Psenulus ephippius, Taylor & Barthélémy & Chi & Guénard, 2020

Taylor, Christopher K., Barthelemy, Christophe, Chi, Roy Cheung Shun & Guenard, Benoit, 2020, Review of Psenulus species (Hymenoptera, Psenidae) in the Hong Kong SAR, with description of three new species, Journal of Hymenoptera Research 79, pp. 169-211 : 169

publication ID	https://dx.doi.org/10.3897/jhr.79.55832
publication LSID	lsid:zoobank.org:pub:9AF2643B-484E-4367-845E-20772317FCFF
persistent identifier	https://treatment.plazi.org/id/1FA5CE44-CE84-4CEA-A73C-D53257CDF1CF
taxon LSID	lsid:zoobank.org:act:1FA5CE44-CE84-4CEA-A73C-D53257CDF1CF
treatment provided by	Journal of Hymenoptera Research by Pensoft
scientific name	Psenulus ephippius
status	sp. nov.

Treatment

Psenulus ephippius sp. nov.

Figs 4C-4 View Figure 4 , 5 View Figure 5 , 6 View Figure 6 , 7 View Figure 7 , 8 View Figure 8 , 9 View Figure 9 , 10 View Figure 10 , 11 View Figure 11 , 12 View Figure 12 , 13 View Figure 13 , 14 View Figure 14 , 15 View Figure 15 , 16 View Figure 16 , 17C View Figure 17 , 18E, F View Figure 18 , 19E, F View Figure 19 , 20C View Figure 20 , 21C View Figure 21

Diagnosis.

In its entirely black mesosoma (Figs 4C View Figure 4 , 5C View Figure 5 ) with a polished horizontal area behind the propodeal enclosure (Figs 14C View Figure 14 , 15C View Figure 15 ), narrow interantennal carina (Figs 6C View Figure 6 , 7C View Figure 7 ), and indistinct pygidial plate (Figs 16C View Figure 16 , 17C View Figure 17 ), this species comes closest to the Psenulus crabroniformis species group as defined by van Lith (1962). However, the species assigned to that group, P. crabroniformis (Smith, 1858) of western Indonesia and P. philippinensis (Rohwer, 1921) of the Philippines, have a well-developed subantennal carina in the female (in contrast to the notably weak carina in the current species), and the first recurrent vein is received by the first submarginal cell as opposed to being interstitial to first and second submarginal cell. Psenulus crabroniformis further differs in having the antennal scape yellow whereas P. philippinensis possesses a pair of well-developed frontal tubercles (van Lith 1962), both absent in P. ephippius sp. nov. The new species also resembles P. decipiens van Lith, 1976 in overall coloration and lack of antennal tyloids in the male but the latter species has longer prescutal sutures, as long as the scutum, and the position of the first recurrent vein is as in P. crabroniformis and P. philippinensis .

Material examined.

Holotype: China, Hong Kong • ♀; Mang Kung Wo ; 22°22'06"N, 114°15'12"E; 60 m a.s.l.; 06-20 Apr. 2019; C. Barthélémy leg.; Malaise trap, ref.: M407. C.Hy. 2; CAS GoogleMaps . Paratypes: China, Hong Kong • 1♂; ibid.; 31 Mar. -14 Apr. 18; ibid.; ref.: M339. C.Hy. 4; CBC GoogleMaps • 1♀; ibid.; 28 Apr.-12 May 2018; ibid.; ref.: M345CHy4; [specimen destroyed at mounting] GoogleMaps • 1 ♀; ibid; 20 Apr.-04 May 2019; ibid.; ref.: M411. C.Hy. 2; CAS GoogleMaps • 1♀; ibid.; 11 Apr.-25 May 2020; ibid.; ref.: M483. C.Hy. 3; CBC GoogleMaps .

Standard ratios.

Males (n = 1): L = 7.00 mm; CR = 1.28; OOR = 0.89; FLR = 1.1; FRR = 0.79; MR = 1.58; OMR = 0.95; PR = 0.68; PFR = 1.18. Females (n = 3): L = 7.4-7.9 mm (mean = 7.7 mm); CR = 1.27-1.3 (mean = 1.29); OOR = 0.73-0.75 (mean = 0.73); FLR = 1.63-1.73 (mean = 1.66); FRR = 0.70-0.85 (mean = 0.80); MR = 1.49-1.77 (mean = 1.68); OMR = 0.89-0.9 (mean = 0.89); PR = 0.30-0.36 (mean = 0.34); PFR = 1.15-1.19 (mean = 1.17).

