N sp. (Guangdong). Both species are described and illustrated

---

        Genus                               Vol. 16(2): 299-305                          Wroc³aw, 30 VI 2005

Two new species of the genus Stilpon L

OEW

 from China

(Diptera: Hybotidae)

I

GOR

 S

HAMSHEV

1

, P

ATRICK

 G

ROOTAERT

2

 and D

ING

 Y

ANG

3

1

Permanent address: All-Russian Institute of Plant Protection, shosse Podbel’skogo 3, 188620,

St.Petersburg – Pushkin, Russia (e-mail: [e-mail]); temporary at Royal Belgian

Institute of Natural Sciences, Brussels

2

Department of Entomology, Royal Belgian Institute of Natural Sciences, Rue Vautier 29,

B-1000, Brussels, Belgium (e-mail: [e-mail])

3

Department of Entomology, China Agricultural University, Beijing 100094, China

([e-mail])

A

BSTRACT

. The genus Stilpon L

OEW

 (Diptera: Hybotidae) is recorded for the first

time from China with two species new to science: S. freidbergi n. sp. (Taiwan) and

S. nanlingensis n. sp. (Guangdong). Both species are described and illustrated.

Key words: entomology, taxonomy, Diptera, Empidoidea, Hybotidae, Stilpon, new

species, Palaearctic, China.

INTRODUCTION

This paper presents the first record of the Tachydromiinae fly of the genus

Stilpon L

OEW

 from China. Two species new to science have been discovered, one

from Taiwan and a second one from the southern Chinese province Guangdong.

The record of this group of empidoids from China is not a surprise because Stilpon

species are common and very diverse in the Oriental realm (S

HAMSHEV

 & G

ROOTAERT

2004a). Additionally, the genus has been recently found to occur in Middle Asia

and the Russian Far East (S

HAMSHEV

 & G

ROOTAERT

 2004b). Phylogenetically, the

two species described below are more closely related to some Oriental species

rather than to those discovered from the Nearctic (C

UMMING

 & C

OOPER

 1992) or

Palaearctic. Taking into account the great natural diversity of the Chinese terri-

---

300

IGOR SHAMSHEV, PATRICK GROOTAERT, DING YANG

tory it is evident that in the future undescribed species may yet be found from that

area, especially from the southern provinces.

The study is based on Diptera material deposited in the Entomological Mu-

seum of China Agricultural University (CAU, Beijing) and in Tel Aviv University

(Israel). For details of the methods, including morphological terms and descrip-

tive format, we refer to the paper published recently by the authors (S

HAMSHEV

 &

G

ROOTAERT

 2004a). In the descriptions, right and left sides of the male terminalia

are based on the unrotated position viewed posteriorly, such that in the illustra-

tions the right surstylus appears on the readers left side and vise versa. The male

terminalia are figured in their unrotated position.

SYSTEMATIC ACCOUNT

Stilpon freidbergi n. sp.

T

YPE

 

MATERIAL

Holotype: Male, Taiwan center, Mushe (Jenai), 1000 m, Taichung 45 Km E.,

Rt. 14, 5X93, (F. K

APLAN

 and A. F

REIDBERG

). Deposited in Tel Aviv University,

Israel.

D

IAGNOSIS

Species with wholly black thorax; legs almost wholly yellow, only tarsomere

5 of all legs black; mid femur with 1 row of 5 ventral spine-like bristles in basal

part; hind femur constricted and bent near middle; abdominal gland-like struc-

tures not prominent; male terminalia lacking spines, surstylar comb present,

small.

D

ESCRIPTION

Male: Body length 1.5 mm, wing length 1.4 mm. Head black in ground-

colour. Occiput subshining, finely greyish pollinose. Two moderately long, black,

vertical bristles present. Frons linear with sides nearly parallel, rather broad,

nearly 4 times as broad as anterior ocellus, entirely tomentose. Clypeus silvery

white tomentose. Antenna with scape and pedicel reddish yellow, postpedicel and

style brown. Palpus pale yellow, with rather short, black, subapical bristle.

Thorax black in ground-colour. Scutum entirely tomentose. Postpronotal

bristle long, inclinate. Dorsocentral bristles in multiple rows, complete posteriorly.

Acrostichal bristles 2-serial, complete posteriorly.

Legs almost wholly yellow, tarsomere 5 of all legs black. Mid coxa with 2

yellow bristles on outer side. Hind trochanter lacking spinules. Fore femur mark-

edly thickened, with rows of moderately long antero- and posteroventral bristles.

