Mecyclothorax daptinus Sharp

Liebherr, James K., 2015, The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini) of Haleakala-, Maui: Keystone of a hyperdiverse Hawaiian radiation, ZooKeys 544, pp. 1-407 : 26-28

Taxon classification Animalia Coleoptera Carabidae

(004) Mecyclothorax daptinus Sharp Figs 15A, 16 A–B, 17A, 18A, 19

Mecyclothorax daptinus Sharp 1903: 249; Britton 1948b: 160.

Diagnosis.

This species is easily diagnosed by the pale pronotal and elytral margins contrasted with piceous discal areas and the rugose transverse wrinkles of the pronotal disc (Fig. 15A). The pronotum is moderately constricted basally–MPW /BPW = 1.44 –1.59– and the forebody dorsal surface bears well-developed microsculpture. The vertex is covered with upraised isodiametric sculpticells in transverse rows, and the pronotal disc is covered with a transverse mesh, sculpticell breadth 2 –3× length. Conversely, the elytral discal intervals are glossy, with a transverse mesh to transverse lines toward the lateral elytral margins. Setal formula 2 (1-2) 2 1[sae]; of the five individuals scored, two have both lateral and basal pronotal setae, and three have only the lateral pair of setae. Standardized body length 3.4-4.1 mm.

Identification

(n = 5). Beetles of this species are of stocky stature, with short, submoniliform antennal segments and short legs. The eyes are moderately convex, ocular ratio = 1.44-1.52, but they cover only the anterior portion of the protruded ocular lobes; ocular lobe ratio = 0.72-0.80. In addition to the transverse wrinkles on the pronotal disc, the deep anterior transverse impression and elevated and flat anterior callosity are crossed by dense longitudinal wrinkles. The elytra are subquadrate with tightly rounded humeral angles-MEW/HuW = 1.89-1.92-and the discal elytral intervals are convex, the associated striae 2-3 minutely punctate basally, striae 4-8 with only minute irregularities.

Male genitalia (n = 2). Aedeagal median lobe robust, short, distance from parameral articulation 2.8 × depth at midlength, apex briefly extended and evenly downturned beyond ostial opening (Fig. 16A); median lobe not curved to the right, though left side more broadly curved to rounded tip in ventral view (Fig. 16B); a moderate sized flagellar plate visible in uneverted specimen (Fig. 16B), no other sac ornamentation evident.

Female reproductive tract (n = 1). Bursa copulatrix basally broad, apically digitiform, overall length 0.43 mm, basal breadth 0.30 mm, apical lobe breadth 0.11 mm (Fig. 17A); bursal walls membranous, thin, transparent; gonocoxite 1 with 2 apical fringe setae, medial seta smaller, 1-2 small setae on medial surface (Fig. 18A); gonocoxite 2 subtriangular, apex subacuminate, base evenly extended from curved lateral surface, with 2 lateral ensiform setae, apical seta broader and longer, apical nematiform setae on medioventral surface at 0.71 × gonocoxite length.

Lectotype.

Female (BMNH) hereby designated, labeled: Mecyclothorax daptinus Type D.S. Haleakala Perkins 113 (on mounting platen) // Type // Hawaiian Is. Perkins 1904-336 // Haleakala Maui 5000 ft. Perkins IV 1894 // LECTOTYPE Mecyclothorax daptinus Sharp J.K. Liebherr 1998 (black-margined red label).

Distribution and habitat.

Mecyclothorax daptinus is distributed along the leeward edge of the Waikamoi forest (Fig. 19), with the only recent records resulting from the application of pyrethrin fog to a mossy koa trunk or a mossy ‘ōhi‘a log. All but one of the collections have come from mesic forest near the Ukulele Camp site-~1500 m elevation-with the exception being a site on the Kula Pipeline Road at 1300 m elevation.