Rhysacephala novacaledonica sp. nov. (Hymenoptera: Xiphydriidae), the first xiphydriid woodwasp from New Caledonia
Author
Jennings, John T.
Author
Austin, Andrew D.
Author
Schiff, And Nathan M.
text
Zootaxa
2007
1516
23
30
journal article
10.5281/zenodo.177308
77cf39fc-0c4a-45bb-918a-727a97d967c1
1175-5326
177308
Rhysacephala novacaledonica
Jennings & Austin
,
sp.nov.
(
Figs 1–7
)
Material Examined
Holotype
:
ɗ "
New Caledonia
22º14'Sx
166º50'E
Pic du Pin, site
2, 280m
26Nov2004
hand netting Burwell, Wright, rainforest". Deposited in the Muséum National d'Histoire Naturelle, Paris. Last 5 flagellomeres of left antenna and right hind tarsal segments 2–5 and claw missing.
FIGURE 1.
Distribution of
Xiphydriidae
in Australasia. A =
Austrocyrta australiensis
Riek
; C =
Cingalixiphia laeviceps
; M =
Moaxiphia
spp.; L =
Rhysacephala leai
; N =
R. novacaledonica
sp. nov.
; O =
R. obtusiventris
R =
R. rufipes
; T =
R. testacea
; and W =
R. wilsoni
.
Description
Male:
Length 7.0 mm (
Fig 2
). Head dark brown, thorax and abdomen black except for a broad yellow stripe on face along lower inner orbits of eyes, gena, malar space and lower hind orbits. Irregular yellow patch medially on lower frons and interantennal area, mandible yellow with brown margins, ventral surface of propleuron and thoracic sternites largely yellow, cenchri white, yellow dot medially on mesepisternum, antennae and legs light brown except variable amounts of yellow ventrally on coxae. Fore wing with a dark brown tint, hind wing lighter brown tint (
Fig. 3
).
FIGURE 2.
Lateral habitus of
R. novacaledonica
sp. nov.
Scale bar = 1.0 mm.
FIGURE 3.
Wings of
R. novacaledonica
sp. nov.
showing venation. Scale bar = 0.5 mm.
Head 1.24 x wider than long when viewed dorsally (
Fig. 4
). Face rugose (
Fig. 5
). Inner orbits of eyes more or less parallel (
Fig. 5
). Distance between antennal sockets
3 x
distance between an antennal socket and front of clypeus (
Fig. 5
). Vertex smooth except for a few scattered shallow punctures posteromedially, rugose near ocelli (
Fig. 4
). Gena smooth, carina present. Malar space 0.32 x height of eye, distinct antennal groove. Occipital carina broad (
Fig. 4
). Clypeus strigate. Mandible 4-dentate. Maxillary palp 7-segmented, labial palp 4-segmented. Antenna 19-segmented, scape 2.2 x length pedicel, first flagellomere equal to length of scape, 1.7 x as long as second flagellomere. Pedicel 2.3 x longer than wide.
FIGURES 4–9.
4.
Dorsal head of
R. novacaledonica
sp. nov.
;
5.
Frontal head of
R. novacaledonica
sp. nov.
;
6.
Dorsal thorax of
R. novacaledonica
sp. nov.
;
7.
Dorsal view of mesoscutum (M) and lateral corner of pronotum (P) of
R. novacaledonica
sp. nov.
;
8.
Dorsal scutellum, axillae and mesoscutellum of male of an undescribed
Austrocyrta
sp. from Mt Moffatt, Queensland, showing tubercule (arrowed) on scutellum;
9.
Dorsal view of pronotal collar (P) and mesoscutum (M) of
A. australiensis
, female. Scale bars 4-6, 8-9 = 0.2 mm; 7 = 0.15 mm.
Pronotal collar hidden on specimen, lateral corner carinate (
Fig. 7
). Mesoscutum strigate, with reticulate microsculpturing, medial patch on lateral mesoscutum reticulate (Figs 6,7). Mesoscutellum without dorsal area defined by a carina, without prominent tubercle near apex (
Fig. 6
). Axillae strigate. Metascutellum strigate with reticulate microsculpturing. Metapostnotum and mesepisternum rugose. Mesopleuron rugose anteriorly, imbricate posteriorly. Metapleuron rugose dorsally, rugulose ventrally. Mesepimeron broad, carinate.