Mid femur (Fig. 1) slender, with 1 row of 5 ventral, brownish, spine-like bristles

in basal part and 1 longer, yellow bristle near base.

Hind femur (viewed laterally) constricted and bent near middle, with several

dorsal, erected, black bristles beyond constricted part of femur, bearing some

---

301

TWO NEW SPECIES OF THE GENUS STILPON

prominent dorsal, yellow bristles near base and 1 row of black, anteroventral

bristles in apical half (3 bristles longer).

Fore tibia spindle-like, with ordinary setation. Mid tibia with row of black,

ventral spinules and 1 longer subapical spinule. Hind tibia with unmodified

1-6.  Stilpon freidbergi n. sp., male: 1 - mid leg, anterior view, 2 - hypopygium ventral view, 3 -

subapical bristles on hypandrium, dorsal view, 4 - left surstylus and left cercus, right lateral view, 5

- right surstylus, dorsal view, 6 - apical part of right surstylus, dorsal view. Scale 0.1 mm

---

302

IGOR SHAMSHEV, PATRICK GROOTAERT, DING YANG

posterior apical comb, clothed in moderately long, erect bristles. Tarsomeres of

all legs unmodified.

Wing normally developed, covered with uniform microtrichia; more or less

uniformly, finely infuscate. Costal vein with moderately long setulae along ante-

rior margin. Vein R2+3 about 3 times longer than Rs. Distance between apices of

veins R2+3 and R4+5 subequal to distance between apices of veins R1 and R2+3.

Veins R4+5 and M1+2 slightly divergent and arcuate in apical part. Halter yellow.

Abdomen largely brownish yellow, pregenital segments darker. Intersegmen-

tal gland-like structures not prominent.

Hypopygium (Fig. 2) brown, rather small. Hypandrium with 2 long, spine-like

bristles sitting on elongate tubercle (Fig. 3). Epandrium completely divided. Left

epandrial lamella small, fused to hypandrium, with 2 long bristles in apical part. Left

surstylus (Fig. 4) with upper lobe undivided, with small surstylar comb. Right

surstylus (Figs 5, 6) moderately large, subtriangular, elongate, lacking spines. Cerci

unbranched, subequal in size and similar in shape, rather subtriangular, lacking

spines, ventral bristle and left marginal bristles in basal part. Phallus short.

Female: unknown.

E

TYMOLOGY

The new species is dedicated to Dr. A

MNON

 F

REIDBERG

 of Tel Aviv University

(Israel) who collected it and many other interesting empidoids.

D

ISTRIBUTION

China: Taiwan.

R

EMARKS

The new species can be readily distinguished from all known Palaearctic

species of Stilpon by the hind femur constricted and bent near middle. Within the

key to the species from the Oriental realm (S

HAMSHEV

 & G

ROOTAERT

 2004a)

S. freidbergi would run to S. paradoxus  S

HAMSHEV

 & G

ROOTAERT

 known from

Thailand only. However, this species has the hind tibia with long, spur-like

posterior apical comb and abdominal tergite 1 produced laterally into a small

corner-like projection bearing 3 black, spine-like bristles. Some Nearctic species

possessing the hind femur constricted and bent near middle differ primarily from

S. freidbergi in incompletely tomentose scutum (C

UMMING

 & C

OOPER

 1992). The

relationships of the new species are not quite clear but it appears to show some

affinities to the Oriental S. paradoxus and S. yai S

HAMSHEV

 & G

ROOTAERT

.

Stilpon nanlingensis n. sp.

T

YPE

 

MATERIAL

Holotype: Male, China: Guangdong province, Ruyuan Nanling, 7 May 2004

(National Nature Reserve, near headquarters; alt. 1000 m; sample n° 24010, coll.

P. G

ROOTAERT

). Deposited in CAU.

---

303

TWO NEW SPECIES OF THE GENUS STILPON

D

IAGNOSIS

Species with wholly black thorax; legs with tibiae and tarsi entirely brown;

mid femur with 3 posteroventral spine-like bristles in basal 1/3 and 1 row of 8

anteroventral shorter bristles; wings deeply infuscate, with veins R4+5 and M1+2

straight, subparallel in apical part; abdominal gland-like structures not prominent;

male terminalia lacking spines, with markedly developed surstylar comb.

