Two new species of the Hercostomus hamatus group (Diptera: Dolichopodidae) from China

2006·18 MB·

by  Liao, Y

BULLETINDEL'INSTITUTROYALDESSCIENCESNATURELLESDEBELGIQUE ENTOMOLOGIE.76:49-53.2006
BULLETINVANHETKONINKLIJKBELGISCHINSTITUUTVOORNATUURWETENSCHAPPEN ENTOMOLOGIE,76:49-53,2006
Two new species of the Hercostomus hamatus group
(Diptera: Dolichopodidae) from China
by Yinxia LIAO,ShanyiZHOU &Ding YANG
Abstract - Fore tarsomeres 3-4slightly flattened 9
7. Cercus with finger-like processes 8
TwonewspeciesoftheHercostomus hamatusgroupfromChina are - Cercus withoutfinger-like processes
described as new toscience. Akeytothe species ofthe group from
H. chiaiensisZhang etYang
Chinaispresented.
8. Lateral lobe on epandrium with long acute apex. .
Key words: Dolichopodidae,Hercoslomus, newspecies,China H. acutilobatus n. sp.
- Lateral lobeon epandrium uniformly thick
H. dissimilis Yang etSaigusa
Introduction 9. Aristadorsal to subapical 10
- Arista nearly apical
The Hercostomus hamatus-group is characterized by H. taitungensis Zhang etYang
the hind femur with a black tip, veins and M dis 10. First flagellomere obtuse apically
tinctly convergent apically, and cercus small triangular H. dissectus Yang etSaigusa
with several finger-like apical processesand longbristles - First flagellomere acute apically
(Wei, 1997; Zhang and Yang, 2003). It contains 31 H. curvispinus Yang etSaigusa
known species in China. In the present paper, 2 species 11. Aristadistinctly apical 12
are described as new to science. A key to the species of - Arista subapical to dorsal 15
the hamatus-gmup from China is given. The types are 12. Coxae wholly yellow
deposited in the Insect Collection of China Agricultural H. tianeensis Zhang etYang
University (CAU), Beijing. - Coxae not wholly yellow 13
13. Fore and hind coxae yellow, mid coxaslightly dark
14
Key to species (males) of the Hercostomus hamatus- - Fore coxa yellow,mid and hind coxae dark brown
groupfrom China H. hualienensis Zhang etYang
14. Lateral lobe on epandrium uniformly thick, strip
1. Subcosta swollen basically; fore tarsomere 5 with a like H.furcutusV^El
dorsal process 2 - Lateral lobe on epandrium narrowing apically . . .
- Subcosta not swollen; fore tarsomere 5 without dor H. apicilaris Yang et Grootaert
sal process 4 15. Thorax mostly yellow or partly yellow 16
2. Fore tarsomere 5 with very small dorsal process . - Thorax metallic green 19
H. prolixusWei 16. Lateral lobe on epandrium indistinct
Fore tarsomere 5 with large and wide dorsal proc H. longyuwanensisZhang et Yang
ess 3 Lateral lobe on epandrium distinctly projected. 17
3. Fore tarsomere 5 with dorsal process longer than 17. Lateral lobe on epandrium slightly curved, with 2
wide H. proctiis Wei apical bristles
Fore tarsomere 5 with dorsal process wider than H. xishuangbannensis Yang et Grootaert
long H.guizhouensis Wei - Lateral lobe on epandrium straight, finger-like, with
4. Fore tarsomeres 3-4 always flattened 5 1apical bristle 18
- Fore tarsus normal 11 18. Antenna dark brownish yellow except first flagel
5. PostocLilar bristles entirely black 6 lomere dark; scutellum with yellow margin
- Mid and lower postocularbristles yellow H. curvativus Yang etSaigusa
H. exacutusWei - Antennadark; scutellum metallic green
6. Fore tarsomeres 3-4 distinctly flattened 7 H. xanthodes Yang etGrootaert
Yinxia LIAO, Shanyi ZHOU & DingYANG
19. Scapeyellow 20 1.Hercostomusaciitilobatiis sp. nov.
- Scape dark brownorblack 26 (Figs. 1-6)
20. Hind coxayellow, sometimes basally brown . . 21
Hind coxa brown to darkbrown 23 Diagnosis: First flagellomere rather short, as long as
21. Cercus with 1-2long finger-like marginal processes wide; arista subapical. Fore tarsomeres 3-4 black and
22 distinctly flattened, tarsomere 5 brown. Left and right
- Cercus withoutfinger-like marginal process .... lateral lobes on epandrium asymmetric, acute apically.
H. erectusYang etGrootaert
22. Clypeus invisible lateral view; M slightly curved Description: Male. Body length 5.4- 5.7 mm, wing
forward after m-cu H. mustus Wei length 4.8-5.1 mm.
