Mecyclothorax ballioides Perrault, 1978b: 151; 1988: 240

Liebherr, James K., 2013, The Mecyclothorax beetles (Coleoptera, Carabidae, Moriomorphini) of Tahiti, Society Islands, ZooKeys 322, pp. 1-170 : 39-40

27. Mecyclothorax ballioides Perrault, 1978b: 151; 1988: 240

Identification.

Beetles of this species are similar to those of Mecyclothorax bryobioides (Fig. 20D), however the pronotum is less constricted basally - MPW/BPW = 1.60-1.73 (n = 5) - and the elytra are more broadly ovoid (Fig. 21B). The pronotal hind angles are sharply obtuse, with the pronotal lateral margins subparallel to convergent immediately anterad the angles. The pronotal margin is beaded both laterad and basad the hind angle, the bead broadest immediately inside the hind angle. The discal elytral striae are shallow and distinctly punctate basally, the punctures appearing isolated due to the shallow depth of the striae. The frons and vertex are glossy with indistinct transverse wrinkles. The pronotal disc bears indistinct transverse-mesh microsculpture, the sculpticell margins not visible in areas of reflected light, and the discal elytral intervals bear a distinct mesh composed of both isodiametric and transverse sculpticells, the sculpticells arranged in irregular transverse rows. The male aedeagal median lobe has an evenly arcuate shaft and a short apex with an abrupt ventral extension that has a tightly rounded tip (Fig. 19F). Setal formula 2121; standardized body size 4.0-4.4 mm.

Distribution and habitat.

This species has been collected from 1125-1490 m elevation on Mont Marau, always in association with ferns. These situations include beating dead Cyathea tree fern fronds, or collection onto sheets via application of pyrethrin fog to banks of dead or living low-stature ferns.