Description.

Male: Antenna without tyloids. Clypeus (Fig. 21C View Figure 21 ) with two blunt ventral teeth separated by a rounded emargination, remainder of clypeal margin more or less straight on the first two-fifths and terminated by a flattened lobe on the last two-fifths of the margin. Subantennal carina well developed; interantennal carina narrow, not broadened dorsally. Mesoscutum moderately punctate with small punctures separated by at least their own diameter (Fig. 11C View Figure 11 ); prescutal sutures short, not extending beyond anterior level of tegula; episternal sulcus broadly foveolate, mesopleural suture with small fovea on dorsal half; propodeal enclosure with marked fovea (Fig. 15C View Figure 15 ); propodeum laterally and posteriorly coarsely reticulate, dorsally narrowly polished with very small and largely interspaced punctures (Fig. 15C View Figure 15 ). Petiole subcylindrical; T1 swollen (Fig. 4C View Figure 4 ). Fore wing (Fig. 19F View Figure 19 ) with first recurrent vein interstitial or reaching second submarginal cell near base, second recurrent vein reaching third submarginal cell at about one-sixth (0.17 ×) of cell length from base.

Head entirely black with appressed silvery pubescence (Figs 7C View Figure 7 , 9C View Figure 9 ); antenna with scape dark brown, venter of pedicel and venter of flagellum of a lighter brown, dorsum of pedicel and remainder of flagellum dark brown; mandible black on the apical third and basal sixth, the remainder yellow. Mesosoma entirely black (Fig. 5C View Figure 5 ). Femurs, trochanters and coxae black, tibiae and tarsi light brown/yellow. Petiole mostly black, distally red/orange; remainder of gaster mostly reddish but T2-T5 and S3-S7 with large dark brown/black areas (Fig. 5C View Figure 5 ).

Female: Clypeus ventrally (Fig. 20C View Figure 20 ) with two blunt/rounded teeth, separated by a deep rounded emargination, the remainder of the clypeal margin forming a shallow concavity extending across half of margin and terminated on last third with a blunt lobe intersecting eye margin; dorsal margin flattened on central third of transverse length of clypeus, the remainder reaching ventral margin along a shallow convex line. Subantennal carina weak, extending about one-third of distance between interantennal carina and eye; interantennal carina narrow, not broadened dorsally. Mesoscutum moderately punctate with small punctures separated by at least their own diameter (Fig. 11C View Figure 11 ); prescutal sutures short, not extending beyond anterior level of tegula; episternal sulcus and mesopleural suture narrowly foveolate along entire length (Fig. 12C View Figure 12 ). Propodeum laterally and posteriorly weakly reticulate, dorsal half polished with very small and largely interspaced punctures (Fig. 14C View Figure 14 ). Dorsal part of hind tibia, normal, no polished area and no small denticles dorsobasally (Fig. 18E View Figure 18 ). Petiole subcylindrical; tergum I low (Fig. 5C View Figure 5 ). Pygidial plate with very faint medial carina extending about half length of T6 (Fig. 16C View Figure 16 ). Fore wing (Fig. 19F View Figure 19 ) with first recurrent vein interstitial or reaching second submarginal cell near base, second recurrent vein reaching third submarginal cell at about one-sixth (0.17 ×) of cell length from base.

Head entirely black with appressed silvery pubescence (Figs 7C View Figure 7 , 9C View Figure 9 ); antenna entirely dark brown/black. Mandible yellow on basal half and then gradually darkening to become black at the apex. Mesosoma entirely black (Fig. 5C View Figure 5 ). Femurs, trochanters and coxae black, tibiae and tarsi light brown/yellow except hind tibia dark brown/black. Petiole mostly black, distally red/orange; remainder of metasoma mostly reddish but T2-T5 and S3-S7 with large dark brown/black areas (Fig. 5C View Figure 5 ).

Etymology.

Species named as a toponomy in reference to the mountain facing the type locality, Ma On Shan or Horse Saddle Mountain in Chinese (ephippium = saddle in Latin).

Notes.

This species has only been recorded so far from one site in the SAR, at Mang Kung Wo which presents the highest anthropogenic disturbance of all our sampled sites. It remains uncommon, having only been recorded from five specimens since the beginning of continuous sampling at this site in March 2018. This species has apparently the shortest activity period of all Hong Kong Psenulus and is recorded from end of March (W13) to September (W37).