Planaeschna robusta, Zhang, Hao-Miao & Cai, Qing-Hua, 2013

Zhang, Hao-Miao & Cai, Qing-Hua, 2013, Discovery of four new species of the genus Planaeschna from Southwestern China (Odonata: Anisoptera: Aeshnidae), Zootaxa 3741 (2), pp. 254-264 : 254-257

Planaeschna robusta sp. nov.

Figs. 1–9

Material examined. Holotype male, Mt. Emeishan, Wannian Temple (29°35'N, 103°23'E), altitude 880 m, Emeishan City, Sichuan Province, China, Haomiao Zhang leg., 16. VIII. 2007; paratypes: 2 ♂, same data; 5 ♂ 2 ♀, same locality and collector, 20. VIII. 2007; 1 ♂ 1 ♀, same locality and collector, 23. VIII. 2007; 3 ♂, Mt. Qingchenshan, Sichuan Province, Dujiangyan City, China, Haomiao Zhang leg., 31. VIII. 2007.

Species Localities and sources

Planaeschna taiwana Asahina, 1951 Taiwan (Asahina, 1951)

Planaeschna risi risi Asahina, 1964 Taiwan (Asahina, 1964) and Fujian (Lieftinck et al., 1984) Planaeschna suichangensis Zhou & Wei, 1980 Fujian (Karube, 2002), Zhejiang (Zhou & Wei, 1980),Guangdong

(Wilson & Xu, 2008), and Guangxi (Wilson, 2005) Planaeschna ishigakiana flavostria Yeh, 1996 Taiwan (Yeh, 1996)

Planaeschna celia Wilson & Reels, 2001 Hainan (Wilson & Reels, 2001)

Planaeschna shanxiensis Zhu & Zhang, 2001 Shanxi (Zhu & Zhang, 2001)

Planaeschna gressitti Karube, 2002 Guangdong (Karube, 2002)

Planaeschna maolanensis Zhao & Bao, 2002 Guizhou (Zhao & Bao, 2002)

Planaeschna haui Wilson & Xu, 2008 Guangdong and Guangxi (Wilson & Xu, 2008) Planaeschna nanlingensis Wilson & Xu, 2008 Guangdong (Wilson & Xu, 2008)

Planaeschna skiaperipola Wilson & Xu, 2008 Guangdong and Hong Kong (Wilson & Xu, 2008) Planaeschna liui Xu, Chen & Qui, 2009 Fujian (Xu et al, 2009)

Planaeschna laoshansensis Zhang, Yeh & Tong, 2010 Shandong (Zhang et al., 2010)

Planaeschna nankunshanensis Zhang, Yeh & Tong, 2010 Guangdong (Zhang et al., 2010)

Etymology. The name robusta means ‘strong and large’; the new species is rather large in the genus, especially the female, and both sexes are rather robust.

Diagnosis. Large sized for the genus, body mainly black with green maculations; separated from its closest congeners by details of body marking and structure of male appendages.

Holotype Male: Head fundamentally yellowish greeen with black markings, eyes bluish green in living specimen ( Figs. 1–2 ). Mid lobe of labium brownish yellow, lateral lobes blackish brown, labrum black with a large central yellow spot. Anteclypeus entirely dark brown, postclypeus yellow. Frons yellowish green frontally, with a large black spot, and dark brown dorsally without “T” mark.

Prothorax black. Synthorax black with greenish yellow markings as follows ( Fig. 1 ): mesepisternum with antehumeral stripe slightly bent and tapering ventrad, and a small rounded spot in the posterior lower corner; carina with a brown stripe; mesepimeron with a broad stripe; metepisternum with a triangular spot near the upper margin, an olive-shaped spot in middle, and a very small spot under the metastigma; metepimeron with a broad stripe; mesokatepisternum and metakatepisternum each with a yellow spot. Legs mainly black, coxae yellow posteriorly, inner margin of femur in fore and mid legs with yellow stripes ( Fig. 1 ).

Wings hyaline. Triangle 5-celled in fore wings and 4-celled in hind wings, anal loop 6- or 7-celled, anal triangle 3-celled. Pterostigma blackish brown, 2.5 mm in length. Nodal index: 17: 22: 24: 16 / 17: 16: 16: 17.

