New records of Black Fungus Gnats (Diptera: Sciaridae) from New Caledonia, with the description of two new Bradysia species and an updated checklist
Author
Köhler, Arne
Author
Menzel, Frank
text
Zootaxa
2013
3718
1
63
72
journal article
10.11646/zootaxa.3718.1.5
0878721a-e50b-46c5-81cb-ccfbb0134f80
1175-5326
285012
96892314-83B3-438D-A6A8-D7EA602EACAB
Bradysia irwini
sp. n.
(
Figs 2
,
8–12
)
Material examined.
Holotype
, male.
NEW CALEDONIA
: Province South, Mt. Koghis,
17 km
NNE of Noumeá,
550 m
a.s.l. Malaise trap,
13.XII.–20.XII.1998
, leg. N.J. Mary & M.E. Irwin (MNHN).
Description.
Male
.
Head.
Brown; eye bridge 3–4 facets wide. Antenna slightly paler, scape and pedicel yellowish; surface of flagellomeres rough, basal part of 4th flagellomere 2.3 times as long as wide, total length of flagellomere 4 (
Fig. 8
) 2.8 times as long as basal wide; setae on basal part of flagellomeres slightly shorter than width of flagellomeres with small sensilla among them. Maxillary palpus yellow; segment 1 as long as segment 2, with 2 bristles and a dorsal flat patch of sensilla; segment 2 with one long outer bristle; segment 3 is longest, 1.3 times as long as segment 1.
Thorax
(
Fig. 2
). Yellow-brown, posterior gradually darkened; thoracic bristles pale. Posterior pronotum bare. Anterior pronotum with 2 bristles. Episternum 1 with 6 bristles. Mesonotum with some stronger dorsocentrals (broken and missing on
holotype
) and with 4–5 longer and some weaker laterals. Scutellum with 2 strong and some shorter bristles. Katepisternum yellow coloured and as long as high.
Wing
(
Fig. 10
). Length =
1.6 mm
; width/length = 0.40. Wing membrane transparent, without macrotrichia; anal area well developed; all posterior veins without macrotrichia; veins distinct except slight m-stem; R, R1 and R5 only with dorsal macrotrichia; R1/R = 0.48; c/w = 0.62; r-m/bM = 0.77. Halteres brownish.
Legs
yellow; coxal bristles pale. Foretibia without small bristles among vestiture; tibial organ (
Fig. 9
) with a comb-like row of 9 bristles, more than half of tibial apex wide. Tibial spur slightly longer than width of tibial apex of foretibia, apically slightly bent towards tibia.
Hind
tibia with a posterodorsal row of dark bristles, extend 0.7 of tibial length. Claws with fine teeth.
Abdomen
(
Fig. 2
). Brown, with dark bristles.
Hypopygium
(
Fig. 12
). As brown as abdomen. Gonocoxites longer than wide, normal setosity; ventral, inner-side of gonocoxites v-shaped and without basal lobe of bristles. Gonostylus (
Fig. 11
) narrow, 2.75 times as long as wide and swollen at middle; apex of gonostylus rounded, slightly bent inwards and subapically with 2 equally long spines. Tegmen trapezoidal and membranous, with short and strongly sclerotized basal apodemes; area of teeth large, with strong, triangular teeth. Ejaculatory apodeme short and strong.
Body size
:
1.6 mm
.
Female
. Unknown.
Etymology.
We dedicate this new species to the collector Michael E. Irwin, Vail, Arizona [formerly of Urbana, Illinois] (
USA
), who sent us samples from different regions for our studies in the systematics of
Sciaridae
.
FIGURES 8–12.
Bradysia irwini
, holotype, male.
8.
4th flagellomere, lateral.
9.
Tibial organ on inner-side of foretibia.
10.
Wing.
11.
Gonostylus, ventral.
12.
Hypopygium, ventral. Scale bars: Figs 8, 9, 11, 12 = 0.1 mm; Fig. 10 = 0.5 mm.
Discussion.
Amongst the New Caledonian sciarids,
B
.
irwini
is similar to
B
.
gemellata
Vilkamaa, Hippa & Mohrig,
2012
in having two gonostylar spines (megasetae
sensu
Vilkamaa
et al.
2012c). This reduced number of gonostylar spines was construed as a unique feature of
B
.
gemellata
among the
New Caledonia
sciarids (Vilkamaa
et al.
2012c).
Bradysia irwini
may be distinguished from
B
.
gemellata
by the longer flagellomeres, the toothed claws, the inner-side of gonocoxites v-shaped and the slight subapical emargination of the gonostylus. Furthermore the c/w and r-m/bM ratios differ (c/w =
0.62 in
B
.
irwini
vs. c/w =
0.70–0.85 in
B
.
gemellata
; r-m/bM =
0.77 in
B
.
irwini
vs. both veins subequal in
B
.
gemellata
). In contrast to
B
.
gemellata
(belonging to
B
.
hilaris
group),
B
.
irwini
could be placed in the
B
.
fungicola
group
sensu
Menzel & Mohrig (2000). Characters like the long bristle on segment 2, claws with fine teeth and the v-shaped gonocoxal inner-side support this classification, although the absence of bristles in the vestiture of the foretibia and the trapezoidal tegmen are not typical characters of the
B
.
fungicola
group.