Kenocoelus johni Nomura and Leschen, 2015

Nomura, Shûhei & Leschen, Richard A. B., 2015, Myrmecophilous Pselaphinae (Coleoptera: Staphylinidae) from New Zealand, The Coleopterists Bulletin 69 (1), pp. 121-152 : 121-152

Kenocoelus johni Nomura and Leschen , new species

( Figs. 1C, F , 2C, F, I, L , 3C, F, I, L )

Description. Male. Body length 1.46–1.60 mm, width 0.50–0.58 mm, small-sized, elongate, reddish brown, shiny. Head wider than long, nearly trapezoid in dorsal view, almost smooth, sparsely covered with minute pubescence on dorsal surface; clypeus very short; frons almost flat; vertex weakly convex; dorsal tentorial pits indistinct; postgenae short, rounded, covered with short, suberect setae posterolaterally. Eyes small, ovoid, each composed of 10–15 facets. Antennae short, elongate, length 0.55–0.62 mm, reaching hind margin of pronotum, relative length (width) of each antennomere from base to apex to width of antennomere I: 0.6 (1.0); 0.9 (0.9); 0.8 (0.8); 0.8 (0.8); 0.9 (0.9); 0.9 (0.9); 1.0 (1.0); 1.0 (1.0); 1.2 (1.2); 1.2 (1.3); 2.2 (1.5). Maxillary palpi short, elongate; palpomere IV largest, nearly fusiform.

Pronotum slightly longer than wide, rounded laterally, almost smooth, sparsely covered with minute punctures dorsally, with pair of lateral foveae and shallow transverse depression at basal 1/3. Prosternum almost flat in anteromedian part, sparsely covered with pubescence, without median carina just before fore coxae. Metaventrite large, gently convex, densely covered with pubescence ventrolaterally. Elytra slightly longer than pronotum, flattened on dorsal side, each elytron with 2 basal foveae and complete adsutural sulcus. Hind wings developed or reduced (dimorphic). Legs short and slender; mid-tibiae short, almost straight, weakly angulate on inner side at apex.

Abdomen slightly longer than elytra, elongate, gently narrowed posteriad; segment IV largest, transverse, slightly broadened posteriorly, with pair of narrow and parallel-sided paratergites; V about as long as IV, narrower than IV, with pair of narrow paratergites in lateral parts, with 2 pairs of very large concavities on ventral side; VI shorter than V, transverse, with pair of narrow paratergites; VII shorter than VI, transverse, with pair of very small, triangular paratergites; tergite VIII transverse, arcuate on posterior margin; sternite VIII transverse, shortest at middle, rounded laterally; tergite IX very small, paired, asymmetrical; sternite IX very small, ovoid.

Male genitalia small, very weakly sclerotized; median lobe slender, thickened near middle; basal orifice nearly triangular, strongly projecting basad; parameres paired, very short and slender, narrowed posteriorly ( Fig. 3L ).

Female. Body length 1.56–1.64 mm, width 0.48–0.55 mm, antennal length 0.50–0.59 mm, similar to male but differs in the following points: eyes reduced, each composed of about 4 facets; elytra shorter and narrower than in male; abdomen longer than elytra; hind wings vestigial, flightless; sternites IV–V without concavity and projection.

Remarks. This species is most closely allied to K. mikonuiensis in having a median apodeme within each concavity on sternite V in the male. However, it is separated by the semicircular concavity lacking a projection at the center of male sternite IV.

Host Ant. Huberia striata (Smith) (Myrmecinae) .

Etymology. This new species is dedicated to Mr. John Nunn in recognition of his contributions to the study of New Zealand Coleoptera .

Distribution. North Island. Auckland (AK), Waikato (WO), Bay of Plenty (BP), Wellington (WN).

Specimens Examined. Holotype, male, Waitakere Ra, Kauri Park (under rotting Punga in bush, ants nest) 80/127 [AK], 6. xii. 1980, A. W. Don. leg. // HOLOTYPE Staphylinidae Pselaphinae Kenocoelus johni Nomura et Leschen, 2014 S. Nomura det., 2014 [red label]. Paratypes: AK: 3 males, 3 females, same data as holotype. WO: 2 males, Herangi Ra (litter), 500m, above Mangatoa Saddle 82/136, 9. xii. 1982, J. S. Dugdale leg. BP: 1 male, Mt. Te Aroha Smt (Moss), 1000m, 77/135, 3. xi. 1977, B. M. May leg.; 1 male, Motu River, Bay of Plenty, N. Island, from ants nests, June, 1928, A. E. Brookes leg., A. E. Brookes Collection, Huberia striata , det. D. Ward 2013; 6 males, 13 females, Waioeka Gorge (from ant nest of Huberia striata (F. Smith)) , New Zealand, 20. iv. 1987, J. T. Nunn leg.; 4 females, same data as above, but 18. iv. 1987. WN: 2 females, Cross Creek, 27. ii. 1993, W. L. Wairarapa leg.; 1 male, Kelly’ s Tck (In ants’ nest, associated ant), Rimutaka Rng, 5. xi. 1995 [J. T. Nunn].

Figures

Fig. 1. Kenocoelus species, habitus. A) K. dimorphus, male, B) K. mikonuiensis, male, C) K. johni, male, D) K. dimorphus, female, E) K. mikonuiensis, female, F) K. johni, female. Scale bar = 1 mm.

Fig. 2. Kenocoelus species. A) K. dimorphus, ventral view, B) K. mikonuiensis, ventral view, C) K. johni, ventral view, D) K. dimorphus, abdominal sternites IV–V, ventral view, E) K. mikonuiensis, abdominal sternites IV–V, ventral view, F) K. johni, abdominal sternites IV–V, ventral view, G and J) K. dimorphus, left concavities on abdominal sternites IV–V, H and K) K. mikonuiensis, left concavities on abdominal sternites IV–V, I and L) K. johni, left concavities on abdominal sternites IV–V.

Fig. 3. Kenocoelus species. A) K. dimorphus, abdominal tergite VIII, B) K. mikonuiensis, abdominal tergite VIII, C) K. johni, abdominal tergite VIII, D) K. dimorphus, sternite VIII, E) K. mikonuiensis, sternite VIII, F) K. johni, sternite VIII, G) K. dimorphus, abdominal segment IX, H) K. mikonuiensis, abdominal segment IX, I) K. johni, abdominal segment IX, J) K. dimorphus, male genitalia, K) K. mikonuiensis, male genitalia, L) K. johni, male genitalia. Scale = 0.1 mm.