Chalarus Walker, 1834

Kehlmaier, Christian & Assmann, Thorsten, 2008, The European species of Chalarus Walker, 1834 revisited (Diptera: Pipunculidae), Zootaxa 1936, pp. 1-39 : 17-18

publication ID	https://doi.org/ 10.5281/zenodo.184950
DOI	https://doi.org/10.5281/zenodo.5622194
persistent identifier	https://treatment.plazi.org/id/367D87D6-FFD2-8D65-FF78-F9EBFD0AE0E0
treatment provided by	Plazi
scientific name	Chalarus Walker, 1834
status

Treatment

Chalarus Walker, 1834 View in CoL View at ENA

Chalarus Walker, 1834: 269 View in CoL .

Type species: Cephalops spurius Fallén, 1816 , by subsequent designation ( Westwood, 1840: 135).

The main morphological autapomorphy of the genus, that readily distinguishes it from any other Pipunculidae , is the reduced wing venation with its open discal cell and a poorly developed anal vein. As for male genitalia, unlike the remaining Chalarinae , the phallic processes do not branch off from the base of the phallus (see Kehlmaier 2006) but distally together with the membranous tip of distiphallus, and can be reduced or secondarily lost. These phallic processes, as well as the tip of the distiphallus, are highly diverse in length and shape and represent the main features enabling recognition of most species. Additional structures exhibiting interspecific genital variability on species or species group level are the degree of curvature and width of the phallic shaft, the placement of the two lower ejaculatory ducts, the shape of the ejaculatory apodeme as well as the shape of the gonopods and surstyli (see Figs 1–33 View FIGURES 1 – 6 View FIGURES 7 – 11 View FIGURES 12 – 23 View FIGURES 24 – 33 ). Hence, for a successful identification it is inevitable to dissect and study male genitalia with care at a magnification of at least 50. In females, species identification can be achieved by focusing on the size of the enlarged frontal ommatidial facets, the degree of narrowing of the frons, coloration of legs and body hairs, size of pulvilli and shape of the ovipositor. In some cases, it is advisable to remove the latter from the abdomen and study it from lateral, dorsal and ventral views.

Apart from the newly described taxa, the morphological investigation of the material plus the obtained barcoding data result in additional observations with taxonomic implications. In the following, the European Chalarus are briefly characterised and discussed.