BioOne sees sustainable scholarly publishing as an inherently collaborative enterprise connecting authors, nonprofitpublishers, academic institutions, research libraries, and research funders in the common goal of maximizing access tocritical research.

A new species of the genus Nearcticorpus Roháček andMarshall, 1982 from China (Diptera: Sphaeroceridae)Author(s): Lixin Su, Guangchun Liu, Jie Xu, and Jianfeng WangSource: Pan-Pacific Entomologist, 88(3):342-346. 2012.Published By: Pacific Coast Entomological SocietyDOI: http://dx.doi.org/10.3956/2012-31.1URL: http://www.bioone.org/doi/full/10.3956/2012-31.1

BioOne (www.bioone.org) is a nonprofit, online aggregation of core research in thebiological, ecological, and environmental sciences. BioOne provides a sustainable onlineplatform for over 170 journals and books published by nonprofit societies, associations,museums, institutions, and presses.

Your use of this PDF, the BioOne Web site, and all posted and associated contentindicates your acceptance of BioOne’s Terms of Use, available at www.bioone.org/page/terms_of_use.

Usage of BioOne content is strictly limited to personal, educational, and non-commercialuse. Commercial inquiries or rights and permissions requests should be directed to theindividual publisher as copyright holder.

A new species of the genus Nearcticorpus Rohacek and Marshall,1982 from China (Diptera: Sphaeroceridae)

LIXIN SU1, GUANGCHUN LIU

1, JIE XU2, & JIANFENG WANG

1

1Liaoning Key Laboratory of Urban Integrated Pest Management and Ecological

Security, Shenyang University, Shenyang 110044, China

Corresponding author: e-mail: Liugc@yahoo.cn2Shenyang Normal University, Shenyang 110034, China

Abstract. A first Palaearctic representative of the genus Nearcticorpus Rohacek and Marshall

1982 is described from China (Ningxia Hui Autonomous Region), viz. Nearcticorpus

palaearctictum sp. nov. (male only). Based on its description the diagnosis of the genus

Nearcticorpus is supplemented. The geographic distribution of the genus is updated and its

relations with Puncticorpus Duda, 1918 are discussed.

Key Words. Diptera, Sphaeroceridae, Nearcticorpus, China, new species.

INTRODUCTION

The genus Nearcticorpus was originally established by Rohacek and Marshall

(1982). Presently, the genus is known to include only two species worldwide (Rohacek

et al. 2001), both of which occur in the Nearctic Region. The purpose of this paper is to

describe a new species of the genus Nearcticorpus from China (representing the first

record of the genus from the Palaearctic Region) and provide new information on the

distribution and relationship between Nearcticorpus Rohacek & Marshall 1982 and

Puncticorpus Duda 1918. Some morphological characters of the new species

(posteriorly triangular prosternum, mid femur with a row of short posteroventral

short setae in proximal half) and the new distribution record of Nearcticorpus seem to

support the hypothesis of Marshall and Rohacek (1982) about the independent

Puncticorpus lineage but contradict the hypothesis about the historical biogeography of

the Nearcticorpus-Puncticorpus pair as formulated by Rohacek and Marshall (1982).

METHODS AND MATERIALS

The specimens were collected with sweep nets in forests of Liupan Mountains and

preserved in ethanol. They are deposited in Liaoning Key Laboratory of Urban

Integrated Pest Management and Ecological Security, Shenyang University,

Shenyang, Liaoning Province, China. The description and illustrations were

prepared from specimens or their dissected parts in ethanol or glycerine.

Morphological terminology mostly follows that of Rohacek (1998).

Nearcticorpus palaearcticum Su, sp. nov.

(Figs. 1–16)

Diagnosis. General color shiny black; legs shiny black except for trochanters,

apices of femora, bases of tibiae and tarsi, dark reddish brown; halter with stem pale

yellow and knob shiny black. Prosternum with triangularly widened posterior part.

Mid femur proximally with a row of short posteroventral setae. Sternite 4 with a

posteromedial process bearing 2 thick spines and numerous short setulae. Sternite 5

medially distinctly short, posterolaterally with medium long setae. Male genitalia

THE PAN-PACIFIC ENTOMOLOGIST88(3):342–346, (2012)

Figures 1–16. Nearcticorpus palaearcticum sp. nov. (- holotype). Figure 1. Mid tibia anteriorly.Figure 2. Mid tibia dorsally. Figure 3. Mid femur posterodorsally. Figure 4. Genitalia (aedeagalcomplex omitted) laterally. Figure 5. Genitalia posteriorly. Figure 6. Aedeagal complex laterally(postgonite omitted). Figure 7. Aedeagus laterally. Figure 8. Aedeagus ventrally. Figure 9. Rightpostgonite laterally. Figure 10. Left postgonite laterally. Figure 11. Prosternum ventrally. Figure 12.Tergite 5 dorsally. Figure 13. Sternites 1, 2 & 3 ventrally. Figure 14. Sternites 4 and 5 ventrally. Figure15. Synsternite 6 + 7 ventrally. Figure 16. Left wing. Scales. Figures 1–15 5 0.1 mm, Figure 16 5 0.5 mm.

