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THE RAFFLES BULLETIN OF ZOOLOGY 2004
10 plate-like or desclerotized medially, positioned below
proctiger. Cercus elongate-ovate or broad-ovate. Spermatheca
membranous, sac-like.
Key to Stilpon species from the Oriental region
1. Male ........................................................................................ 2
–
Female (unknown in S. crassinervis, S. khorngkeun, S.
malayensis,
S. monospinatus and
S. yai) ...................... 18
2. Thorax wholly black to brown .............................................. 3
–
Thorax at least with yellow pleurae .................................... 12
3. Hind femur constricted and bent near middle. Hind tibia (Fig.
71) with long spur-like posterior apical comb. Abdominal
tergite 1 (Fig. 84) produced laterally into small corner-like
projection bearing 3 black spine-like bristles. Cerci (Fig.
73) completely fused into one large elongate oval lobe
.......................................................................... S. paradoxus
–
Hind femur evenly thickened toward middle. Hind tibia with
ordinary posterior apical comb. Abdominal tergite 1
unmodified. Cerci more or less separated, except base .... 4
4. Distance between apices of veins R2+3 and R4+5 nearly 1.5
times shorter than distance between apices of veins R1 and
R2+3. R4+5 strongly curved at apex (Fig. 41). Hind
tarsomere 1 brown ...................................... S. khorngkeun
–
Distance between apices of veins R2+3 and R4+5 longer than
distance between apices of veins R1 and R2+3. R4+5 evenly
arcuate or straight. Hind tarsomere 1 yellow ................. 5
5. R4+5 and M parallel and straight in apical part. Mid femur (Fig.
76) with 3 black antero- and 2 longer posteroventral spines
in basal half ............................................................... S. yai
–
R4+5 and M more or less divergent and arcuate in apical part.
Mid femur with less numerous black spines .................. 6
6. Fore tibia with 1 erect ventral bristle in apical part. Wing brown
before and beyond vein M .............................................. 7
–
Fore tibia clothed in ordinary setulae. Wing lacking prominent
pattern, more or less infuscate, usually somewhat deeper
along veins ....................................................................... 8
7. Mid femur (Fig. 5) with 1 black short ventral spine just beyond
middle, 3 long yellowish bristles in basal part and row of
anteroventral brownish spinules before middle. Abdomen
with gland-like structures between tergites 3-2 and 2-1. Left
surstylus with markedly developed surstylar comb (Fig. 8).
Left cercus (Fig. 9) divided, with 3 apical spines
....................................................................... S. spinicercus
–
Mid femur (Fig. 1) lacking black spines, only with 3-4 yellow
long ventral bristles in basal part.
Abdomen without gland-
like structures. Left surstylus (Fig. 3) with hardly prominent
surstylar comb. Left cercus (Fig. 2) undivided, with 1 apical
spine ......................................................... S. monospinatus
8. Fore tibia brownish to brownish yellow. Mid femur brownish
at least in apical third ...................................................... 9
–
Fore tibia and mid femur yellow ......................................... 11
9. Mid femur (Fig. 60) with swelling in basal part, bearing 1 long
black anteroventral spine near middle. Hind femur brownish
in apical third ................................................ S. nhamdam
–
Mid femur slender, with different armature. Hind femur largely
brownish …….………….…………………………… 10
10. Mid femur (Fig. 64) bearing 2 black spines beyond middle. Hind
femur almost wholly brown, yellowish brown in extreme
base ................................................................ S. trilobatus
–
Mid femur with 3 posteroventral bristles in basal half. Hind
femur blackish in apical 3/4. Nepal .....
S. divergens Smith
11. Hind femur yellowish brown to brownish in apical 2/3. Halter
with contrastingly black knob and pale yellow stem.
