Review of Psenulus species (Hymenoptera, Psenidae) in the Hong Kong SAR, with description of three new species Author Taylor, Christopher K. School of Biological Sciences, The University of Hong Kong, Hong Kong, China & School of Molecular and Life Sciences, Curtin University, Perth, Australia & School of Animal Biology, University of Western Australia, Perth, Australia Author Barthelemy, Christophe https://orcid.org/0000-0002-8234-6237 Sai Kung, Hong Kong, China chb99@netvigator.com Author Chi, Roy Cheung Shun School of Biological Sciences, The University of Hong Kong, Hong Kong, China Author Guenard, Benoit School of Biological Sciences, The University of Hong Kong, Hong Kong, China text Journal of Hymenoptera Research 2020 2020-10-30 79 169 211 http://dx.doi.org/10.3897/jhr.79.55832 journal article http://dx.doi.org/10.3897/jhr.79.55832 1314-2607-79-169 9AF2643B484E4367845E20772317FCFF 374E3FB4B427519099FE9EFD5B6AE61D 4255283 Psenulus ephippius sp. nov. Figs 4C-4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17C , 18E, F , 19E, F , 20C , 21C Diagnosis. In its entirely black mesosoma (Figs 4C , 5C ) with a polished horizontal area behind the propodeal enclosure (Figs 14C , 15C ), narrow interantennal carina (Figs 6C , 7C ), and indistinct pygidial plate (Figs 16C , 17C ), 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 . Figure 13. Males, mesopleuron 13A P. carinifrons rohweri 13B P. continentis 13C P. ephippius sp. nov., paratype 13D P. gibbus sp. nov.; paratype 13E P. maculatus maculatus 13F P. pallens sp. nov., paratype. 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. Barthelemy leg.; Malaise trap , ref.: M407. C.Hy. 2; CAS . Paratypes : China , Hong Kong • 1♂ ; ibid.; 31 Mar. -14 Apr. 18; ibid.; ref.: M339. C.Hy. 4; CBC • 1♀ ; ibid.; 28 Apr.-12 May 2018 ; ibid.; ref.: M345CHy4; [specimen destroyed at mounting] • 1 ♀ ; ibid; 20 Apr.-04 May 2019 ; ibid.; ref.: M411. C.Hy. 2; CAS • 1♀ ; ibid.; 11 Apr.-25 May 2020 ; ibid.; ref.: M483. C.Hy. 3; CBC . 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 ) 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 ); 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 ); propodeum laterally and posteriorly coarsely reticulate, dorsally narrowly polished with very small and largely interspaced punctures (Fig. 15C ). Petiole subcylindrical; T1 swollen (Fig. 4C ). Fore wing (Fig. 19F ) 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 x ) of cell length from base. Head entirely black with appressed silvery pubescence (Figs 7C , 9C ); 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 ). 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 ). Female : Clypeus ventrally (Fig. 20C ) 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 ); prescutal sutures short, not extending beyond anterior level of tegula; episternal sulcus and mesopleural suture narrowly foveolate along entire length (Fig. 12C ). Propodeum laterally and posteriorly weakly reticulate, dorsal half polished with very small and largely interspaced punctures (Fig. 14C ). Dorsal part of hind tibia, normal, no polished area and no small denticles dorsobasally (Fig. 18E ). Petiole subcylindrical; tergum I low (Fig. 5C ). Pygidial plate with very faint medial carina extending about half length of T6 (Fig. 16C ). Fore wing (Fig. 19F ) 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 x ) of cell length from base. Head entirely black with appressed silvery pubescence (Figs 7C , 9C ); 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 ). 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 ). 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). Figure 14. Females, propodeum in dorsal view 14A P. carinifrons rohweri 14B P. continentis 14C P. ephippius sp. nov., holotype 14D P. gibbus sp. nov.; holotype 14E P. maculatus maculatus 14F P. pallens sp. nov., holotype.