2012 SU ET AL.: A NEW SPECIES OF NEARCTICORPUS FROM CHINA 343

(including the aedeagal complex) generally similar to those of N. canadense Rohacek

and Marshall 1982.

Description. Male. Body length ca. 2.0 mm, wing length ca. 1.3 mm. General color

shining black, including head, thorax and abdomen; legs shining black except for

trochanters, apices of femora, bases of tibiae and tarsi, dark reddish brown; halter

with stem pale yellow, knob shining black; whole abdomen heavily sclerotized and

distinctly granulose. Head: two orbital setae, anterior 0.6 times as long as posterior,

with additional setulae below and inside orbitals, 2–3 of the setulae stronger.

Postvertical setae small, slightly inclinate. Internal and external occipital setae long

(in contrast to Puncticorpus spp.), internal occipital seta longer than external.

Interfrontal setae in 3 pairs, 2 posterior pairs longer and subequal in length, anterior

short and thin. A minute pair of setulae below and outside interfrontals also present.

Eye height 3 times as long as genal height. Genal seta 1/3 as long as vibrissa. Aristal

hairs subequal in length to basal width of arista, but slightly elongate in its distal half.

Thorax. Prosternum triangular posteriorly. Thoracic chaetotaxy: 1 long humeral

seta; 2 dorsocentral setae, anterior very short and almost on the suture; acrostichal

setulae in 8 rows in front of suture. Katepisternum with 2 setae, posterior large seta-

like, anterior reduced to small setula. Laterobasal scutellar seta 0.43 times as long

as apical scutellar seta. Mid femur (Fig. 3) proximally with a row of short

posteroventral setae (4–5 thick and 2 thin), preapically with a short anterior seta.

Mid tibia (Figs. 1 and 2) proximally with a moderately long dorsal seta, distally with

a short anterodorsal and a longer dorsal and a short posterodorsal setae, ventrally

with several small setulae and a very small ventroapical seta. Wing (Fig. 16)

infuscated, veins brown. C hardly overpassing R4+5, first costal sector basally with

usual 2 pairs of setae. Second costal sector 0.88 times as long as the third, crossveins

r-m and dm-cu separated by twice the length of dm-cu. R2+3 distinctly sinuate,

apically slightly bent up to C. R4+5 slightly sinuate, apically slightly bent up to C.

Cell dm with appendages of M and CuA1. Anal vein straight but reduced. Alula

small and narrow, apically slightly acute.

Male abdomen. Syntergite 1 + 2 large, its length about 1.25 times as long as tergite

3 at middle, subequal in width to the latter. Tergite 4 slightly narrower than tergite 3

in width, its length 0.75 times as long as tergite 4. Tergite 5 (Fig. 12) shortened and

divided into 2 lateral sclerites. Sternite 1 (Fig. 13) extremely small, rectangular.

Sternites 2 and 3 very large and prolonged (Fig. 13) but less than those of N.

canadense, sternite 2 anteromedially concave. Sternite 4 very short, transversely

widened, with distinctive posteromedial lobe directed ventrally (Fig. 14), the latter

with 2 thick spines and numerous small setulae, posterolateral parts of sternite 4 with

a row of medium long setae. Sternite 5 (Fig. 14) medially short, laterally widened,

posterolaterally with medium long setae. Synsternite 6 + 7 (Fig. 15) posteromedial

membranous area with dense and small setae (the structure possibly belongs to

posteromedial part of sternite 5), below the area also with some indistinct structures.

Epandrium (Figs. 4 and 5) relatively shortly and uniformly setose. Cercus greatly

reduced, each cercus with 2 distinctly long and robust, closely arising setae (Fig. 5).

Subepandrial sclerite reduced, medially below anal fissure forming a slightly

asymmetrical ventral process. Hypandrium V-shaped. Surstylus highly characteristic

(Figs. 4 and 5), with large external lobe and slender, long, curved, internally directed

projection; external lobe armed by a short posterointernal process bearing a fine

seta, its posterior margin with 4 long and thick setae and its ventral margin with a

344 THE PAN-PACIFIC ENTOMOLOGIST Vol. 88(3)

group of 4 short setae. Basiphallus posterodoral margin with a small process in

lateral view (Fig. 7). Postgonites (Figs. 9 and 10) asymmetrical, robust; left

postgonite with robust external anteroproximal lobe; right postgonite with slender,

posteriorly bent apical part, and with slightly small external median lobe.

Distiphallus (Figs. 7 and 8) distinctly sclerotized, basal sclerite square in ventral

view, its ventroapical part with an apically bifurcate sclerite in ventral view and

dorsoapical part with 1 slender sclerite in lateral view, which formation is semi-

circular in ventral view, 2 apicolateral membranous parts spinulate. Ejacapodeme

invisible.

