Perlomyia angulata, Sivec & Stark, 2012

Sivec, Ignac & Stark, Bill P., 2012, The Genus Perlomyia Banks In Taiwan (Plecoptera: Leuctridae), Illiesia 8 (11), pp. 119-124 : 119-121

Perlomyia angulata sp. n.

( Figs. 1-4 )

Material examined. Holotype ♂, paratypes 2♂, 1♀, Taiwan: Taichung County, W Lishan , 1600 m, 24°16’39’’N, 121°13’28’’E, 22 March 1996, I. Sivec, B. Horvat (holotype, paratype ♀ PMSL, 2♂ paratypes BPS). Additional paratypes: Taiwan: Hualien County, S Tayuling, 2330 m, 24°11’17’’N, 121°20’30’’E, 13 April 1996, I. Sivec, B. Horvat, 2♂, 5♀ ( PMSL). Nantou County, Chiton, 4 February 1995, 2♂, 1♀ ( PMSL); E Songchuangkang, 2570 m, 24°11’21’’N, 121°18’35’’E, 22 March 1996, I. Sivec, B. Horvat, 1♂ ( PMSL). Taichung County, E Chuyunshan, 2200m, 24°24’16’’N, 120°52’45’’E, 24 March 1996, I. Sivec, B. Horvat, 2♂ ( PMSL); Wulin, Sheipa National Park, 1950 m, 29 October 1996, I. Sivec, 11♂, 13♀, 1 larva ( PMSL), 5♂, 5♀ ( BPS); Wulin, Sheipa National Park , 1900 m, 24°23’46’’N, 121°18’31’’E, 28 October 1996, I. Sivec, 2♀ ( PMSL).

Adult habitus. General color dark brown to black, typical of genus.

Male. Forewing length 6 mm. Epiproct short in dorsal aspect, slender and bent sharply near midlength in lateral aspect ( Figs. 1, 3 ). Sclerite of tergum 9 broadly excavated posteromesally, small knobs absent from tergum 10 ( Fig. 1 ). Cerci bearing a small dorsobasal lobe and a small apical spine ( Figs. 1-3 ). Paraprocts fused into a broad, thick process, bent dorsad at a right angle on the ventrocaudal margin ( Fig. 3 ). Apex of sternum 9 triangular in ventral aspect ( Fig. 2 ) and curved upward in lateral aspect ( Fig. 3 ). Vesicle short and rounded on apical margin.

Female. Forewing length 7 mm. Posterior margin of sternum 7 produced into a rounded or slightly triangular projection which slightly overlaps the base of sternum 8. Sternum 8 bearing a pair of median, rectangular shaped sclerites, narrowly separated by a membranous strip; sclerites extend over apex of sternum 9 ( Fig. 4 ); basolateral wing-like sclerites attached at mesolateral margins of median sclerites.

Larva. Undescribed.

Etymology. The species name refers to the angular form of the epiproct in lateral aspect.

Diagnosis. Perlomyia angulata does not appear to be closely related to any of the known species. The strongly bent epiproct in lateral aspect, with blunt apex and the absence of knobs on tergum 10 is apparently unique to this species. Among Taiwanese species the male is more similar to P. taiwanensis (described below) but that species lacks the slender angular epiproct and also has knobs on tergum 10. Females are similar to P. excavata in having abdominal sternum 7 projecting over the base of 8, but these are distinct by virtue of the lateral winglike sclerites of sternum 8 being connected to the posterolateral margins of the median sclerites in P. angulata but connecting to the anterolateral margins in P. excavata .

Figures

Figs. 1-4. Perlomyia angulata. 1. Male abdominal terga 8-10. 2. Male abdominal sterna 8-10. 3. Male abdominal segments 9-10, lateral aspect. 4. Female abdominal sterna 7-10.