Mexico borneensis, Yoshitomi, 2019

Yoshitomi, Hiroyuki, 2019, Review of the Asian Thaumastodinae (Coleoptera, Byrrhoidea, Limnichidae), with a phylogeny of the genera, European Journal of Taxonomy 583, pp. 1-45 : 30-32

Mexico borneensis sp. nov.

urn:lsid:zoobank.org:act:C119FDE3-9A59-4A07-A77A-AF4C067C5D1B

Figs 11A , 16

Etymology

This species is named after its type locality.

Material examined

Holotype MALAYSIA • ♂; “BRITISH N BORNEO Labuan Island Nov. 28–29, 1958 ”; “Intertidal Zone”; “ L. W. Quate Collector ”; BPBM.

Paratypes MALAYSIA • 1 ♀; same collection data as for holotype; BPBM • 1 ♂, 1 ex.; “BRITISH N BORNEO Labuan Island Nov. 28–29, 1959 ”; “ Intertidal Zone ”; “ Maa Collector ”; BPBM .

Description

Male

BODY. Oval, slightly convex dorsally, shiny, closely covered with suberect golden setae. Coloration of body black; elytra with small, irregular silver spots consisting of erect setae.

HEAD. Finely punctate, slightly convex on dorsum between eyes; distance between eyes about 0.8 times as long as eye diameter in dorsal view.

ANTENNAE. Short, reaching about anterior third of pronotum.

PRONOTUM. Closely punctate; lateral margins gently arcuate; PW/ PL 2.04–2.30 (2.20). Scutellum small, square.

ELYTRA. Oval, widest at base, gently tapered posteriorly; caudal quarter of lateral margins slightly and minutely serrate; EL/ EW 1.33–1.48 (1.38); EL/ PL 3.11–3.70 (3.35); EW/ PW 1.09–1.14 (1.11); TL/ EW 1.73–1.88 (1.79).

ABDOMEN. Sternite VII ( Fig. 16A ) with two pairs of long and stout extra setae, bearing about 20 long setae, bifid in postero-lateral corners, gently projecting triangularly in median part of caudal margin. Sternite VIII ( Fig. 16B ) small, slightly sclerotized, Y-shaped. Sternite IX ( Fig. 16C ) well sclerotized, lightly curved in basal part; apical plates long and stout, pointed at apices.

AEDEAGUS ( Fig. 16 D–F). Long and slender, almost symmetrical; basal piece oval; lateral lobes short, with 4 apical setae; median lobe long and slender, subparallel-sided near base to near apex, finely punctuate, with nipple-like apex; ventral plates long and slender, reaching about apical tenth of median lobe, mostly fused to median lobe; ML/ BL 2.36; ML/ LL 2.57.

Female

Sexual dimorphism slight. Sternite VII ( Fig. 16G ) similar to that of male, but lacking extra setae. Urosternite ( Fig. 16H ) well sclerotized, T-shaped, with long and slender apodeme. Ovipositor ( Fig. 16I ) well sclerotized; coxite sparsely punctuate, obtuse at apices; apex of baculus bifid; approximate ratio of coxite and baculus (n = 1) 1.0: 5.5.

Measurements

Unsexed (n = 3): TL 1.70–1.88 (1.81) mm; PW 0.90–0.92 (0.91) mm; PL 0.40–0.45 (0.42) mm; EL 1.30– 1.48 (1.39) mm; EW 0.98–1.05 (1.01) mm.

Distribution

Malaysia (Labuan Island, off Borneo).

Remarks

This species is similar to M. baliensis sp. nov. in the shape of the aedeagus, but differs from it in the following characteristics: median lobe pointed at apex (obtuse in M. baliensis sp. nov.) and lateral lobes bearing 4 apical setae (3 in M. baliensis sp. nov.).

Figures

Fig. 11. Species of Mexico Spilman, 1972. A. M. borneensis sp. nov., holotype (BPBM). B. M. papuanus sp. nov., holotype (BPBM). C. M. ogasawaraensis sp. nov., holotype (EUMJ). D. M. baliensis sp. nov., holotype (EUMJ). E. M. palauensis sp. nov., holotype (EUMJ). F. M. masamii (Satô, 1994) (EUMJ). G. M. taiwanus (Satô, 1994), paratype (EUMJ). Scale bars: 1.0 mm.

Fig. 16. Mexico borneensis sp. nov., male (A–F) and female (G–I) genitalia (holotype and paratype, BPBM). A, G. Sternite VII. B. Sternite VIII. C. Sternite IX. D. Aedeagus, ventral view. E. Aedeagus in dorsal view. F. Aedeagus in right lateral view. H. Urosternite. I. Ovipositor.