Abdomen black with greenish yellow markings as follows ( Fig. 1 ): S1 with very fine dorsal stripe and large spot laterally; S2 with triangular AD spot, pair of triangular MD spots, linear PD spot and very fine longitudinal line posteriorly, side of S2 with large AL spot covering auricle and two separated PL spots; S3 with triangular AD spot, paired triangular MD spots, paired semicircular PD spots and large AL spots, the PL spots reduced; S4–8 with paired triangular MD spots and AL spots, the MD spots and AL spots connected on S4–5; S4–S5 with paired oliveshaped PD spots. S9–10 black, S10 with a very short pyramidal process dorsally.

Anal appendages black. Superior appendages in lateral view suddenly expanded and broadest at basal 1/4, tapering slightly toward apex ( Fig. 6 ); in dorsal view, expanded at apical 3/5, with small apical spine ( Fig. 5 ). Inferior appendage slightly longer than half length of superior appendages, slightly bent with apical small tuberculate process in lateral view ( Fig. 6 ).

Vesica spermalis brown and black ( Figs. 7–8 ): Vesicle hollow anteriorly; 2nd segment strongly bending with stout projection dorsally; 3rd segment almost straight, slightly tapered distally; 4th segment with two lobes, each with protruding ear-shaped lobe and tapered apex in ventral view; in lateral view median bulge with two obvious “camel humps.”

Paratype female: Head color pattern similar to that of male, eyes green in living specimen ( Figs. 3–4 ).

Thoracic maculation similar to male, with more developed stripes on metepisternum ( Fig. 3 ).

Wing base tinted with amber. Triangle 5- or 6-celled in fore wings and 4-celled in hind wings, anal loop 12- celled. Pterostigma blackish brown, 2.5 mm in length. Nodal index: 22: 27: 25: 22 / 23: 20: 19: 22.

Abdomen black with yellow stripes ( Fig. 3 ): S1 with large spot dorsally and rectangular spots laterally; S2 with large AD spot, paired MD spots and trapezoidal PD spot, side of S2 with very broad band; S3–4 with AD spot, reduced on S4; S3–7 with paired triangular MD spots; S3–6 with PD spots; S3–8 with AL spots, S3–6 with PL spots; tergite of S10 ventrolaterally produced. Ovipositor pale brown, reaching end of S10. Superior appendages 2.5 times the length of S10 ( Fig. 9 ).

Measurements (mm). Holotype: total length 69.0, abdomen (including anal appendages) 54.0, hind wing 46.0. Paratype female: total length 74.5; abdomen (including anal appendages) 58.0, hind wing 51.0.

Distribution. China (Sichuan).

Notes on biology. The new species was locally common at the type locality Emeishan Mountain in August. All the materials collected were in the prime of life. During the long survey period in Emeishan (about two weeks), there were no sunny days and it rained quite often. It seems the species prefers the gloomy weather, and they even fly in the rain. Most individuals were collected from 14:00h to 19:00h, although some females could be seen in the morning. In a valley about 1300 m high, with no stream but a very open grassland, they foraged about 2 m above ground and at a low speed. Some other strong flyers, including Aeshna petalura Martin, 1909 , Polycanthagyna erythromela s (McLachlan, 1896), Polycanthagyna melanictera (Selys, 1883) and Macromia moorei moore i Selys, 1874, also wandered there but flew much higher. The new species was also found in many very shady and narrow streams in Emeishan; all the individuals were observed only foraging. In Qingchengshan Mountain, the new species was found in a semi-shady stream over 5 m wide. Males appeared after 16:00h and flew rather fast along the stream; sometimes one male would stop in the stream margin and fly back and forth. Mating and oviposition were not observed.

Discussion. The new species is outstanding by its large body size and bright green markings. It is very similar to P. suichangensis by the bent superior appendages which are broadest at basal 1/4 and tapering to the apex. It is very easy to separate P. robusta from P. suichangensis by the much more developed thoracic stripes and abdominal markings. From the structure of the vesica spermalis and appendages in dorsal view, the new species is similar to P. bachmaensis Karube, 2002 , described from central Vietnam, but P. robusta can be distinguished by the more curved superior appendages in lateral view and many minor differences in body maculations.

Figures

FIGURES 1 – 9. Planaeschna robusta sp. nov., holotype male (1 – 2, 5 – 8) and paratype female (3 – 4, 9): (1) body in lateral view; (2) head in frontal view; (3) head in frontal view; (4) body in lateral view; (5) appendages in dorsal view; (6) appendages in lateral view; (7) vesica spermalis in lateral view; (8) vesica spermalis in ventral view; (9) ovipositor.