Nemoura arctica Esben-Petersen, 1910

Judson, Sarah W. & Nelson, C. Riley, 2012, 3541, Zootaxa 3541, pp. 1-118 : 33

Nemoura arctica Esben-Petersen, 1910

SYNONYMY

Nemoura arctica Esben-Petersen, 1910

TYPE LOCALITY: Norway .

DIAGNOSIS: The apical prongs of the epiproct ventral sclerite are broadly flattened with spines on the lateral margins ( Fig. 172, 173), whereas those in N. cinerea ( Fig. 178) and N. sahlbergi ( Fig. 187) are somewhat pointed and have only apical spines. Like N. cinerea ( Fig. 179), the outer (major) lobe of the paraproct is convex, but unique to N. arctica , it is divided by a broadly rounded notch that creates a inward tilted cup ( Fig. 174). The cerci have only 2 apical spines perpendicular to each cercus. The female subgenital plate is broadly rounded and not particularly diagnostic due to variation within the species. The nymphs of N. arctica , like N. sahlbergi , have hairs on the galea, which N. cinerea nymphs lack. Nemoura arctica nymphs also have long hairs at the corners of the pronotum and short hairs along the remainder of the pronotal margin, whereas N. sahlbergi has only short hairs at the corners that are equal in length to those lining the pronotal margin. If distal cercal segments are intact, they have intrasegmental hairs which N. sahlbergi lacks.

DISTRIBUTION—Global: Holarctic— Regional: AOB, IDB, POB*— Aimag: AR, BO, BR*, BU^, DO*, GA*, KhD, KhG, SE, TO, UB, UV*, ZA*.

DISCUSSION: This species is the most common Nemouridae in Mongolia and was found in all regions targeted by our expedition ( Fig. 175). Adults are found in high abundances during July.