Mnesibulus laguna, Tan & Gorochov & Baroga-Barbecho & Yap, 2020

Tan, Ming Kai, Gorochov, Andrei V., Baroga-Barbecho, Jessica B. & Yap, Sheryl A., 2020, New data on some crickets of the subfamilies Landrevinae, Phaloriinae and Podoscirtinae (Orthoptera: Grylloidea) from Laguna (Philippines: Luzon Island), Zootaxa 4809 (1), pp. 29-55 : 34-38

Mnesibulus laguna new species

( Figs. 3 , 4 )

Material examined. Male holotype (UPLG.19.41), Philippines, Luzon Island, Laguna, Paete , Barangay Ilaya, UP Land Grant, N14.39826, E121.55703, 401.1± 6.5 m.a.s.l., 1417 hours, 6 September 2019, under foliage, coll. M. K. Tan, J. B. Baroga-Barbecho, C. C. Lucañas and S. A. Yap, pinned and genitalia dissected ( UPLBMNH) .

Diagnosis. This new species differs from all known congeners by the combination of these characters: abdominal gland with posterior margin of fifth segment rectangularly, emarginated in middle, tubercle on sixth segment with anterior apex triangular and apex; anal plate deeply and narrowly excised in middle, lateral of excision with dense strong setae pointing posteriorly, with a dorsal oval plate slightly surpassing lateral lobes, with posterior margin somewhat truncated; apical epiphallic process large, extending beyond lateral margin of epiphallus, curved anteriorly at apex into a hook-like acute apex; mold of the spermatophore attachment plate with anterior end broadly rounded with two pyriform lateral lobes joined together by a narrow ‘bridge’ in the middle; apical process of rachis produced well beyond apex of epiphallus, enlarged at apex and unique shape.

Comparison with congeners. The male genitalia is most similar to M. pallidulus Bolívar, 1889 from Sibul in Luzon Island (unclear whether it is referring to Sibul in Bataan or Bulacan) but differs by: apical epiphallic process longer and extending beyond lateral margins of epiphallus and with apex of process more strongly curved; mold of the spermatophore attachment plate transversely oval with anterior end broadly rounded (instead of lobular in the middle). It also differs by male ninth abdominal tergite much more elongated than supra-anal plate (shorter in M. pallidulus ) and with a distinct longitudinal fissure in middle (absent in M. pallidulus ); and by male metanotal gland.

The new species is also similar to M. bicolor (Haan, 1844) from Java, M. luzoni Gorochov, 2003 from Batangas in Luzon Island but differs by epiphallus distinctly slenderer, apical epiphallic process (term sensu Gorochov, 2003) larger and more strongly curved with apex acute and hooked (not strongly curved and without hooked apex in M. bicolor and shorter and faintly curved in M. luzoni ); apical part of guiding rod (= rachis) with widened apex more longitudinally oblong and well surpassing posterior apex of epiphallus (transversely oblong in M. bicolor and rounded in M. luzoni ); ectoparameres longer, also surpassing posterior end of epiphallus and more strongly curved at apex than M. bicolor and M. luzoni , and slenderer at apex than M. luzoni .

The mirror area of tegmen also differs with that of M. bicolor and M. luzoni : anterior half (with straight veins) as long as posterior half, unlike M. bicolor (anterior half shorter); transverse veins more similar to that of M. bicolor .

The new species also differs from other species from the Philippines: M. lineolatus Stål, 1877 ( M. simodus Saussure, 1878 ) and M. splendidulus Stål, 1877 by clearly more uniform colouration of pronotum and legs; and M. strigatipes Bolívar, 1913 from Mindanao by colouration of head and structure of the male genitalia.