7-11. Stilpon nanlingensis n. sp., male: 7 - mid leg, anterior view, 8 - hypopygium ventral view, 9

- left surstylus, ventro-lateral view, 10 - same, dorsal view, 11 - right surstylus, dorsal view. Scale

0.1 mm

---

304

IGOR SHAMSHEV, PATRICK GROOTAERT, DING YANG

D

ESCRIPTION

Male: Body length 2.4 mm, wing length 1.9 mm. Head black in ground-

colour. Occiput subshining, finely greyish pollinose. Two long, black, vertical

bristles present. Frons linear with sides nearly parallel, rather broad, nearly 3

times as broad as anterior ocellus, entirely tomentose, subshining. Antenna with

scape and pedicel yellow, postpedicel and style yellowish brown. Ocellar tubercle

with minute setulae. Palpus pale, with moderately long, black, subapical bristle.

Thorax black in ground-colour. Scutum entirely tomentose. Postpronotal

bristle long, inclinate. Dorsocentral bristles in multiple rows, complete posteriorly.

Acrostichal bristles 2-serial, complete posteriorly.

Legs with fore coxae and trochanters yellow, mid and hind coxae and

trochanters yellowish brown; fore femur largely brownish yellow, darker dorsally,

mid and hind femora yellow in basal half and brownish in apical half; tibiae and

tarsi entirely brown. Hind trochanter lacking spinules. Fore femur markedly

thickened, with rows of moderately long antero- and posteroventral bristles. Mid

femur (Fig 7) slender, with 3 posteroventral, moderately long, black, spine-like

bristles in basal 1/3, 1 row of 8 anteroventral, shorter, spine-like bristles and 1

long, subapical bristle anteriorly. Hind femur (viewed laterally) evenly thickened

toward middle, with 1 row of anteroventral bristles (about 4 subapical ones

longer), bearing some dorsal erect bristles near base. Fore tibia spindle-like, with

ordinary setation. Mid tibia with 1 row of black ventral spinules. Hind tibia with

unmodified posterior apical comb, clothed in moderately long, erect bristles. Fore

and mid tarsomeres slender, hind tarsomere 1 thickened.

Wing normally developed, covered with uniform microtrichia, uniformly,

rather deeply infuscate. Costal vein with long setulae along anterior margin. Vein

R2+3 about 2.5 times longer than Rs. Distance between apices of veins R2+3 and

R4+5 somewhat (1.2 times) longer than distance between apices of veins R1 and

R2+3. Veins R4+5 and M1+2 straight, subparallel in apical part. Halter with

yellow stem and black knob.

Abdomen mostly with light brown tergites and sternites, bearing hardly

prominent bristles; segment 8 dark brown, with several moderately long bristly

hairs. Most of sternites (except for sternites 7 and 8) divided by narrow, yellow,

median area into two parts. Intersegmental gland-like structures not prominent.

Hypopygium (Fig. 8) dark brown, rather large. Hypandrium lacking bristles in

apical part. Epandrium completely divided. Left epandrial lamella rather small,

fused to hypandrium, with 4 long bristles in apical part. Left surstylus (Figs 9, 10)

largely divided; lower part with greatly developed surstylar comb, upper part

digitiform, fused with lower part basally. Right surstylus (Fig 11) moderately

large, bilobed, lacking spines. Left cercus consisting of two lobes, lacking spines,

ventral bristle and left marginal bristles in basal part. Right cercus unbranched,

small, lacking spines. Phallus short.

Female: unknown.

---

305

TWO NEW SPECIES OF THE GENUS STILPON

E

TYMOLOGY

The new species is named after the type locality.

D

ISTRIBUTION

China: Guangdong.

R

EMARKS

S. nanlingensis is most closely related to S. yai known from Thailand only

(S

HAMSHEV

 & G

ROOTAERT

 2004a). It can be readily distinguished from the latter by

the armature of the male mid femur and by darker legs.

A

CKNOWLEDGEMENTS

This study was supported by a grant of the Belgian Federal Office for

Scientific Policy and   the National Natural Science Foundation of China

(No.30070100, No.30225009). We are thankful to Dr. Amnon F

REIDBERG

 (Tel

Aviv University, Israel) for providing material used in this paper.

REFERENCES

C

UMMING

, J. M., C

OOPER

, B. E., 1992. A revision of the Nearctic species of the Tachydromiinae fly

genus Stilpon L

OEW

 (Diptera: Empidoidea). Can. Ent., 124: 951-998.

S

HAMSHEV

, I. V., G

ROOTAERT

 P., 2004a. A review of the genus Stilpon  L

OEW

, 1859 (Empidoidea:

Hybotidae) from the Oriental Region. Raffles B. Zool., 52: 169-200.

—, in press. New data on the genus Stilpon L

OEW

 (Diptera: Hybotidae) from the Palaearctic region,

with description of a new species from Tajikistan. Belgian J. Ent.