Fauna of NZ 45 - Landcare Research

Fauna of New Zealand 45 35
Prothorax longer than wide, strongly constricted at
basal one-third to an unrimmed broad collar, truncate,
without trace of an apical constriction, its axial and tangential
convexity pronounced, in profile weakly proclinate, only
1.4x longer dorsally than ventrally; notum lacking
impressions. Scutellum concealed.
Elytra broadly elliptical, inflated, lacking humeral callus,
jointly rounded to a rather narrow apex, vertical at base, in
profile highly humped, strongly, uniformly convex. Striae
totally erased on upper surface, but striae conspicuous on
underside, here showing nearly as wide as interstriae, also
stria 10 visible at posterior end; vestiture highly caducous,
whence usually not present anymore; inferolateral flange
continued as a fine line a little beyond the locking groove.
No hind wings, not even stumps present.
Mesepimeral suture obsolete, not sulcate but
occasionally with a slight impression against elytra; mesoand
metasternal processes not meeting between coxae;
metasternum short, hind margin in front of coxae distinctly
concavely curved. Process of ventrite 1 broadly rounded;
suture 1 of abdomen laterally distinct; ventrite 5 in male
subtruncate, shallowly bisinuous, not rimmed at apex, in
female rounded. Tergite 1–6 totally depigmented; membrane
between tergites 7 and 8 lacking pouch in both sexes.
Fore coxae long, slender, slightly antemedian owing to
prothorax being ventrally rather long, a little less long in
front than behind coxae. Trochanters elongate, all on lower
edge longer than wide. Femora weakly swollen, hind ones
well short of reaching apex of elytra. Tibiae lacking mucro
in both sexes.Tarsi lineal, tarsite 2 weakly broadened apicad,
tarsite 3 with long, slender lobes; claw segment passing
tarsite 3 by half the length of this tarsite; claws divaricate,
slender, simple, without a tooth or lamina, Fig. 114.
Male. Tergite 8 as in Fig. 112–113, strongly rounded at
apex, a good deal visible ventrally beyond abdomen, lacking
carinae or flanges. Sternite 8 as in Fig. 115, with deep
emargination. Sternite 9 as in Fig. 115–116, with somewhat
symmetrical arms, these not or hardly shorter than apodeme,
with a heavily pigmented transverse sclerite articulating
with the tips of arms. Tegmen as in Fig. 117–118, as long
as aedeagus, distinctly articulated on sides, unusually robust
as a whole below articulation; the dorsal sector short,
strongly pigmented laterally and apically, entire at apex,
with a very short membrane at apex and a pair of short
setae, central area uniformly, weakly pigmented, bilobed
cephalad. Aedeagus (Fig. 119–120) very long, extending
deeply into the thoracic lumen; pedon parallel-sided, weakly
pigmented, ending in a long, subuliform apex; tectum and
tectal arms weakly pigmented; apodeme slightly longer
than main body, tightly articulating with pedon, internal
sac extending to a little beyond middle of apodemes, lacking
sclerites but with fine wall lining.
Female. Colleterial gland at base of common oviduct
absent. Bursa and spermatheca as in Fig. 121; one very
large egg present at any one time, a mature egg measuring
0.875 x 0.50 mm in a 1.4 mm long female, the egg extending
into the thoracic cavity.
Distribution. New Zealand, endemic.
Host plant. Unknown.
Remarks. One species, usually obtained from sifted bush
floor litter. In habitus not unlike the flightless Apotapion
Zimmerman (1943) of Fiji and Vanuatu and, apparently,
nearest to this genus in affinity for sharing similarly gibbous
prothorax and elytra, a rather long prosternum in
front of coxae, a subcompact antennal club, lack of an
apical constriction of prothorax, a concealed scutellum, no
humeral callus, no mucro on any tibia in both sexes, and
simple claws. Apotapion differs, however, considerably in
having a short antennal scape, broad tarsi, a shorter first
antennal club segment, an intersegmental sclerite near the
emargination of sternite 8, a distinct sclerite in the internal
sac, no bladal sclerite on sternite 9 of male, and normal
eyes without any glaze over ommatidia. One of the dissected
females had an egg (Fig. 157) that filled up virtually
the entire abdomen and good part of the mesothoracic lumen.
It is not uncommon that very small beetles have very
large eggs in relation to their size, for instance Ptiliidae
(Dybas 1966) and Limnichidae (Britton 1977).
Etymology. Zelápterus is derived from ‘zel’, short for the
Latin name of New Zealand (Nova Zelandia), and ápterus
for the lack of hind wings; gender masculine.
Zelapterus terricola (Broun) n. comb.
Fig. 10, 11, 110–121; Map 12
Broun, 1923: 702 (Apion)
Shiny black, antennae and legs reddish or dark brown.
Vestiture absent except for some hairs on legs and last
ventrite (Fig. 10). Other features are contained in the description
of the genus above. Because the original publication
shows accurate and detailed observations by Broun,
his description of Apion terricola is here reproduced in
full.
Original description. ‘Minute, elongate, very convex,
the elytra especially; glabrous, shining, nigrescent, rostrum,
antennae, and legs piceo-rufous, its punctiform sculpture
obsolete.’
‘Rostrum rather longer than thorax, arched, stout,
cylindrical, slightly narrower in front. Head of equal length
and breath, gradually narrowed to almost the same width