Geometric morphometrics in mosquitoes: What has been measured?

The field of morphometrics is developing quickly. Recent advances have enabled geometric techniques to be applied to many zoological problems, particularly those involving epidemiologically-relevant mosquitoes. Herein, we briefly introduce geometric morphometric (GM) techniques and then review selected groups of mosquitoes (Culicidae) to which those techniques have been applied. In most of the reviewed cases, GM was capable of satisfactorily discriminating among the tested groups primarily when the studies considered differences within and among species, sexual dimorphism, treatments and the separation of laboratory strains. Although GM approaches have developed quite rapidly, some caution must be taken during data processing for a reliable biometrical approach, such as allometry and asymmetry analyses, scale removal and wing clarification staining for landmark digitization. We also critically forecast directions in this field and discuss how the creation of image databases should enhance species identification in culicids.