Perlomyia gakken, Nakamine, 2022

Nakamine, Hiroshi, 2022, A New Species of Perlomyia (Insecta: Plecoptera: Leuctridae) from Japan, Species Diversity 27 (1), pp. 91-94 : 91-93

Family Leuctridae Klapálek, 1905 Subfamily Leuctrinae Klapálek, 1905 Genus Perlomyia Banks, 1906 Perlomyia gakken sp. nov. [New Japanese name: Gakken-hosokawagera] ( Figs 1, 2 )

Perlomyia sp. 2 BJQ: Inada 2011: 157–158, fig. H15.

Materials examined. Holotype: male ( LBM1410012536 ), Japan, Honshu, Kyoto Prefecture, Kyoto City, Sakyo Ward , Kurama-honmachi , 35.13°N, 135.78°E, alt. 300 m, the Kurama-gawa (Riv.), 18 March 2021, H. Nakamine leg. Palatype: male ( LBM1410012537 ), collected with holotype, H. Nakamine leg.

Diagnosis. Tergum 10 with small projections posterolaterally. Cercus with short terminal spine and small basodorsal lobe. Epiproct long and slender, slightly swollen at middle in lateral aspect, slightly curved anterior like a crochet hook shape at tip.

Description. Forewing length, holotype 6.2 mm, paratype 5.8 mm. Head blackish brown. Pronotum dark brown, longer than width, narrower than head. Mesonotum to abdomen dark brown to brown. Legs unifromly brown. Wings hyaline, vein pale brown.

Male terminalia: Tergum 9 narrowed mesally, lacks lobes, antecosta evenly curved. Tergum 10 divided, each sclerite with distinct small paired projections posterolaterally. Cercus with small spine-like apex, bearing a small basodorsal lobe, only slightly longer than width. Epiproct long and slender, with wide base, slightly swollen at middle in lateral aspect, slightly curved anterior like a crochet hook shape at tip. Sternum 9 narrowed apically, sharply curved dorsally in lateral aspect. Vesicle almost circular ellipse, broad near base, strongly narrowed at base in ventral aspect.

Female: Unknown.

Larva: Unknown.

Remarks. This new species is distinguished from the other 24 species of Perlomyia by having a remarkably long and slender epiproct with a crochet hook shape at tip. Although, this new species is most similar to P. kappa Sivec and Stark, 2012 , but can be discriminated from P. kappa by the following features: (1) cercus with small spine-like apex [long terminal spine in P. kappa ( Sivec and Stark 2012a: figs 16–18)], (2) epiproct slightly swollen at middle in lateral aspect [swollen basally in P. kappa (ditto: fig. 18), and (3) epiproct like a crochet hook shape apically in lateral aspect [expanded apically in lateral aspect in P.kappa (ditto: fig. 18)].

Etymology. The specific name is derived from the company name Gakken that produces illustrated books mainly for children, and this new species was discovered in the process of revising the book. Treated as indeclinable.

Figures

Fig. 2. Male tarminalia of Perlomyia gakken sp. nov. (paratype, LBM1410012537). A, Dorsal view; B, ventral view; C, left lateral view. Abbreviations: cr, cercus; ep, epiproct; pp, paraproct; S, sternum; T, tergum; v, vesicle. Scale bar: 0.2mm.