- Clypeus visible lateral view; M nearly straight .. Head metallic green with pale grey pollen. Face with
H.frondosus Wei palegrey pollen,face narrowingventrally,aswideasfirst
23. Lateral lobe on epandrium shorterthan epandrium flagellomere. Hairsandbristleson headblack.Postocular
H. solutiisWei bristles (including ventral hairs) entirely black. Antenna
- Lateral lobe on epandrium longer than epandrium (Fig. 1) black with wide ventral area of scape yellow;
24 first flagellomere nearly as long as wide, obtuseapically;
24. Lateral lobe on epandrium acute apically; cercus arista black, subapical, minutely pubescent, with basal
without distinctfinger-like process H.fistulas Wei segment 0.1 times as long as apical segment. Proboscis
Lateral lobe on epandrium thin and narrow api brownish yellow with black hairs; palpus brownish yel
cally; cercus with 2finger-like processes 25 low with black hairs and 1black apical bristle.
25. Aristawith basal segment0.3 times aslong asapical Thorax metallic green with pale grey pollen. Hairsand
segment;fore tibia yellow; lateral lobeonepandrium bristlesonthoraxblack. 6strongdc,7-8irregularlypaired
with long apical bristles acr short and hair-like. Scutellum with 2 pairs of bristles
H. acutatus Yang etYang (basal pair short and hair-like). Propleuron with several
- Arista with basal segment0.15 times as long as api yellow hairs and with 1 black bristle on lower portion.
cal segment; fore tibia brown apically; lateral lobe Legs yellow. Coxae yellow, mid coxa with one brownish
on epandrium with shortapical bristles yellow spot at middle. Fore and mid tarsi from tip of tar
H. hamatus Wei somere 1onward dark brown, tipofhind femur brownish,
26. Lateral lobe on epandrium very short, slightly pro hind tibia and tarsusfrom tipoftibia onward darkbrown.
jecting beyond tip of epandrium 27 Fore tarsomeres 3-4 black and distinctly flattened, tar
- Lateral lobe on epandrium distinctly projecting somere 5 brown (Fig. 3). Hairs and bristles on legs black.
beyond tip of epandrium 28 Mid and hind coxae each with 1 outer bristle, mid and
27. Lateral lobe on epandrium obtuse hind femur each with 1preapical bristle. Foretibia with 4
H. gansuensis Yang ad, apically with 2 bristles; mid tibia with 4 ad, 3 pd and
- Lateral lobe on epandrium somewhat acute 1av, apically with 4 bristles; hind tibia with 4 ad, 4 pd,
H.fastigiatus Wei lav, and one row short v, apically with 3 bristles. Hind
28.Lateral lobeonepandriumfinger-like, and with wide tarsomere 1with 2 shortv.Relative lengths of tibia and 5
base 29 tarsomeres: LI 2.50: 1.50 :1.65 :0.65 :0.30:0.25;LII3.2
Laterallobeonepandrium uniformly thick,apically :2.0 : 1.75: 1.25 :0.50 :0.30 ;LIII2.25 :0.63 : 1.25 :0.73
somewhatobtuse and curved apically 31 : 0.35 : 0.23. Wing (Fig. 2) tinged greyish; veins brown,
29. Cercus lobate with weak apical incision and 2 short and M slightly convergent apically; CuAx ratio 0.7.
marginal processes . H. concavus Yanget Saigusa Squamayellow with black hairs. Halteryellow.
Cercus with 2 long finger-like marginal processes Abdomen metallic green with pale grey pollen. Ster
30 num 4 with one V-shaped process. Hairs and bristles on
30. Firstflagellomere longerthan wide abdomen black. Male genitalia (Figs. 4-5): Epandrium
H. serriformis n. sp. distinctly longer than wide, nearly truncate apically;
- Firstflagellomere as long as wide left and right lateral lobes asymmetric, acute, each with
H. litargus Wei 1 long bristle on middle portion; cercus (Fig. 6) rather
31. Cercus with 2 long finger-like marginal processes small with 2 finger-like processes and long bristles.
32 Hypandrium irregularly furcated.
- Cercus with 4 longfinger-like marginal processes Female. Unknown.
H. wui Wei Holotype male, Guangxi: Dayaoshan National Nature
32. Hind tibia with 3pv H. histus Wei Reserve, 2005. VII. 24, Yajun Zhu. Paratype: 1 male,
- Hind tibia with 4 pv ... H. wudangshanus Yang same date as holotype.
Distribution: China (Guangxi).
Etymology: The specificnamerefers tothe acute lateral
lobe on the epandrium.
New species ofthe Hercostomus hamatus group
Figs. 1-6(cid:127) -Hercostomus aciitilobatus sp. nov. (male). 1.Antenna, lateral view; 2. wing; 3. fore tarsomeres 2-5, lateral view;
4. genitalia (excluding cercus), right lateral view;5.genitalia (excluding cercus), left lateral view;6. cercus, lateral
Remarks: The new species is somewhat similar to 2. Hercostomus serriformis sp. nov.
