334
Shamshev & Grootaert: A review of the genus Stilpon from the Oriental region
Female. Unknown.
Measurements. – Body length 1.5 mm, wing length 1.2 mm.
Etymology. – The name refers to the region where it was
first found.
Phylogenetic relationships. – The relationships of this species
are unresolved beyond inclusion within the S. divergens
group.
Distribution and seasonal occurrence. – Singapore. Found
in one locality only, in December during the rainy season in
Singapore.
Stilpon nhamdam, new species
(Figs. 60-63)
Material examined. – Holotype - male,
THAILAND: Loei
province, Na Haeo, river banks in gallery forest at Na Haeo FIRS,
sample n
°
20026, 27 May.2000, coll. P. Grootaert (SWU).
Paratypes – 1 female, same data as in holotype; 1 male, Na
Haeo, base waterfall at FIRS, sample n
°
21033, 6 May.2001,
coll. P. Grootaert; 1 male, 1 female, Na Haeo, in gallery forest
along stream at FIRS, sample n
°
21035, 6 May.2001, coll.
P. Grootaert; 7 males, 8 females, Dan Sai, along pond in
village (between school and market), sample n
°
21038, 8
May.2001, coll. P. Grootaert; 1 male, Na Haeo, gallery forest
along stream at FIRS, sample n
°
21044, 8 May.2001, coll.
P. Grootaert; 4 males, 7 females, Khring Nam Tok, river bed,
sample n
°
21046, 9 May.2001, coll. P. Grootaert; 2 males,
Khring Nam Tok, sample n
°
23041, 20 May.2003, coll. P.
Grootaert; 2 males, 2 females, Chang Nam Tok, river bed,
sample n
°
21047, 9 May.2001, coll. P. Grootaert). (in coll.
SWU, RBINS, ZRC).
Diagnosis. – Species with black thorax and mostly yellow
hind femur. Male: mid femur with basal swelling and long
black anteroventral spine.
Description. – Male. Head black in ground-colour, with
minute ocellars and long, cruciate inner verticals. Antenna
and palpus brownish yellow. Postpedicel nearly 2.0 times
longer than wide. Style about 5 times longer than postpedicel.
Thorax dark brown. Scutum entirely tomentose. Postpronotal
bristle long, inclinate. Dorsocentrals in multiple rows,
complete posteriorly. Acrostichals 2-serial, complete
posteriorly.
Legs with colour pattern: hind femur in apical 2/3, mid femur
in apical 1/3, fore tibia entirely (paler at base), fore tarsomere
1 (becoming paler toward apex), mid and hind tarsomere 5
brownish, fore tarsomere 5 contrast brown; tarsomeres 2-4
pale yellow; otherwise legs yellow. Mid coxa with 2 brown
bristles on outer side. Hind trochanter lacking spinules. Mid
femur (Fig. 60) with swelling in basal part, bearing long black
anteroventral spine near middle, 2 shorter brownish
Figs. 60-63. Stilpon nhamdam, new species, male. 60, mid leg, anterior view, 61, hypopygium, ventral view, 62, upper lobe of left surstylus,
dorsal view, 63, right surstylus, dorsal view. Scale bar: 0.1 mm.
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THE RAFFLES BULLETIN OF ZOOLOGY 2004
posteroventral spines and 1 long brownish yellow bristle in
extreme base. Hind femur (viewed laterally) evenly thickened
toward middle, with row of 7 anterodorsal subapical bristles
which scarcely longer than femur is deep and row of well
prominent dorsal bristles in basal half. Fore tibia lacking
prominent ventral bristles. Mid tibia shortened, with hardly
prominent ventral spinules in apical part and 1 longer spinule
at apex. Hind tibia unmodified.
Wing normally developed, covered with uniform microtrichia,
more or less uniformly infuscate. Vein R2+3 about 3.0 times
longer than Rs. Distance between apices of R2+3 and R4+5
subequal to distance between apices of R1 and R2+3. R4+5
and M strongly divergent in apical part. Halter with contrast
black elongate knob and pale stem.
Abdomen largely yellowish brown, bearing mostly scattered
dark setulae which are longer on pregenital segments, with
all tergites (except segment 8) of subequal in length, tergites
1-2 unmodified. Narrow gland-like structures present between
tergites 4-3 and 3-2.
Hypopygium (Fig. 61) brown. Hypandrium with 2 long
bristles in apical part. Epandrium completely divided. Left
epandrial lamella small, fused to hypandrium, with 2 long
bristles in apical part. Left surstylus with upper lobe (Fig.
