Paraleuctra cercia ( Okamoto, 1922 )

Zwick, Peter, 2010, New Species And New Records Of Plecoptera From Korea And The Russian Far East, Illiesia 6 (9), pp. 75-97 : 89-90

Paraleuctra cercia ( Okamoto, 1922)

( Figs. 42, 43 )

Leuctra cercia Okamoto, 1922:37 . Syntypes from JAPAN, Sapporo, Shiribeshi, and Iburi provinces in coll. Okamoto not located ( Shimizu 2000).

Material examined. REPUBLIC OF KOREA: Gangwondo, Pyeongchang, Yongpyeong Myeon, Nodong-li, Nodong Valley, Alt. 900 m, 5.- 14.6. 2008, 37°42.08. N' 128°28.89'E, 3 Malaise traps in shade at small stream, 1♀. Chungbuk, Sangchon-Myeon, Dungeon-li near Doma Pass, Alt. 750 m, 2.-26. V. 2006, 2 Malaise traps in forest on small stream, 15♀.

Notes. The identification of the present material is not without doubt. Descriptions and illustrations ( Okamoto 1922, Zhiltzova 1974, 2003, Shimizu 2000) are of a female with basally smooth subgenital plate. Conspicuous pilosity occurs only on the caudal lobes. The female from Nodong Valley listed above agrees with this description. The Korean specimens from near Doma Pass differ by a setose crest which in lateral view rises medially from the anterior third of S8, resembling a cone (Figs. 30, 31). Its strong setae are strikingly apparent in lateral view.

Initially, these crested specimens were thought to represent a new species. However, V. Teslenko (in litt.) kindly translated the key passage to females of this group ( Zhiltzova 2003) which reads:

- ... Lateral margins of lobes of subgenital female plate truncated obliquely, basal part of subgenital plate transfers to distal part without distinct projection ................................ araleuctra zapekinae - ... Lateral margins of lobes of subgenital female plate are parallel, basal part of subgenital plate narrow, separated from wide distal part by distinct projection ......................... Paraleuctra cercia

A sample I took near Sidima, Khabarovski Territory, Russian Far East, in June 1998 includes the nicely distinct males of both species. Of the 6 females, 4 have a smooth subgenital plate as published in the literature. However. one female resembles the Korean specimens ( Figs. 42-43 ) and the last specimen is intermediate.

Figures

Figs. 42-43. Paraleuctra cercia, aberrant Korean female with a cone on the subgenital plate. 42, abdominal tip in ventral, 43, in lateral view. Not to scale.