Chrysotus laesus

Wei, Lianmeng & Zhang, Lili, 2010, A taxonomic study on Chrysotus Meigen (Diptera: Dolichopodidae) from southwest China: descriptions of eleven new species belonging to the redefined C. laesus - group, Zootaxa 2683, pp. 1-22 : 3

Chrysotus laesus species-group

Diagnosis. The C. laesus -group is herein redefined and can be distinguished from other members of Chrysotus by the following features: Epandrium with angular projection posteriorly ( Fig. 2 , peap). Hypandrium with process at apex. Postocular and occiput with setae usually black, seldom pale. Proboscis and palpus usually blackish brown, sometimes brownish black, seldom yellowish. Legs usually brownish black or black, at most individual species with femora yellowish at tip, with tibiae always more or less yellow (except C. laesus with tibiae black); sometimes with coxae and femora dark metallic green. Fore coxa usually with black setulae and setae anteriorly, but individual species with pale setulae and setae anteriorly (e.g., C. laesus , C. pallidus and C. serratus ). Femora without row of long and developed setae (except C. guizhouensis with femora bearing two rows of long ventral setae). Base piles on anterior surface of hind tibia normal (fore, mid and hind tibiae with same base piles on anterior surface and vast majority of more than 150 species that have been found in Guizhou Province bear longer and denser basal piles on anterior surface of hind tibia). Halter usually pale at most brown or brownish black basally (except C. guizhouensis with halter brown).

The Chrysotus laesus -group includes the following species:

C. adunatus sp. nov. (Guizhou: Anshun, Jiaozishan, 1400 m)

C. agraulus sp. nov. (Guizhou: Anshun, Ganpu, 1250 m)

C. anshunus sp. nov. (Guizhou, Anshun, Jiaozishan, 1400 m)

C. apicicaudatus sp. nov. (Guizhou: Daozhen, Dashahe, 1400 m)

C. biprojicienus sp. nov. (Guizhou: Shibing, Yuntaishan, 700 m)

C. brevicercus Wang & Yang, 2009 (North China, Henan and Shandong)

C. fanjingshanus sp. nov. (Guizhou: Fanjingshan, 1800 m)

C. fuscitibialis sp. nov. (Guizhou, Anshun, Jiaozishan, 1400 m)

C. guizhouensis Wang & Yang, 2009 (Guizhou, Daozhen, Dashahe, 1700 m)

C. laesus (Wiedemman, 1817) (Palaearctic: England, Sweden, Denmark, Finland, Norway, France, Netherland, Switzerland, Austria, Germany, Belgium, Italy, Belarus, Spain, Poland, Hungary, Romania, Czech, Slovakia, Slovenia, Bulgaria, Yugoslavia, Estonia, Russia, Ukraine, Kazakhstan, China)

C. laxifacialus sp. nov. (Guizhou: Chishui, Dagangou, 100 m)

C. nudisetus Negrobov et Maslova, 1995 (Palaearctic: Russia)

C. pallidus sp. nov. (Guizhou: Zhenning, Bahe and Qianxi, Bailidujian, 1100–1800 m)

C. serratus Wang & Yang, 2006 (North China, Beijing, 557–1330 m)

C. trapezinus sp. nov. (Guizhou: Zhenning, Bahe, 1100 m)

C. xinanus sp. nov. (Guanxi, Sichuan and Yunnan, 700–1800 m)

Distribution. Oriental and Palaearctic regions.

Remarks. Prior to this study, two Palaearctic species-groups, C. cilipes -group and C. laesus -group were recognized by Negrobov (1980). Unfortunately, they were poorly defined on the basis of “light setae on fore coxae”, and this feature is mostly unique to C. laesus , C. pallidus and C. serratus . In the above list of diagnostic characters, the posterior angular projection of the epandrium is found only in the C. laesus -group, a unique synapomorphy, and the remaining diagnostic characters above are usually present in the 16 new and known species. This derived character provides evidence for the re-evaluation of the C. laesus -group and consequently we have redefined the species-group in order to help organize and classify this large genus group.

Figures

FIGURE 2. Chrysotus agraulus sp. nov., male terminalia, left lateral view. Abbreviations: apgon, arms of postgonite; appgon, anterior process of postgonite; cerc, cercus; ejap, ejaculatory apodeme; hyp, hypandrium; lel, lateral epandrial lobe; ph, phallus; peap, posterior epandrial angular projection; sur, surstylus; vpe, ventral projection of epandrium.