62) undivided, with markedly developed surstylar comb.
Right surstylus (Fig. 63) moderately large, elongate, sublinear,
more or less rounded at apex, lacking spines. Left cercus
unbranched, digitiform, fairly long, lacking spines, with 1
strong ventral bristle and 2 thinner long marginal bristles
basally. Right cercus consisting of two lobes, lacking spines;
left lobe digitiform, fairly long, somewhat broadened in apical
part; right lobe short, broad, rounded at apex. Phallus long,
hair-like, curved.
Female. In most respects identical to male. Mid femur with
row of yellowish bristles. Abdomen paler. Terminalia
elongate. Segment 8 strongly sclerotized. Proximal margin
of sternite 8 without 2 anteriorly directed rods. Apex of
sternite 8 not partially separated from base. Sternite 10
uniformly sclerotized, not fused with ventroapical margin of
tergite 8. Cercus elongate oval, brownish yellow, clothed in
setulae of different length.
Measurements. – Body length 1.4-1.7 mm, wing length 0.9-
1.2 mm.
Etymology. – “Nham” (spine), “dam” (black)
refers to ventral
black spine on the mid femur.
Phylogenetic relationships. – The relationships of this species
are unresolved beyond inclusion within the S. divergens
group.
Distribution and seasonal occurrence. – Thailand. Only
know from Loei province in Northeast Thailand, but there
known from various sites. Quite common in May. Not found
in the Malaise trap, although it was common along the nearby
stream.
Stilpon trilobatus, new species
(Figs. 64-68)
Material examined. – Holotype - male,
THAILAND: Dan Sai,
along pond in village (between school and market), sample n
°
21038,
8 May.2000, coll. P. Grootaert (SWU).
Paratypes – 1 male, Krabi, Huai waterfall, river banks, sample
n
°
97113, 24.Oct.1997, coll. P. Grootaert; 1 male, Songkhla
province,
Ban Khlong Kua, in old rubber plantation, sample
n
°
97142, 29.Oct.1997, coll. P. Grootaert); 2 males, 5 females,
same data as in holotype; 1 female, Na Haeo, in gallery forest
along stream at FIRS, sample n
°
21035, 6 May.2001, coll.
P. Grootaert. (in coll. SWU, RBINS & ZRC).
Diagnosis. – Species with black thorax and almost wholly
brown hind femur. Male: mid femur slender, with a row of
almost equally long ventral bristles, 1 or 2 black spines in
apical third.
Description. – Male. Head black in ground-colour, with
minute anterior ocellars, somewhat longer posterior ocellars
and long inner verticals. Antenna and palpus light brown to
brownish yellow. Postpedicel nearly 2.0 times longer than
wide. Style about 5 times longer than postpedicel.
Thorax dark brown. Scutum entirely tomentose. Postpronotal
bristle long, inclinate. Dorsocentrals in multiple rows,
complete posteriorly. Acrostichals 2-serial, complete
posteriorly.
Legs with colour pattern: mid femur in apical 1/2, hind femur
(except extreme base) and tarsomere 5 of all legs brownish;
fore tibia, fore tarsomeres 1-4, hind coxa and hind tarsomere
1 brownish yellow; otherwise legs yellow. Mid coxa with 2
brown bristles on outer side. Hind trochanter lacking spinules.
Mid femur (Fig. 64) slender, with 2 anteroventral subapical
bristles, 1 long yellowish bristle in extreme base, row of 7-
8 yellowish to brownish yellow long spine-like bristles before
middle and 1 or 2 similar black spine-like bristles beyond
middle of femur. Hind femur (viewed laterally) evenly
thickened toward middle, with row of anterodorsal bristles
becoming longer toward apex (4-5 subapical bristles scarcely
longer than femur is deep) and row of prominent dorsal
bristles. Fore tibia lacking prominent ventral bristles. Mid
tibia with rows of ventral spinules and 1 longer subapical
spinule. Hind tibia unmodified.
Wing normally developed, covered with uniform
microtrichia; more or less uniformly and rather deep infuscate.
Costal vein with ordinary short setulae on anterior margin.
Vein R2+3 about 3.0 times longer than Rs. Distance between
apices of R2+3 and R4+5 1.2-1.3 times longer than distance
between apices of R1 and R2+3. R4+5 and M divergent and
evenly arcuate in apical part. Halter with elongate, contrast
knob and pale stem.
Abdomen largely yellowish brown, bearing mostly scattered
dark setulae which are longer on pregenital segments, tergites
1-2 unmodified, tergite 3 narrowed. Gland-like structures