Psilotreta moritai, Kawase, 2021

Kawase, Naoki, 2021, Description of three new species of Psilotreta (Trichoptera: Odontoceridae) from Japan, Zootaxa 4980 (3), pp. 589-598 : 593-595

Psilotreta moritai sp. nov.

( Figs 3A–3L )

Psilotreta sp. Morita 2006: 201 .

Diagnosis. The male of this species is similar to that of P. voluta sp. nov., but can be distinguished from the latter by the following male genital structures: (1) the basal segment of each inferior appendage is thick and clearly dilated at the middle in lateral view (slender and almost cylindrical in P. voluta ); (2) the preanal appendages are broadly oval, 2.5 times as long as wide in lateral view (more slender, about 4 times as long as wide in P. voluta ); (3) each lateral process has a short, almost straight, sword-like ventral projection directed anterad with a slightly rounded or truncate apex (in P. voluta , the ventral projection is curved anteroventrad with an acutely pointed apex); (4) each intermediate appendage lacks spines on the outer edge (in P. voluta , each intermediate appendages has one (or two) spine(s) along the outer edge); and (5) the aedeagus has a membranous protrusion dorsally on the surface in lateral view (in P. voluta , with no protrusions dorsally on the surface).

Adult Male. General coloration reddish to pale brown for body, antennae, and wings. Maxillary palps approximately same as for P. voluta sp. nov. Head in dorsal view similar to that of P. voluta sp., but oval anterior and posterior warts smaller ( Fig. 3A ). Length of each male forewing 7.0– 7.3 mm (mean = 7.18 ± 0.11, n = 4). Venation similar to that of P. voluta sp. nov., but discoidal cell of male hind wings open in two of five specimens examined in this study ( Fig. 3B ).

Male Genitalia ( Figs 3C–3L ). Tergum IX subtriangular in dorsal view, with steep sides below basal setal warts. Basal segment of each inferior appendage thick, dilated at middle in lateral view and covered with setae, extending to posterior margin of preanal appendages; apical segment nearly 2/3 as long as basal segment in lateral view, cylindrical, with many brown teeth on apical half. Preanal appendages broadly oval in lateral view, compressed. Segment X with median dorsal process apically clavate, bearing several setae around apex; lateral processes each with ventral projection heavily sclerotized, stout and directed straight anterad, with its base derived from very posterior end of lateral process or just at base of its intermediate appendage ( Figs 3D–3G ); each intermediate appendage heavily sclerotized, curved posterad and ventrad in lateral view, ending in acute apex directed ventrad (or rarely posterad).

Phallus with phallotheca long, cylindrical; endotheca with pair of parameres, each only about 4 times as long as its basal width in ventral view; aedeagus with membranous protrusion dorsally, ventral plate slightly sclerotized, membranous apex slightly truncate and dilated, internal phallotremal sclerite strongly curved toward apex, L-shaped in lateral view, moderately broadened apically in ventral view ( Figs 3K, 3L ).

Female, Larva, Pupa. Unknown.

Holotype. male (in alcohol), Japan, Honshu, Mie, Kumano-shi, Hobo-cho (Tategasaki), 33°56'N, 136°11'E, alt. 50 m, 31.v.2006, N. Kawase ( LBM141001210 ).

Paratypes. Japan, Honshu, Mie: 1 male, same data as holotype ( LBM141001211 ) ; 2 males, same locality as holotype, 1.vi.2002, H. Morita ( MKNC2021017–18 ) ; 1 male, Owase-shi, Mikisato-cho , 33°59'N, 136°10'E, 16.vii.2016, H. Morita ( MKNC2021019 ) ; 1 male, Kihoku-cho, Aiga , 34°07'N, 136°10'E, 2.vii.2016, H. Morita ( CBM0180207 ) .

Etymology. The Latin species epithet moritai is derived from Hisayuki Morita who first collected specimens of this species.

Distribution. Central Honshu (Kii Peninsula).

Habitat and Biology. Adults were collected around mountainous streams at light from May to July.

Japanese name. Morita-kiso-tobikera.

Figures

FIGURE 3. Psilotreta moritai sp. nov. 3A, male head, dorsal; 3B, male right wings, dorsal; 3C–3L, male genitalia: 3C, left lateral; 3D, left lateral process & intermediate appendage, left lateral (3E–3G, variations); 3H, dorsal; 3I, variation of median dorsal process; 3J, ventral; 3K, phallus, left lateral; 3L, same ventral.Abbreviations: int.app. = intermediate appendage (paired), lat.pr. = lateral process (paired), mdp. = median dorsal process; v.pr. = ventral projection (paired).