Alloperla deminuta Zapekina-Dulkeit, 1970

Judson, Sarah W. & Nelson, C. Riley, 2012, 3541, Zootaxa 3541, pp. 1-118 : 24

Alloperla deminuta Zapekina-Dulkeit, 1970

SYNONYMY

Alloperla deminuta Zapekina-Dulkeit, 1970

TYPE LOCALITY: USSR/ Siberia: Krasnojarsk, reservation “Stolbij”, Mana River .

DIAGNOSIS: This species is characterized by it lack of pronotal and abdominal pigmentation ( Fig. 92), whereas all other Alloperla from Mongolia have characteristic pigmentation ( Fig. 100,). A. deminuta does have some faint pigmentation on the inner margin of tergite 10 forming a rectangular outline around the epiproct origin ( Fig. 93), which A. joosti Zwick, 1972 lacks. Like A. joosti ( Fig. 97), the base of the epiproct is narrow and not as greatly swollen ( Fig. 109) as in A. mediata ( Fig. 101) and A. rostellata ( Fig. 105). In contrast to A. joosti , the tip of A. deminuta ’s epiproct is pointed ( Fig. 93) and without ventral spines. The epiproct is also shorter than in all other Mongolian Alloperla . The subgenitial plate of females is often difficult to discern due to lack of contrasting pigmentation ( Fig. 94). The plate is flat with a small subtriangular protrusion in the middle that barely extends over sternum 8. In other species, this plate is more pointed and much longer, usually covering more of sternum 9. Nymphs are readily distinguishable at the generic level, but comparative material was insufficient to define characters for separating species.

DISTRIBUTION—Global: East Palearctic— Regional: AOB, POB*— Aimag: AR, BU^, KhE*, KhG, OV^, SE, TO^, UB.

DISCUSSION: A. deminuta is the most commonly encountered Alloperla species in Mongolia and is found predominantly in the Selenge River Basin ( Fig. 95). This species is unique among Mongolian Chloroperlidae for its extreme lack of dark pigmentation.