Paraleuctra paramalaisei, Murányi & Hwang, 2017

Murányi, Dávid & Hwang, Jeong Mi, 2017, Four new species and further contributions to the Leuctridae (Plecoptera) of the Korean Peninsula, Zootaxa 4282 (1), pp. 43-61 : 47-49

Paraleuctra paramalaisei sp. n.

( Figs. 4–6, 8, 10 )

Type material. Holotype male: SOUTH KOREA: CB, Danyang-gun , Gagok-myeon, Eouigok-ri, Saebat , 25.v.2012, leg. Y.J. Bae ( KUEM) . Paratypes: CB, Danyang-gun , Gagok-myeon, Eouigok-ri, Saebat , 25.v.2012, leg. Y.J. Bae; 2♀ ( KUEM), 2♀ ( NIBR) .

Diagnosis. Male: Tergum X with two rounded posterior lobes separated by a U-shaped notch with evenly curved sides. Subgenital plate separated, posterior portion deeply divided. Subanal probe long and slender, stem strongly sclerotized; apex with paired small, globular ventral lobes and large, hardly divided dorsal lobe. Epiproct small, hooked. Cercus slender, bearing two apical teeth. Female: not distinguishable from other occidentalis group members: subgenital plate large, posterior edge with two short and wide, rounded lobes; separated from lateral edges of tergum.

Description. Medium sized species, macropterous. Forewing length: holotype 4.6 mm, female paratypes 5.6– 6.0 mm; body length: holotype 5.1 mm, female paratypes 4.6–5.5 mm. Head dark brown without distinct rugosities; antennae dark brown, palpi paler. Pronotum same colour as head, longer than wide, slightly narrower and shorter than head; rugosities distinct. Meso- and metathorax brown, without characteristic pattern. Legs uniformly brown; wings brownish, venation brown. Setation generally short.

Male abdomen ( Figs. 4–6, 8 ): Antecosta interrupted on terga I–III, entire on terga IV–IX, terga I–II with a median membranous field. Tergum IX not raised, posterolateral edges with longer setae. Tergum X with strong and curved antecosta, connected to a distinct median furrow that reaches the posterior edge; posterior edge with two rounded lobes separated by an U-shaped notch as wide as one third segment's width, lobes not raised in lateral view. Epiproct small, with swollen base and curved, hook-like apex. Sternum IX with large ventral lobe, fully covered by strong setae. Subgenital plate fully separated from other sclerites, anterior edge rounded. Posterior portion deeply divided into thin lateral lobes, surrounding the subanal probe that rests within the U-shaped notch. Subanal probe formed from the paraprocts is long and slender, with U-shaped base and stem strongly sclerotized all along to the apical lobes but with a light ventral stripe. The apex bears one pair of short ventral lobes and much larger, weakly divided dorsal lobes; all are covered with small, triangular scales. The ventral lobes are globular, not extending laterally, positioned more apically than the origin of the dorsal lobe but by far not reaching the tip; length of dorsal lobe is about one third of the length of stem after its sharp forward bend, basal portion weakly subdivided, slightly expanding laterad, the posterior portion of the lobe covers the sclerotized tip. Cercus slender, basal portion extended in narrow rods connected to base of the subanal probe, apex slightly bulging beneath the two apical teeth; the dorsal tooth is larger, both downcurved and slightly point inwards, apical wart indistinct.

Female abdomen ( Fig. 10 ): Terga I–IX membranous but with transverse row of four pigmented spots; a medial sclerotized patch also present on tergum IX. Tergum X fully sclerotized. Sterna I–VI simple. Sternum VII rectangular and unmodified, not fused to sternum VIII. Subgenital plate large, base partly hidden beneath sternum VII and subdivided into three pigmented areas by two pale triangles. Caudally diverging strongly and ending in rounded lobes weakly separated by a wide shallow indentation; the lobes are overhang sternum IX, greatest width of plate equals two thirds of segment's width. The plate is evenly brown, bears dense and long setae, it is almost touching but not fused with lateral edges of tergum. Sternum IX simple, sternum X interrupted in the medial fourth. Paraproct and cercus simple.

Affinities. The species belongs to the P. occidentalis species group sensu Stark & Kyzar (2001), and is closely related to P. malaisei , other Korean endemic of this Transpacific group. The males can be distinguished by the apex of subanal probe and posterior lobes of tergum X: P. malaisei has large and laterally expanded ventral lobes and a rather small dorsal lobe of the apex of subanal probe, whereas the dorsal lobe of P. paramalaisei is much larger than the small ventral lobes ( Figs. 6–7 ). The posterior lobes of tergum X are more pronounced in P. malaisei with their inner edges nearly parallel to the segment's lateral edges, while the inner edge evenly curves into the caudal notch in P. paramalaisei ( Figs. 8–9 ). The female is indistinguishable from the other Asian species of the P. occidentalis group.

Distribution. Known only from northern Sobaek Mountain Ranges of South Korea ( Fig. 31 ).

Etymology. The name paramalaisei refers to the morphological similarity with the other South Korean endemic Paraleuctra species, P. malaisei .

Figures

FIGURES 4 – 10. Terminalia of Korean endemic Paraleuctra Hanson, 1941 species— 4 – 6, 8, 10: P. paramalisei sp. n., male holotype and female paratype, South Korea, Chungcheongbuk Province; 7, 9: P. malaisei Zwick, 2010, South Korea, Gangwon Province; 4: male terminalia, lateral view; 5: male terminalia, oblique ventrocaudal view; 6 – 7: male subanal probe, lateral view; 8 – 9: male terminalia, dorsal view; 10: female terminalia, ventral view—scale 0.5 mm.

FIGURES 26 – 31. Korean distribution of the genera Despaxia Ricker, 1943, Leuctra Stephens, 1836, Megaleuctra Neave, 1934 and Paraleuctra Hanson, 1941 — 26: Despaxia asiatica Zwick, 2010; 27: Leuctra fusca tergostyla Wu, 1973; 28: Megaleuctra saebat Ham & Bae, 2002; 29: Paraleuctra cercia (Okamoto, 1922); 30: P. malaisei Zwick, 2010; 31: P. paramalaisei sp. n. (circle with central dot) and Paraleuctra sp., occidentalis group (open circle) — circle with central dot indicates type locality.