Female. Unknown.

Specimens Examined. Holotype -: China, Ningxia Hui Autonomous Region, Mt.

Liupan, Longtan, 2100–2150 m, 10.vii.2008, leg. Lixin Su. Paratype -: China,

Ningxia Hui Autonomous Region, Mt. Liupan, Longtan, 2100–2150 m, 10.vii.2008,

leg. Lixin Su; -: China, Shanxi, Qinshui, Zhongcun, Xiachuan, 1686m,19.vii.2012,

leg. Lixin Su.

Etymology. The specific epithet is derived from Palaearctic and refers to the first

palaearctic species of Nearcticorpus.

Remarks. The new species seems to be closely related to Nearcticorpus canadense

considering the distinctive similarities in the external characters and male abdomen

and genitalia. It can be easily distinguished from the latter by the shining black head,

basally triangular prosternum, extremely small sternite 1, the shape of tergite 5 and

sternites 4 and 5, and structures of male genitalia.

DISCUSSION

Some characters of the new species (particularly the posteriorly triangular

prosternum, a row of posteroventral bristles on proximal half of mid femur and

extremely small sternite 1) have not been known in the Nearcticorpus species but occur

in species of Puncticorpus. The triangular prosternum has even been considered an

apomorphic character of Puncticorpus (cf. Rohacek and Marshall 1982: fig. 77).

Although these characters seem to indicate an intermediate position of the new species

between both genera, the new species surely is derived from the Nearcticorpus clade

(demonstrated by presence of many apomorphies supporting this genus, cf. Rohacek

and Marshall 1982: fig. 77) and both above characters have thus evolved as

homoplasies in the Chinese species. It should be stressed that neither triangular

prosternum nor (more so) ventrally setose mid femur are unique characters of

Puncticorpus. On the contrary, both are known to evolve independently many times in

various genera of Limosininae (the triangular prosternum more often in terricolor and

flightless species). Consequently, the presence of these features in the new species only

demonstrates that the genera Nearcticorpus and Puncticorpus are closely related, as has

already been assumed. However, considering the above facts, the diagnosis of the

genus Nearcticorpus has to be supplemented as follows: male mid femur ventrally with

row of posteroventral setae or finely haired; prosternum posteriorly linear to

triangular; postvertical setae distinct to reduced but always present; preabdomen with

tergites minutely to distinctly granulate; sternite 1 entirely disappering to distinctly

present; male sternite 4 without articulate appendage but prolonged posteromedially

or projecting into a process; male sternite 5 shortened medially and laterally with

distinctly haired or setose; distiphallus of medium to small size.

2012 SU ET AL.: A NEW SPECIES OF NEARCTICORPUS FROM CHINA 345

Rohacek and Marshall (1982) proposed that the European Puncticorpus spp. are

possibly derived from the North American Nearcticorpus spp. However, the newspecies has the characters of both genera, and its discovery and expansion of the

known distribution of Nearcticorpus into Asia suggest that the European

Puncticorpus spp. are derived from the Asian Nearcticorpus rather than reaching

Europe via a trans-Atlantic land bridge as suggested by Rohacek and Marshall

(1982).

ACKNOWLEDGMENT

The authors are sincerely grateful to Mr. Yifan Liu, University of Illinois atUrbana-Champaign, U.S.A., for providing valuable references. This research is

supported by the National Science Foundation of China (No. 30770252,

No. 31071965) and Project for the Insect Resources Investigation of Liupan

Mountain (LIR0810).

LITERATURE CITED

Marshall, S. A. & J. Rohacek. 1982. Two new species and a new Nearctic record in generaApteromyia and Nearcticorpus (Diptera: Sphaeroceridae). Annals of the EntomologicalSociety of America 75:642–648.

Rohacek, J. 1998. Chapter 3.43. Family Sphaeroceridae, pp. 463–496. In: Papp, L. & Darvas, B.(Eds.). Contributions to a Manual of Palaearctic Diptera. Volume 3, Higher Brachycera.Science Herald, Budapest, 880 pp.

Rohacek, J. & S. A. Marshall. 1982. A monograph of the genera Puncticorpus Duda, 1918 andNearcticorpus gen. n. (Diptera, Sphaeroceridae) Zoologische Jahrbucher, Abteilung furSystematik, Okologie und Geographie der Tiere 109:357–398.

Rohacek, J., S. A. Marshall, A. L. Norrbom, M. Buck, D. I. Quiros & I. Smith. 2001. WorldCatalog of Sphaeroceridae (Diptera). Slezske Zemske Muzeum, Opava, 414 pp.

Received 12 Apr 2012; Accepted 10 Aug 2012 by M. Hauser; Publication date 19 Nov2012.

346 THE PAN-PACIFIC ENTOMOLOGIST Vol. 88(3)