Abdomen (Fig. 80) with gland-like structures between
tergites 4-3 and 3-2 .................................................. S. lek
–
Hind femur entirely yellow. Halter pale, knob with slight
brownish tinge. Abdomen (Fig. 81) with gland-like
structures between tergites 5-4, 4-3 and 3-2 ...... S. lekkwar
12. Scutum black, pleurae yellow. Mid femur (Fig. 54) with 2 short
dark posteroventral spines in basal 1/3 and 1 similar
anteroventral spine in apical 1/3. Abdomen (Fig. 83) with
gland-like structures between tergites 2-3 and 3-4. Upper
lobe of left surstylus (Fig. 57) with markedly developed
surstylar comb .............................................. S. malayensis
–
Scutum entirely yellow or with indistinct brownish spots near
postalar calli. Mid femur with pale basal bristles only.
Abdomen without gland-like structures. Upper lobe of left
surstylus lacking surstylar comb ................................... 13
13. Fore tibia and tarsomere 1 brown ........................................ 14
–
Fore tibia and tarsomere 1 yellow ....................................... 15
14. Postpronotal bristle long. Acrostichal and dorsocentral bristles
minute on prescutellar depression. Left cercus (Fig. 16) long,
right cercus undivided, short, broad, subrectangular
......................................................................... S. isaanensis
–
Postpronotal bristle hardly prominent. Acrostichal and
dorsocentral bristles quite long and distinct on prescutellar
depression. Left cercus (Fig. 22) very short, right cercus
consisting of two lobes ....................................... S. laawae
15. Vein R2+3 flattened at apex. Distance between apices of veins
R2+3 and R4+5 nearly 3.0 times longer than distance
between apices of veins R1 and R2+3 ...... S. crassinervis
–
Vein R2+3 ordinary. Distance between apices of veins R2+3
and R4+5 at most 2.0 times longer than distance between
apices of veins R1 and R2+3 ........................................ 16
16. Hind trochanter (Fig. 31) with 2 black ventral spines. Hind femur
with 3-4 fairly long anteroventral bristles in apical part.
Abdominal segment 8 with ordinary bristles. Left cercus
(Fig. 33) long, slender ...................................... S. seeluang
–
Hind trochanter lacking black spines. Hind femur with 5-6 fairly
long anteroventral bristles in apical part. Abdominal segment
8 with 2 very long bristles. Left cercus short .............. 17
17. Wing brownish before and beyond vein M. Left cercus (Figs.
26, 28) with 3 very long spines ................... S. nhamyaaw
–
Wing with indistinct pattern, more or less evenly infuscate. Left
cercus (Fig. 37) with ordinary bristles .................
S. taksin
18. Thorax black to brown ......................................................... 19
–
Thorax yellow ...................................................................... 24
19. Fore tibia brownish to brownish yellow ............................. 20
–
Fore tibia and mid femur yellow ......................................... 22
20. Hind femur brownish in apical 1/3 ........................
S. nhamdam
–
Hind femur largely brown to blackish ................................. 21
21. Hind femur blackish in apical 3/4 ............
S. divergens Smith
–
Hind femur almost wholly brown, yellowish brown in extreme
base .................................................................
S. trilobatus
22. Wing brown before and beyond vein M ............ S. spinicercus
–
Wing lacking prominent pattern, more or less infuscate ....... 23
23. Hind femur yellowish brown to brownish in apical 2/3
............................................................... S. lek / S. paradoxus
–
Hind femur entirely yellow ....................................... S. lekkwar
24. Postpronotal bristle long. Acrostichal and dorsocentral bristles
minute on prescutellar depression ................... S. isaanensis
-
Postpronotal bristle hardly prominent. Acrostichal and
dorsocentral bristles quite long
and distinct and reaching
base of scutellum ................................................ S. laawae
25. Hind femur with 3-4 fairly long anteroventral bristles in apical
part ...................................................................... S. seeluang
–
Hind femur with 5-6 fairly long anteroventral bristles in apical
part .................................................................................. 26
26. Wing brownish before and beyond vein M ........... S. nhamyaaw
–
Wing with indistinct pattern, more or less evenly infuscate
...................................................................................
S. taksin