Brachycentrus subnubilis Curtis 1834

Konovalova, Daria A., Kislitsina, Nadezhda I. & Zotina, Tatiana A., 2023, Assemblages of Trichoptera larvae on water moss in the middle reaches of the Yenisei River (Siberia, Russia), Zootaxa 5306 (3), pp. 331-348 : 341

Brachycentrus subnubilis Curtis 1834 .

The mesonotum always consists of pairs of sclerites; each metathorax epimeron has a brush of long setae on the anterior edge ( Fig. 10A ). The setae of the mesonotal sclerites are closely adjacent to the posterior edge ( Fig. 10A ). The inner anterior corner of each submesal mesonotal sclerite has 2-4 setae ( Fig. 10A ). The mid- and hind tibiae each have a large apicoventral protrusion bearing a large apical bristle ( Fig. 10B ). The dorsal edges of the middle and hind femora have several secondary setae ( Fig. 10B ); the ventral edges of these femora each has a dense row of short filtering hairs and two long bristles, there are no hypertrophic setae ( Fig. 10B ). The larval case is a slightly conic tetrahedral tube square in cross-section ( Figs 10C, 10D ) up to 1 cm long. A case is constructed from leaves of water moss arranged transversely. Two types of cases were found in our samples. One type has regular transverse ribs on the case surface, which are clearly seen with the naked eye or at a low magnification, and fragments of water moss shoots are embedded in cases at the frontal or distal or both ends of the tube ( Fig. 10C ). Cases of the other type have a smooth surface, but regular structures formed by leaves of water moss embedded at right angles to the longitudinal axis of the case are visible at microscopic magnification ( Fig. 10D ). This species was low in numbers but regularly found in the Trichoptera assemblages on water moss.

Figures

FIGURE 10. Larva and case of Brachycentrus subnubilis Curtis 1834. 10A, habitus, dorsal; 10B, right middle (top) and hind (bottom) legs, anterior faces (arrows: secondary setae); 10C, cases, right lateral; 10D, case, right lateral face and edge of the tetrahedral conic case structure. Scale bars 10A, 10C, 10D = 3 mm; 10B = 1 mm.