Mecyclothorax sedlaceki Darlington, 1971

Liebherr, James K., 2017, Review of Mecyclothorax Sharp (Coleoptera: Carabidae: Moriomorphini) from Papua New Guinea, with Descriptions of Five New Species, The Coleopterists Bulletin 71 (4), pp. 679-703 : 697

10. Mecyclothorax sedlaceki Darlington, 1971 ( Figs. 7 , 28 , 32 )

Mecyclothorax sedlaceki Darlington 1971: 265 ; Baehr 1995: 4–5, 2002: 702, 2008: 137, 2014: 126.

Diagnosis. This dark-bodied species with quadrisetose pronotum is the only Papua New Guinea species to lack the parascutellar seta in all individuals. The fuscous character of the beetles is compounded by the well-developed isodiametric microsculpture on the elytra enhancing the somber coloration. The third antennomere is apically setose as in the glossy M. kavanaughi and M. kubor , although M. sedlaceki differs also in the presence of two dorsal elytral setae in the third interval, as opposed to the elevated number of 3–5 in the other two species. The very different male aedeagal configurations of the three species ( Liebherr 2008, fig. 4; Baehr 2008, figs. 1–2) suggest that the shared antennal setation is not a synapomorphy. Standardized body length is 4.4–4.8 mm (three females including holotype).

Female Reproductive Tract. Bursa copulatrix columnar ( Fig. 28 ), length slightly over 2X maximal breadth (compressed under microslide cover slip); spermathecal duct entering bursa dorsobasally, anatomically opposite ventrobasal juncture of common oviduct and bursal base (sometimes differentiated as the vagina); spermathecal duct elongate, narrow, over 4X length of fusiform spermathecal reservoir; spermathecal gland duct entering at base of spermathecal reservoir; basal gonocoxite 1 with 2 apical fringe setae, several small setae along the medial surface; apical gonocoxite 2 broad basally due to laterally extended apodeme (as in Fig. 31 ), with 2 gracile lateral ensiform setae, 1 similarly shaped dorsal ensiform seta, 2 apical nematiform setae in fossa, situated 0.20–0.25X gonocoxite length from the apex.

Distribution and Habitat. This species is known from elevations ranging 3,200 –4,500 m on Mt. Wilhelm ( Fig. 32 ). Previously reported elevations include 3,200 m, 3,750 m, 3,900 m, and 4,250 m (type locality in Darlington 1971 and Baehr 2008). To these can be added collections from Lake Piundi at 3,480 m (25.x.1975, P. Beron, NMNHS) and the summit at 4,500 m (6.viii.1969, J. L. Gressitt, BPBM). All collections of this species comprise singleton specimens. This transect includes the main hiking trail that approaches the summit from the southeast, passing the acclimatization hut at 3,600 m ( Google Earth 2017). Above 3,800 m, all M. sedlaceki localities are in open alpine to aeolian habitat.

Figures

Figs. 5–8. Mecyclothorax species, dorsal habitus. 5) M. brispex; 6) M. gressitti; 7) M. sedlaceki; 8) M. amingwiwae. Range of standardized body lengths (in mm) and setal formulae (see text) for number of supraorbital setae each side, number of pronotal setae each side, number of dorsal elytral setae each elytron, and number of setae at the apex of each elytron are indicated.

Figs. 25–28. Mecyclothorax species, female gonocoxae, laterotergites VIII, and internal reproductive tract, ventral view. 25) M. andersoni; 26) M. brispex; 27) M. gressitti; 28) M. sedlaceki. Abbreviations are defined in Table 1; position of spermathecal duct dorsad bursa indicated by dashed lines; scale bars = 0.25 mm.

Fig. 32. Localities in Papua New Guinea from which Mecyclothorax spp. were collected and the particular species collected at each locality. 1 = Mt. Capella — M. baehri; 2 = Mt. Fugilil — M. brispex and M. medioconstrictus; 3 = Kubor Range — M. kubor; 4 = Mt. Wilhelm — M. sedlaceki; 5 = Finisterre Range — M. kavanaughi; 6 = Mt. Missim — M. gressitti; 7 = Mt. Kaindi, Edie Creek and Bulldog Road — M. andersoni, M. cuccodoroi, and M. loebli; 8 = Mt. Amungwiwa—M. amingwiwae.

Figs. 29–31. Mecyclothorax species, female gonocoxae, right side, ventral view. 29) M. andersoni; 30) M. brispex; 31) M. gressitti. Abbreviations aredefined in Table 1; scale bars = 0.05 mm.