Fauna of NZ 45 - Landcare Research

24 Kuschel (2003): Nemonychidae, Belidae, Brentidae (Insecta: Coleoptera)
Rhicnobelus gen. nov.
Fig. 4, 5, 70–83
Type-species: Pachyura metallica Pascoe
Because of the close relationship with Pachyurinus, only
the main distinguishing characters of Rhicnobelus are here
given. Prothorax converging in gentle arc to an indistinct
apical constriction, with a fine groove on midline, lacking
impressions. Scutellum proclinate. Elytra with metallic
sheen, with transverse rugae at least near suture and no
depressions. Male tibiae mucronate. The vein A 1 is complete
in R. aenescens, interrupted in R. rubicundus, and
absent in R. metallicus. The inferolateral flange of elytra is
present in R. aenescens and R. rubicundus, absent in R.
metallicus.
Distribution. Endemic: North Island, South Island.
Host plant. Adults and larvae found so far associated only
with genera of Podocarpaceae and Phyllocladaceae.
Etymology. Rhicnóbelus (‘wrinkled dart’) from the Greek
rhiknós meaning wrinkled, and the weevil genus Belus
(meaning bullet or dart); gender masculine.
Key to species of Rhicnobelus
1 Club 5-segmented, by antennae having segment 7
distinctly wider than 6 and vestiture similar to that of
segment 8. Elytral rugae weak, usually confined to near
suture. Legs bright reddish brown contrastingly paler
than body. Length 4.5–6.5 mm. Northland to
Marlborough and Nelson ........ (p. 24) ... rubicundus
—Club 4-segmented, by antennae having segment 7 similar
to 6 in width and vestiture. Elytral rugae conspicuous,
extending to the sides. Legs as dark as remainder of
body ........................................................................ 2
2(1) Metasternal sides with large patch of dense, strikingly
white vestiture. Designs on elytra, when present,
directed obliquely forward from suture to sides, those
on middle of dorsum a V-shaped band. Length 4.5–7.5
mm. From Northland to Southland ..........................
.................................................. (p. 25) ... metallicus
—Metasternal sides lacking patch of dense white vestiture.
Designs on elytra, when present, directed obliquely
backward from suture to sides, those on middle of
dorsum jointly an inverted V-shaped band. Length 6.5–
8.9 mm. From Gisborne and Wanganui to Central Otago
and Dunedin .............................. (p. 26) ... aenescens
Rhicnobelus rubicundus (Broun) comb. nov.
Fig. 65–69; Map 6
Broun, 1880: 469 (Pachyura). —Waterhouse, 1883: 2, pl.
138, fig. 2 (Pachyura). —May, 1987: 45 (host plant);
1993: 39, fig. 208–218 (larva).
pilosus Broun, 1909: 137 (as var. of Pachyura rubicunda)
syn. nov
violaceus Broun, 1909: 137 (Pachyura). —Hudson, 1934:
147 (Pachyura) syn. nov.
Black or nearly so, with coppery, brassy or bluish, sometimes
iridescent sheen; antennae, legs and often tip of rostrum
bright reddish brown; apex of antennal segments and
last two tarsal segments usually darkened. Vestiture recumbent,
white throughout or in part, rather long, mostly
piliform, thicker, subsquamiform when condensed to dots
or oblique lines on dorsum, directed straight backwards.
Head conspicuously converging towards constriction,
densely punctate. Frons flat, lacking fovea. Prorostrum
less than twice as long as wide.
Prothorax 1.22–1.32x wider than long, converging in
gentle curve to indistinct collar, with an impression at base
followed by a fine sulcus; punctation dense, coarse, similar
to that of head, more or less aligned into transverse rows.
Scutellum in lateral view not or hardly higher than
pronotum, flat, transverse.
Elytra in lateral view slightly ascending for a short
distance behind base, parallel or slightly wider postmedially,
lacking depressions, evenly convex transversely on dorsum,
broadly rounded at apex; margin at apex distinctly asperate;
punctation dense, coarse, somewhat aligned transversely.
Wing venation as for P. sticticus (Fig. 49), A interrupted.
1
Femora very slender, showing hardly any swelling;
middle tibiae in male mucronate, finely denticulate near
mucro, slightly incurved; tarsi not obviously different in
the sexes. Ventrites 1–4 with bare patch on either side.
Tergites heavily pigmented, usually metallic blue.
Male: Tergite 8 as in Fig. 68, heavily pigmented,
separated by narrow membrane; sternite 8 as in Fig. 69,
shallowly emarginate. Tegmen and aedeagus largely in
agreement with P. sticticus (Fig. 61–63).
Female: Sternite 8 as in Fig. 65. Genitalia as in Fig. 66;
spermatheca as in Fig. 67.
Length: 4.5–6.7 mm.
Types. Pachyura rubicunda: described from 5 specimens
from Whangarei Heads. Lectotype % (here designated,
so as to assure correct and consistent application of
the name in the future), 6.1 x 2.0 mm, Manaia, Whangarei
Heads, 831, NZAC. Paralectotypes BMNH, NZAC.
Pachyura pilosa: described from one specimen. Holotype
&, 6.7 x 2.4 mm, Helensville, var. 831 [=rubicunda],
P.villosa [sic], T Broun, NZAC.