Zeadalmodes myrmecophilus 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

Zeadalmodes myrmecophilus Nomura and Leschen , new species

( Figs. 12A , 13–15 )

Description. Male. Body length 2.84–3.18 mm, width 0.82–0.86 mm, elongate, thick, cylindrical ( Fig. 12A ). Head about as long as wide, nearly trapezoidal, clypeus very short, arcuate on anterior margin; frons weakly concave; vertex gently convex, with pair of distinct, round dorsal tentorial pits and very short median longitudinal carina just before occipital constriction; postgenae large, rounded, weakly convex on ventral side, sparsely covered with long, suberect setae ( Fig. 13A, B ). Eyes small, hemispherical, composed of 25–30 facets. Antennae 0.92–0.94 mm in length, short and thick, relative length (width) of each antennomere from base to apex to width of antennomere I: 0.8 (1.0); 1.0 (0.8); 0.8 (0.8); 0.8 (0.8); 0.8 (0.8); 0.7 (0.8); 0.7 (0.8); 0.7 (0.8); 0.9 (0.9); 0.9 (1.1); 2.5 (1.3). Maxillary palpi short, each elongate, reaching antennomere IV in ventral view; palpomere I very short; II elongate, thickened distally; III short; IV largest, about as long as I + II + III, elongate, nearly cylindrical in basal half, widest at apical 2/3, narrowed distally; palpal spine short.

Pronotum wider than head, nearly circular in dorsal view, slightly convex dorsally, uniformly covered with minute punctures and pubescence on dorsal surface, with pair of large, round lateral foveae at basal 1/3, shallow median longitudinal sulcus, and pair of transverse sulci connecting lateral foveae ( Fig. 13A ). Metaventrite large, weakly convex, densely covered with minute pubescence on ventral surface ( Fig. 13E ). Elytra about as long as wide, nearly trapezoidal, gently convex, each elytron with 2 faint basal foveae, weak humeral denticle, and 2 longitudinal sulci; adsutural sulcus running from inner basal fovea to apex of elytron; outer sulcus from outer fovea to near middle ( Fig. 13F ). Legs short and elongate.

Abdomen longer than elytra, elongate, subcylindrical ( Fig. 13G, H ); sternite III very short, transverse, with ventromedian tubercle between hind coxae; IV largest, quadrangular dorsally, with pair of narrow and parallel-sided paratergites on lateral sides and very small shallow basimedian depression just behind elytra; V almost equal size to IV; VI slightly shorter and narrower than V; VII shorter than VI, rounded posteriorly; tergite VIII transverse, rounded posteriorly, densely setose on dorsal surface, with pair of small depressions basolaterally ( Fig. 14A ); sternite VIII transverse, slightly smaller than tergite VIII, densely setose ventrally, shallowly emarginate on posterior margin ( Fig. 14B ); tergite IX divided into pair of triangular sclerites connected to each other ventromedially, sclerites longer than wide, with dense setae apically; sternite IX located between sclerites of tergite IX, about as long as tergite IX, oblong, densely setose on apical 1/2 ( Fig. 14C ).

Male genitalia thickened basally, median lobe bulbous basally, with sharpened basal spine at base of basal orifice, asymmetrical in apical part, with broad, rounded right spine, very narrow, acute median spine, and narrow, weakly incurved left spine ( Fig. 14D, E ).

Female. Body length 2.98–3.08 mm, width 0.84–0.90 mm, antennal length 0.84–0.98 mm. Very similar to male, almost unseparable externally, but mid-leg slenderer than that of male, relative length (width) of each antennomere from base to apex to width of antennomere I: 0.9 (1.0); 1.1 (0.9); 0.9 (0.7); 0.7 (0.7); 0.8 (0.8); 0.7 (0.8); 0.8 (0.8); 0.8 (0.9); 0.9 (1.0); 1.0 (1.2); 2.5 (1.4). Abdominal tergite VIII transverse, simply narrowed posteriorly; sternite VIII transverse, slightly wider than tergite VIII; sternite IX nearly triangular, narrowed posteriorly, weakly emarginate in posteromedian part; genital plate small and triangular ( Fig. 15C ).

Remarks. This new species is distinct by having a comparatively large, elongate, and stout body, the nearly circular pronotum, and the narrow and subcylindrical abdomen. One female specimen collected from Waiohine Gorge (WN) is smaller and lighter colored than typical Z. myrmecophilus and may represent a separate species. It was, therefore, excluded from the type series.

