Beardius Reiss et Sublette

Pinho, Luiz Carlos, Mendes, Humberto Fonseca & Andersen, Trond, 2013, Revision of Beardius Reiss et Sublette, 1985 (Diptera: Chironomidae), with the description of twenty new species, Zootaxa 3742 (1), pp. 1-78 : 4-5

Beardius Reiss et Sublette

Beardius Reiss et Sublette, 1985: 175 .

Beardius Reiss et Sublette ; Andersen & Saether (1996: 34), Jacobsen & Perry (2000: 130).

Type species: Beardius parcus Reiss et Sublette, 1985: 183 , by original designation.

Other included species: Beardius abbadi sp. n.; B. aciculatus Andersen et Saether, 1996 ; B. arawak sp. n.; B. bizzoi sp. n.; B. breviculus Reiss et Sublette, 1985 ; B. bucephalus sp. n.; B. chapala sp. n.; B. cristhinae Trivinho-

Strixino et Siqueira, 2007; B. curticaudatus sp. n.; B. dioi sp. n.; B. fittkaui Pinho, Mendes et Andersen, 2009 ; B. hirtidorsum sp. n.; B. krenak sp. n.; B. kumadueni sp. n.; B. lingulatus Andersen et Saether, 1996 ; B. longicaudatus sp. n.; B. mileneae sp. n.; B. nebularius sp. n.; B. neusae sp. n.; B. novoairensis sp. n.; B. phoenix sp. n.; B. phytophilus Trivinho-Strixino et Strixino, 2000 ; B. reissi Jacobsen, 2000 ; B. roquei Trivinho-Strixino et Siqueira, 2007 ; B. sapiranga sp. n.; B. triangulatus Andersen et Saether, 1996 ; B. truncatus Reiss et Sublette, 1985 ; B. tupinamba sp. n.; B. urupeatan Pinho, Mendes et Andersen, 2009 ; B. vanessae sp. n.; B. xylophilus Trivinho- Strixino et Strixino, 2000; B. yperoig sp. n.

The diagnosis of the adults is emended based on Andersen & Saether (1996) and Jacobsen & Perry (2000). When describing the new species it became evident that the structure previously regarded as the median volsella in fact is two different structures. Previously the median volsella in Beardius has been regarded as a very plastic structure, varying from a low wart-like tubercle bearing long setae as in B. phytophilus ( Fig. 1 ), to a long, triangular to rounded microtrichiose projection as in B. lingulatus ( Fig. 3 ) and B. urupeatan ( Fig. 6 ), sometimes bearing long lamellae as in B. xylophilus ( Fig. 151 ). However, in the hypopygium of for instance B. phoenix sp. n. or B. dioi sp. n. two structures which can be interpreted as the median volsella are evident, both a proximal wart-like tubercle and a distal microtrichiose projection ( Figs 2, 7, 8 ). The median volsellae in other Chironomini genera are usually either wart-like, as in Microtendipes Kieffer and Oukuriella Epler , or somewhat longer and cylindrical, as in Nilothauma Kieffer and Paratendipes Kieffer , both types bearing one to several apical setae. Thus, the median volsella in Beardius is most likely to be the proximal wart-like tubercle with strong apical setae, as described for B. phytophilus , B. cristhinae , B. roquei , B. parcus and B. reissi .

The distal microtrichiose “median volsella” is to a varying degree attached to the inferior volsella ( Figs 8–10 ) and in some of the new species, like in B. phoenix sp. n. ( Fig. 2 ), B. arawak sp. n. ( Fig. 4 ), and B. novoairensis sp. n. ( Fig. 5 ) arises from the very base of the inferior volsella. This structure is thus regarded as part of the inferior volsella and is called the basal lobe or basal projection of the inferior volsella below.

Both structures, the median volsella and the microtrichiose projection of the inferior volsella may be present or absent and the description of some of the previous named species is emended below accordingly. However, when only one structure is present, our interpretation might be questionable for a few species. We have for instance interpreted the structure in B. curticaudatus sp. n. and B. xylophilus sp. n. as being a projection of the inferior volsella rather than a median volsella, even though it might resemble the median volsella in many Tanytarsini species.

Figures

FIGURES 1–10. Variation in the median volsella (mv) and the basal lobe of the inferior volsella (bl) in male Beardius. 1–3— hypopygium, dorso-ventral view; 4–8—hypopygium, lateral view, 9–10—inferior volsella with basal lobe. — 1—B. phytophilus Trivinho-Strixino et Strixino; 2—B. phoenix sp. n.; 3—B. lingulatus Andersen et Saether; 4—B. arawak sp. n.; 5— B. novoairensis sp. n.; 6—B. urupeatan Pinho, Mendes et Andersen; 7—B. phoenix sp. n.; 8—B. dioi sp. n.; 9—B. bizzoi sp. n.; 10—B. mileneae sp. n. — (3—redrawn after Andersen & Saether (1996); 6—redrawn after Pinho et al. (2009)).

FIGURES 150–151. Beardius xylophilus Trivinho-Strixino et Strixino, male. 150—anal point and tergite IX and dorsal aspect of left gonocoxite and gonostylus; 151—hypopygium with anal point and tergite IX removed, left dorsal aspect, right ventral aspect.