Description. Male. Body small for genus, very similarly sized as M. pallidulus , dorsoventrally compressed ( Figs. 3A, 3B ). Head slightly raised in posterior half behind eyes, flattened between eyes. Head rostrum 1.6 times as wide as scapus, 0.9 times as wide as eyes, with apex truncated (in dorsal view) ( Figs. 3A, 3C ). Scapus elongated. Eyes distinctly vertically oblong, barely projected laterally ( Fig. 3B ); median and lateral ocelli very oblong, positioned behind antennal scapus; median ocellus distinctly wider than long and located very slightly before lateral ocelli; lateral ocellus more bean-shaped, located between scapus and anterior margin of eye ( Fig. 3C ). Maxillary palpi fairly stout, with apical (fifth) segment elongated, slightly more swollen, obliquely triangular (but its apex truncated) but shorter than third and subapical (fourth) segments ( Fig. 3D ). Posterior of eye above gena finely pubescent. Pronotal disc 0.6 times as long as wide, trapezoidal ( Fig. 3A ). Pronotal lateral lobe 1.2 times as long as tall, finely pubescent and margin with longer and thicker setae ( Fig. 3D ). Fore tibia with large and swollen conchate inner tympanum and large oval and open outer tympanum ( Fig. 3E ); fore and middle legs generally finely pubescent, with a few stout setae located usually along ventral margin; without subapical spines on ventral margins.

Male. Tegmen extending beyond abdominal apex; dorsal field barely longer than lateral field; mirror large, 2.2 times as long than wide, diamond-shaped with anterior and posterior parts narrowly angular, separated by a transverse vein in middle ( Fig. 3A ); with five harp veins ( Fig. 3A ); Sc with seven branches ( Fig. 3B ). Hind wings surpassing tegmen. Abdominal gland with posterior margin of fifth segment rectangularly, emarginated in middle, tubercle on sixth segment with anterior apex triangular and apex ( Figs. 4A, 4B ). Anal plate strongly and narrowly excised in middle, lateral of excision with dense strong setae pointing posteriorly; with a dorsal oval plate slightly surpassing lateral lobes, with posterior margin somewhat truncated ( Fig. 4C ). Male genitalia as shown in Figs. 4 D–4F: epiphallus (ep) elongated, tapering slightly posteriorly, at posterior end excised deeply and broadly with two strongly sclerotized apical epiphallic processes (ep.p) produced at base of excision, pointing externally; apical epiphallic process large, extending beyond lateral margin of epiphallus, curved anteriorly at apex into a hook-like acute apex. Ectoparameres (ecp) producing slightly beyond apex of epiphallus, slender, slightly curved with apex subacute. Rachis (= guiding rod) with apical process (p.ra) produced well beyond apex of epiphallus, enlarged at apex, with a dorsal lobe bent anteriorly. Formula (f) very slender and elongated, forked at posterior end. Mold of the spermatophore (m.sp) attachment plate with anterior end broadly rounded with two pyriform lateral lobes joined together by a narrow ‘bridge’ in the middle; sits at base of rachis. Endoparameral apodeme (ap) very long slender and straight, surpassing anterior end of formula. Rami slightly longer than epiphallus, slightly curved at anterior end.

Colouration. Head generally red brown, distinctly darker dorsally; scapus and pedicel red brown, darker dorsally; maxillary palpi and clypeus red brown, slightly darker at the apex. Pronotum also red brown but distinctly paler than dorsum of head. Tegmen pale yellow brown, unicolourous. Fore and middle legs generally red brown. Hind femur whitish, with three broad dark red brown bands, all with irregular margins, one at the base, one slightly behind middle (broadest) and one at the knee; hind tibia red brown. Tergites generally yellow brown, sternites generally pale whitish.

Measurements (in mm). Male holotype: BL = 11.0; PL = 1.6; PW = 2.5; TL = 10.1; HWT = 2.4.

Etymology. This species is named after the type locality, Laguna in Luzon; noun in apposition. This new species from Laguna differs from similar looking species from nearby regions Bataan or Bulacan and Batangas.

Figures

FIGURE 3. Mnesibulus laguna n. sp. male holotype: habitus in dorsal (A) and lateral (B) views, face in anterior view (C), head and pronotum in lateral view (D), anterior tympanum in anterior view (E). Scale bars: 2 mm (A, B), 1 mm (C–E).

FIGURE 4. Mnesibulus laguna n. sp. male holotype: metanotal gland in dorsal views (A, B), abdominal apex in dorsal view (C), genitalia in dorsal (D), ventral (E) and lateral (F) views. Scar bars: 1 mm (A–C).