Blackburnia (Metromenus) depressa (Sharp)

Liebherr, James K., 2009, Native And Alien Carabidae (Coleoptera) Share Lanai, An Ecologically Devastated Island, The Coleopterists Bulletin 63 (4), pp. 383-411 : 399

Blackburnia (Metromenus) depressa (Sharp)

Distribution. This species is known from various localities ( Fig. 6B ) within the cloud forest and mesic forest communities ( Fig. 1 ). The only known locality within the mesic forest zone is in Kaiholena Gulch, where specimens of this species were collected by Perkins (1894) at approximately 600 m el. (lots ‘‘78. Lanai, behind Koele II. ’94,’’ and ‘‘86. Lanai, above 2000 ft. I. ’94’’; Anonymous N. D.). Records from 1987 to the present are restricted to habitats 750–1,030 m elevation within the cloud forest community.

Habitat. This species is recorded from arboreal microhabitats, most often involving the beetles lodging between plant surfaces. These include between the appressed leaf axils of Freycinetia arborea Gaudichaux-Beaupre´, within the dead stipes of Sadleria ferns, and on the ground under rotting Pritchardia palm fronds. The beetles can be found also on vegetation at night, including on the fronds of Cibotium tree ferns and uluhe fern. Collections of this species have been made predominantly in association with the native species B. filipes , M. filipes , M. flavipes , and B. ignicola . As mentioned above under M. filipes , B. depressa was collected along with the non-native M. buchanani while beating banks of uluhe fern, and with G. picipes by beating soft understory ferns.

Figures

Fig. 6. Known distributions of carabid beetle species on Lanai. A. Blackburnia lanaihalensis. B. B. depressa. C. B. filipes. D. Metacolpodes buchanani. E. Gnathaphanus picipes (small circles), G. picipes plus G. multipunctatus (larger bullseye). F. Perigona nigriceps.

Fig. 1. Pre-Polynesian vegetation communities on the island of Lanai (after Hobdy 1993): 1) cloud forest; 2) mesic forest; 3) dry forest; 4) arid grassland and shrubland; 5) coast and strand.