Mecyclothorax simpulum, Liebherr, James K., 2015

Liebherr, James K., 2015, The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini) of Haleakala-, Maui: Keystone of a hyperdiverse Hawaiian radiation, ZooKeys 544, pp. 1-407 : 217-221

Taxon classification Animalia Coleoptera Carabidae

(090) Mecyclothorax simpulum sp. n. Figs 104F, 105F, 110C, 112, 113 E–G

Diagnosis.

This species (Fig. 110C) can be easily diagnosed from the other two in this triplet- Mecyclothorax bacrionis (Fig. 110A) and Mecyclothorax haleakalae (Fig. 110B) by the presence of both anterior and posterior supraorbital setae (in 1 of 22 specimens, the anterior supraorbital setae is unilaterally absent; setal formula 2(1) 0 2 0). The pronotum of this species is of exceedingly similar to that of Mecyclothorax haleakalae , however there are fewer punctures on the median base; ~25 each side. The sutural stria is shallower also, though discal stria 2 is about as impressed as in individuals of Mecyclothorax haleakalae . The male aedeagal median lobe has a slightly narrower apex, assessed dorsoventrally, with a more rounded tip (Fig. 113E, G) versus the dorsoventrally broader, apically flattened median lobe apex of Mecyclothorax haleakalae males (Fig. 113A, C–D). The male aedeagal internal sac also lacks any discrete ventral ostial microtrichial patches (Fig. 113G), though a dorsal ostial microtichial patch is present. Standardized body length 5.3-6.3 mm.

Description

(n = 5). [The above description of Mecyclothorax bacrionis can serve to describe this species with the following substitutions.] Eyes large and convex, ocular ratio = 1.51-1.61, ocular lobe ratio = 0.84-0.91. Pronotum appearing elongate, but MPW/PL = 1.11-1.12, basally constricted, MPW/BPW = 1.59-1.72; hind angles slightly obtuse, apex sharp, projected; basal margin slightly convex between laterobasal de pressions, margins posterad laterobasal depressions separately convex; anterior callosity slightly convex, crossed by dense though indistinct longitudinal wrinkles; pronotal apical width variably subequal to greater than basal width, APW/BPW = 1.01-1.14, laterobasal depression narrow, surface punctate, continuous with lateral depression. Elytra narrowly ovoid but humeral angles situated posterolaterad pronotal hind angles, therefore MEW/HuW = 2.19-2.38 (values marginally less than those recorded for Mecyclothorax bacrionis ); discal striae 1-2 impressed, punctate, the punctures more closely spaced on sutural stria; striae 3-5 punctate but less impressed than inner striae, punctures therefore more isolated; 2 dorsal elytral setae at 0.22 –0.27× and 0.66 –0.69× elytral length. Mesepisternum with ~11 punctures in 2-3 rows. Microsculpture of vertex an indistinct transverse mesh, sculpticell breadth 2 –3× length, surface glossy in parts; pronotal disc with indistinct transverse lines on a glossy surface, median base glossy medially, indistinct transverse sculpticells laterally; elytral disc with very small, indistinct isodiametric sculpticells in partially transverse rows, apex with shallow isodiametric mesh in transverse rows. Coloration of elytral disc rufopiceous, but without cupreous reflection associated with glossy elytral surface of Mecyclothorax bacrionis .

Male genitalia (n = 5). Aedeagal median lobe robust, distance from parameral articulation to tip 3.2 × depth at midlength (Fig. 113E, G); apex narrowly extended 2 –3× its depth beyond ostial opening, tip slightly oblique, dorsoapical face flattened, tip slightly expanded ventrally; median lobe parallel sided along shaft, right margin broadly concave before slightly offset parallel-sided apex with blunt tip (Fig. 113F); internal sac with transverse dorsal ostial microtrichial patch at base of right side (Fig. 113G), ventral surface covered with shaggy pelage of long microtrichia; flagellar plate large, robust, length 0.56 × parameral articulation-tip distance.

Female reproductive tract (n = 1). Bursa copulatrix columnar with a rounded apical expansion, length 1.6 mm, apical lobe width 0.72 mm, basal constriction at vagina 0.36 mm broad (Fig. 104F); bursal walls translucent, thickly wrinkled; gonocoxite 1 with 5-6 apical fringe setae, 1-2 thick setae at medioapical angle and 12-14 smaller setae along medial surface (Fig. 105F); gonocoxite 2 subacuminate, lateral extension at base with curved terminus, 2 lateral ensiform setae, apical nematiform setae on medioventral surface at 0.75 × gonocoxite length.

Holotype.

Male (CUIC) labeled: HI: Maui Haleakala N.P. / Kaupo Gap el. 1736 m / N20°42'27", W156°08'41" / 17-V-2001 lot 01 pyr. fog / Acacia koa J.K. Liebherr // HOLOTYPE / Mecyclothorax / simpulum / Liebherr / det. J.K. Liebherr 2015 (black-margined red label).

Paratypes.

HI: Maui: Haleakala N.P., Kaupo Gap, pyrethrin fog Acacia koa , 1736 m el., 17-v-2001 lot 01, Liebherr (CUIC, 22); Kipahulu Vy., Central Pali Tr., sift leaf/moss litter, 915 m el., 30-iv-1991 lot 03, Liebherr/Medeiros (CUIC, 1).

Etymology.

As in Mecyclothorax bacrionis , the conformation of the male aedeagal median lobe is the most reliable means to diagnose this species. Here the Latin simpulum , small ladle, is used as a noun in apposition to signify the shape of the male median lobe (Figs 113E, G).

Distribution and habitat.

Mecyclothorax simpulum is a species of koa forests in eastern Haleakalā, found in lower Kīpahulu Valley (915 m el.) and in Kaupō Gap at 1736 m elevation (Fig. 112). The Kīpahulu record was from sifted moss and leaf litter from under large koas, and the Kaupō Gap record was based on application of pyrethrin fog to the trunk of a large koa .