried out with data collected by traditional and geometric morphometrics of bees sampled during the dry season and showed a subtle morphological variation in agreement to the climatic pattern. Furthermore, once we added samples collected during the rainy season, we observed a change in its pattern, with a very different result from the same population sampled during drought periods. The geometric morphometrics results emphasized that samples collected during the rainy season in Mossoró would be more similar to bees from humid coastal areas. These results probably reflect the probable dispersion pattern of these bees between humid coastal and semi-arid areas.