Hercostomus clissimilis Yang et Saigusa from Sichuan, (Figs. 7-11)
but maybeeasily separatedfrom the latter byhaving the
fore tarsomere 5 brown, CuAx ratio 0.7, left and right Diagnosis: Firstflagellomere 1.3timeslongerthanwide,
lateral lobes on the epandrium asymmetric, long and pointedapically;aristadorsal. Aedeaguswithmanyinner
large. In Hercostomus dissimilis, the fore tarsomere denticles.
5 is white, CuAx ratio is 0.5, and the lateral lobes on
s-:-
the epandrium are short and thick(Yang and Saigusa, Description: Male. Body length 5.4 mm, wing length
1999). 5.1 mm.
Yinxia LIAO, Shanyi ZHOU & DingYANG
New species of the Hercostomus hamatus group
Head metallic green with pale grey pollen. Face with Abdomenmetallicgreenwithpalegreypollen.Sternum
pale grey pollen, face narrowing ventrally, narrower 4 with a V-shaped ventral process. Hairs and bristles on
than first flagellomere. Hairs and bristles on head black. abdomen black. Male genitalia (Figs. 9-10): Epandrium
Postocularbristles(includingventralhairs)entirelyblack. distinctly longer than wide; lateral lobe on epandrium
Antenna (Fig. 7) blackish with ventral area of scape and large and curved, bearing 1 long and 2 short bristles
apical halfoffirst flagellomere yellow; first flagellomere apically; cercus (Fig. 11)rather small with 2 finger-like
1.3times longerthan wide, pointedapically; aristablack, processes and long bristles. Hypandrium irregularly fur
dorsal, with very short hairs, and with basal segment0.5 cated. Aedeagus long with many innerdenticles.
times as long as apical segment. Proboscis yellow with Female. Unknown.
black hairs; palpus yellow with black hairs and 1black Holotype male, Guangxi, Dayaoshan National Nature
apical bristle. Re.serve, 2005. VII. 26, YinxiaLiao.
Thorax metallic green with pale grey pollen, mesono-
tum and scutellum with grey brown pollen. Hairs and Distribution: China (Guangxi).
bristles on thorax black. 6 strong dc, 7 irregularly paired
acr short and hair-like. Scutellum with 2 pairs of bristles Etymology: The specific name refers to the serrate aea-
(basal pair short and hair-like), without marginal hairs. degus.
Propleuron with several yellow hairs and with 1 black
bristle on lower portion. Legs yellow. Fore and hind Remarks: The new species is somewhat similar to Her-
coxae yellow, mid coxa dark brown (except apex); fore co.stomus litargiL'iWei from Guizhou, but can be sepa
tarsus brown, tip of hind femur blackish, mid and hind rated from the latter by the first flagellomere 1.3 times
tarsi from tip oftarsomere 1onward dark brown. Hairs as longas wide and pointedapically, veins R^^, and M
and bristles on legs black. Mid and hind coxae each with weakly convergent apically, and aedeagus with many
1outerbristle, mid and hind femur each with 1preapical innerdenticles. In Herco.stomus litargus, the first flagel
bristle. Fore tibia with 3 ad, apically with 2 bristles; mid lomere isaslong aswide and obtuse apically, veins R_|^j
tibia with 3 ad and 2 pd, apically with 3 bristles; hind and M are distinctly convergent apically, and the aedea
tibia with 4 ad, 3 pd and 2 av, apically with 3 bristles. gus has no denticles (Wei, 1997).
Hind tarsomere 1with 1v.Relativelengthsoftibiaand5
tarsomeres: LI 2.2 : 1.2 :0.8 :0.5 :0.4 :0.3; LII 3.0 : 1.6
: 1.0 : 0.8 :0.4 :0.3 ; LIII 3.6 : 0.8 : 1.6 : ? : ? : ? [hind Acknowledgments
tarsomeres 3-5 missing]. Wing (Fig. 8) tinged greyish;
veins brown, and M slightly convergent apically; Weare verygratefultoMs.YajunZnu,Dr.Lili Zhangand Dr.Meng-
qing Wang (Beijing) for their help during the study. The research is
CuAx ratio 0.7. Squama yellow with black hairs. Halter
funded by the National Natural Science Foundation ofChina. (No.
yellow.
30225009).
References
Wei, L.,1997. Dolichopodidae (Diptera) from South western
China II. A study on the genus Hercostomus Loew, 1857.
Journal ofGuizhou Agricultural College 16(1): 29-41; 16(2):
36-50; 16(4): 32-43.
Yang, D. & Saigusa, T., 1999. New and little known Doli
chopodidae from China (VI): Diptera from Emei Mountain Yinxia Liao'^ Shanyi Zhou'& Ding Yang-*
(1). Bulletin de I'lnstitut Royal des Sciences Naturelles de 'College of Life Sciences,
Belgique, Entomoiogie69: 233-250. Guangxi Normal University, Guilin 541004, China;
Zhang,L.&Yang, D.,2003NotesonthegenusHercostomus -Department ofEntomology,
Loew,1857fromGuangxi,China(Diptera:Empidoidea:Doli ChinaAgricultural University, Beijing 100094, China
chopodidae).AnnalesZoologici53(4): 657-661. (*corresponding author)