Distribution. North Island. Coromandel (CL), Bay of Plenty (BP), Hawkes Bay (HB), Rangitikei (RI), Wellington (WN).

Host Ants. A u s t ro p o n e r a c a s t a n e a a n d Austroponera castaneicolor (Dalla Torre) (Ponerinae) .

Specimens Examined. Holotype, male (card mounted with genitalia on separate acetate label), New Zealand WN Karori Reservoir 8. i. 1995 // In decayed Nothofagus wood // HOLO- TYPE Staphylinidae Staphylinidae , Pselaphinae Zeadalmodes myrmecophilus Nomura et Leschen S. Nomura det., 2013 [red label]. Paratypes: CL: 1 female, Mt. Moehau, 600m, (in Mesoponera castanea nest [= Austroponera castanea ]), 18. ii. 1978, B. A. Holloway leg.; 1 male, 1 female, Coromandel Ra., 600m, 12 km E of Tapu (nest of Mesoponera castanea [= Austroponera castanea ], 79/3), 18. i. 1979, A. W. Don leg. 1 male, Wards Bush, N of Te Hope Str. (x Mesoponera castanea nest [= Austroponera castanea ]), 2. xi. 1979, B. A. Holloway leg; 1 male, 1 female, Square Kauri Tk (ant nest [the host ant was not vouchered]), Coromandel Rng., 3. xi. 2005, S. Nomura leg. BP: 1 female, Motu River, Bay of Plenty, North Is. (from ant nests), June, 1928, A. E. Brookes leg., A. E. Brookes Collection, N. gen. et sp. Dalma- Dalmisus group, det. E. S. Gourley 2. ix. 1964. HB: 1 female, Tangoio, White Pine Bush Res. (sifted woodmould 83/147), 24. xii. 1983, J. C. Watt leg; 1 female [no collecting data]. WN/RI: 1 female, Manawatu Gorge, Woodville Rng., 31. viii. 1987; 1 female, same locality as above, but 13. i. 1990 [J.T. Nunn; Austroponera castanea ]. WN: 1 male, Khandallah Domain, 9. xii. 1992; 1 male, Wilton Bush (ant: Mesoponera [= Austroponera castanea ]), Wellington, 7. ii. 1987, J. T. Nunn leg.; 1 female, same locality as above (in ants’ nest, associated ants [ Austroponera castanea ]), Wellington, 7. xi. 1995; 1 female, Tinakori Hill, Wellington (ant: Mesoponera [= Austroponera castaneicolor ]), 2. iii. 1987, J. T. Nunn leg.; 1 male, same locality as above, but 15. v. 1987 (ant: Mesoponera [= Austroponera castanea ]); 1 male, 1 female, A’ Deans Bush, Waipukurau, 31. iii. 1991 [J.T. Nunn; Austroponera castanea ]; 1 male, 1 female, Tinakori Hill, Wellington, 8. v. 1991 [J.T. Nunn; Austroponera castanea ]; 1 female, same locality as above (in decayed wood), 19. vii. 1991 [J.T. Nunn]; 1 male, same locality as above (in ants’ nest [ Austroponera castanea ]), 30. viii. 1991 [J.T. Nunn]; 1 female, same locality as above (ant: Mesoponera [= Austroponera ]) (with Mesoponera ants), 27. x. 1991 [J.T. Nunn]; 1 male, Lower Hut (in ants’ nest), Woburn Res., 10. ix. 1994 [J.T. Nunn]; 2 females, Keith George Res., Silverstream, (in ants’ nest, associated ants [ Austroponera castanea ]), 22. xi. 1995 [J.T. Nunn].

Figures

Fig. 12. Zeadalmodes species, habitus. A) Z. myrmecophilus, male holotype, B) Z. brevis, female paratype. Scale = 1 mm.

Fig. 13. Zeadalmodes myrmecophilus, male. A) Head and prothorax, dorsal view, B) Head and prothorax, in ventral view, C) Right maxillary palpus, ventral view, D) Right antenna, ventral view, E) Meso- and metathoraces, ventral view, F) Left elytron, dorsal view, G) Abdomen, dorsal view, H) Abdomen, ventral view.

Fig. 14. Zeadalmodes myrmecophilus, male. A) Tergite VIII, B) Sternite VIII, C) Tergite IX (two lateral plates) and sternite IX (middle plate), D) Genitalia, ventral view, E) Genitalia, lateral view. Scale = 0.1 mm.

Fig. 15. Zeadalmodes myrmecophilus, female. A) Tergite VIII, B) Sternite VIII, C) Genital plate in ventral view. Scale = 0.1 mm.