Hind
femur 0.9 x length hind tibia. Tibiae with two apical spurs, although inner one very short on fore tibia.
Hind
basitarsus slightly longer than remaining segments combined, bilobed tarsal plantulae present distally on segments 1-4. Tarsal claws with small erect inner tooth. Fore wing vein 2A+3A complete, more or less even in colouration although apical part slightly paler, almost reaching wing margin (
Fig. 3
).
Hind
wing veins 3r-m and 2m-cu present (
Fig. 3
).
Hind
wing with 5 hamuli basally and 6 hamuli medially. Abdomen 2.4 x length thorax (
Fig. 2
), reticulate microsculpturing.
Female:
Unknown.
Remarks
This species lacks a prominent tubercle near the apex of the mesoscutellum (
Fig. 6
) placing it in the
Xiphydriinae
rather than the Derecyrtinae. It also has bilobed tarsal plantulae which are absent in most Derecyrtinae (
Benson 1954
;
Smith 1978
;
Schulmeister 2003
), although present in
A. australiensis
Riek
(Jennings unpublished). It exhibits the main characteristics for
Rhysacephala
as defined by
Maa (1949)
, and modified by
Benson (1954)
, including the inner orbits of the eyes being more or less parallel and having 7-segmented maxillary palps. The fore wing vein 2A+3A is more or less even in colour although apically a little paler, and almost reaches the wing margin (
Fig. 3
); in this respect it is not too dissimilar to the original diagnosis for the genus (
Maa 1949
;
Benson 1954
). Any differences are relatively minor and do not require the generic limits of
Rhysacephala
to be modified to accommodate this new species.
Although this species is similar in colour to the females of both
R. obtusiventris
and
R. rufipes
in which both the thorax and abdomen are black, it differs from the female of
R. wilsoni
which has a black thorax and a reddish brown abdomen,
Rhysacephala novacaledonica
can be distinguished from the male of
R. leai
in which both the thorax and abdomen are pale reddish brown. It can be distinguished from the male of
R. testacea
which also has the abdomen “infuscatus” (darkened), by
R. novacaledonica
having 19-segmented antennae compared with 13-segmented in
R. testacea
(
Mocsáry 1900
)
. It should be noted that a degree of caution must be exercised when comparing the colouration of different sexes as there is often a difference between the sexes.
The head of
R. novacaledonica
is similar to that of
R. leai
. Both have a broad yellow stripe on the face along the lower inner orbits of the eyes, gena, malar space and lower hind orbits, although the remainder of the head of
R. leai
is black whereas it is brown in
R. novacaledonica
(
Fig. 5
). It differs from
R. obtusiventris
,
R. rufipes
,
R. testacea
, and
R. wilsoni
which lack a stripe on the face and gena. It is interesting to note that
Cingalixiphia laeviceps
, which is distinguished from
Rhysacephala
by having a simple hind claw, also has a similar yellowish-white stripe (
Smith 1861
).
Rhysacephala novacaledonica
is known only from the
type
locality, Pic du Pin,
New Caledonia
(
Fig. 1
), and is named after this island. The name is to be treated as an adjective. Its biology is unknown. In
Brazil
, the xiphydriid woodwasp
Derecyrta araucariae
Mecke
is associated with
Araucaria angustifolia
(Bertol.) Kuntze (
Mecke
et al
. 2000
)
. Some 13 species of
Araucaria
and five species of
Agathis
(Araucariaceae)
are endemic to
New Caledonia
(
Lowry 1998
), and it seems reasonable to hypothesise that xiphydriid woodwasps may be associated with
Araucariaceae
in
New Caledonia
. Similarly,
D. beechei
Smith (Cupressaceae)
has been collected in
Chile
from
Fitzroya cupressoides
(Molina) Johnston
forest (
Smith 1995
), so other potential hosts in
New Caledonia
might also include
Cupressaceae
. Both
Callitris
spp. and
Neocallitropsis
spp. occur in
New Caledonia
(
Pye
et al.
2003
). Finally,
Basset (1991)
noted that
Rhysacephala
were found in the canopy of an
Argyrodendron actinophyllum
forest near Brisbane,
Australia
, although it is not clear whether it is its host.
Whilst
Argyrodendron
is an Australian genus, the genus
Acropogon
, with more than 20 species endemic to
New Caledonia
(
Morat & Chalopin 2005
), might be worth exploring as potential hosts.