3541 Author Judson, Sarah W. Author Nelson, C. Riley text Zootaxa 2012 2012-11-06 3541 1 118 journal article 1175­5334 505937B0-9F57-4068-82E6-8553826DD5AA Alloperla joosti Zwick, 1972 SYNONYMY Alloperla joosti Zwick, 1972 TYPE LOCALITY: Mongolia : Arkhangai aimag , Somon Chencher at Urd-Tamir Gol . DIAGNOSIS: This species characterized by reduced pigementation, with only a prominent dorsal abdominal stripe originating on segment 1 and continuing through segment 7 ( Fig. 96 ). The majority of Chloroperlidae of Mongolia, including A. rostellata ( Fig. 104 ) and A. mediata ( Fig. 100 ), possess this abdominal stripe but usually have additional pigmentation. In A. joosti , the meso- and metanota have only faint pigmentation at their periphery and, similar to A. deminuta , A. joosti lacks pigmentation on the pronotum. The epiproct of A. joosti is recurved anteriorly, the anteriorly directed portion is slightly swollen at its base and after a brief constriction, is uniformly narrow ( Fig. 97 ), with the length approximately four times the width. The apex of the epiproct is rounded ( Fig. 97 ), whereas it is pointed in all other Alloperla ( Fig. 93 , 101 ). The epiproct of A. joosti has spines along the ventral margin (best seen laterally), similar to A. rostellata ( Fig. 104 ) and A. mediata ( Fig. 100 ), but which A. deminuta lacks entirely. The female subgenitial plate of A. joosti ( Fig. 98 ) is often difficult to discern due to lack of contrasting pigmentation. The plate gradually slopes to an abrupt point, forming a triangle with a broad base, and extends only slightly over sternum 8. The nymphs are readily distinguishable to the generic level and we did not have enough material to attempt species separation. DISTRIBUTION—Global: East Palearctic— Regional: AOB- Aimag: AR, BU^, KhG^, OV^, SE^, TO^, UB, ZA. DISCUSSION: This species was originally described from Mongolia (Zwick 1972) and has been documented throughout the eastern Palearctic (Teslenko & Bazova 2009), including additional collections in Mongolia (Zhiltzova 1982). Among Mongolian Chloroperlidae , the epiproct of A. joosti superficially resembles that of Alaskaperla longidentata ( Fig. 111 ), but the epiproct of Ala. longidentata has no swollen base, is upturned, and very smooth on all sides especially lacking ventral spines.