Psenulus pallens, 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/08453112-8D76-481C-B958-02AEC71AD76E
taxon LSID	lsid:zoobank.org:act:08453112-8D76-481C-B958-02AEC71AD76E
treatment provided by	Journal of Hymenoptera Research by Pensoft
scientific name	Psenulus pallens
status	sp. nov.

Treatment

Psenulus pallens sp. nov.

Figs 4F-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 , 17F View Figure 17 , 18K, L View Figure 18 , 19K, L View Figure 19 , 20F View Figure 20 , 21F View Figure 21 , 22A-D View Figure 22

Diagnosis.

Psenulus pallens sp. nov. is readily distinguishable from most other species of its genus by its remarkably light coloration with black patches restricted as described below (Figs 4F View Figure 4 , 5F View Figure 5 , 22A-22D View Figure 22 ). From other similarly light-coloured species, it differs from P. lamprus van Lith, 1972 of Sulawesi by its less reticulated propodeum with polished area dorsally (Figs 14F View Figure 14 , 15F View Figure 15 ); in the female of the latter (the male is unknown), the back and most of the sides of the propodeum are densely and coarsely reticulate. The female of P. pallens also differs from P. lamprus in its cluster of denticles on the apex of hind tibia (Fig. 18K View Figure 18 ) as opposed to three reddish spines in the latter. It shows also considerable difference in the shape of the ventral clypeal margin (Figs 20F View Figure 20 , 21F View Figure 21 ) with that of similarly coloured P. lamprus and P. interstitialis , the latter two with small teeth, reduced to denticles and no emargination in-between. Psenulus impressus van Lith, 1976 of Luzon has the episternal sulcus foveolate. Psenulus singularis van Lith, 1962 also from Luzon has a distinctly shaped clypeus with the median section of the ventral margin bluntly protruding.

Material examined.

Holotype: China, Hong Kong • ♀; Mang Kung Wo ; 22°22'06"N, 114°15'12"E; 60 m a.s.l.; 18 May-01 Jun. 2019; C. Barthélémy leg.; Malaise trap, ref.: M416CHy1A; CAS GoogleMaps . Paratypes: China, Hong Kong • 2♀; Sam A Tsuen; 22°30'55"N, 114°16'16"E; 11-27 Dec. 2017; C. Taylor and U. Chang leg.; Malaise trap; HKU GoogleMaps • 1♀; Sam A Chung; 22°30'33"N, 114°16'20"E; 17-30 May 2018; ibid; HKU GoogleMaps • 1♀; Mang Kung Wo ; 22°22'06"N, 114°15'12"E; 60 m a.s.l.; 18 May-01 Jun. 2019; C. Barthélémy leg.; Malaise trap, ref.: M416CHy1B GoogleMaps • 1♀; ibid; 29 Jun.-13 Jul. 2019; ibid; ref.: M423CHy1; CBC GoogleMaps • 1♀; ibid; 05-19 Oct. 2019; ibid.; ref.: M443CHy1; CAS GoogleMaps • 1♀; ibid.; 19 Oct.-03 Nov. 2019; ibid.; ref.: M447CHy3; CAS GoogleMaps • 1♀; ibid.; 03-16 Nov. 2019; ibid.; ref.: M449CHy1; CAS GoogleMaps • 1♀; ibid.; 16-30 Nov. 2019; ibid.; ref.: M453CHy1; CBC GoogleMaps • 2♀; ibid.; 14-28 March 2020; ibid.; refs: M477CHy1A and 1B; CBC GoogleMaps • 1♀; ibid.; 11-25 Apr. 2020; ibid.; ref.: M483CHy1; CBC GoogleMaps • 1♂; Pak Sha O; 22°26'59"N, 114°19'04"E; 70 m a.s.l.; 15-29 Sep. 2018; ibid.; ref.: M368CHy1; CBC GoogleMaps • 1♀; ibid; 24 Aug. 07- Sep. 2019; ibid; ref.: M434CHy5; CBC GoogleMaps • 1♀; ibid.; 21 Sep.-05 Oct. 2019; ibid.; ref.: M440CHy4; CBC GoogleMaps • 1♀; ibid.; 28 Mar.-11 Apr. 2020; ibid.; ref.: M480CHy1; CBC GoogleMaps .

Standard ratios.

Males (n = 1): L = 4.6 mm; CR = 1.35; OOR = 0.46; FLR = 1.13; FRR = 0.59; MR = 1.65; OMR = 0.94; PR = 0.81; PFR = 0.81. Females (n = 16): L = 4.9-6.0 mm (mean = 5.45 mm); CR = 1.22-1.42 (mean = 1. 32); OOR = 0.47-0.65 (mean = 0.58); FLR = 1.22-1.67 (mean = 1.38); FRR = 0.42-0.63 (mean = 0.58); MR = 1.33-1.77 (mean = 1.55); OMR = 0.83-0.97 (mean = 0.89); PR = 0.82-1.29 (mean = 1.08); PFR = 0.75-0.97 (mean = 0.85).

Description.

Male: Antenna without tyloids. Clypeus (Fig. 21F View Figure 21 ) with two well-developed ventral teeth separated by triangular emargination, remainder of clypeal margin straight. Subantennal carina well developed; interantennal carina narrow, not broadened dorsally (Fig. 7F View Figure 7 ). Mesosoma mostly polished, mesoscutum lightly and minutely punctate (Fig. 11F View Figure 11 ), punctures very sparse elsewhere on mesosoma; prescutal sutures short, extending shortly beyond anterior level of tegula; episternal sulcus simple (Fig. 13F View Figure 13 ); propodeal enclosure with several pairs of longitudinal carinae; rear of propodeum (Fig. 15F View Figure 15 ) dorsally smooth, ventrally and laterally coarsely reticulate with reticulations encroaching on posterior part of side of propodeum. Petiole subcylindrical, T1 relatively low (Fig. 5F View Figure 5 ). Fore wing (Fig. 19L View Figure 19 ) with first recurrent vein more or less interstitial with first and second submarginal cells, second recurrent vein meeting third submarginal cell at about one-eighth of cell length from base.

Head black with silvery appressed pubescence (Figs 7F View Figure 7 , 9F View Figure 9 ); antenna with scape, pedicel and base of flagellum ventrally yellow, dorsum and terminal segments of flagellum black; mandible yellow with black tip. Mesosoma and legs mostly yellow, hind legs reddish from trochanter to tarsus, the following black: three small spots on mesoscutum, along posterior margin of mesoscutum and scutellar groove; mesosternum, encroaching onto base of mesopleuron; propodeal enclosure posteriorly. Petiole basally yellow, becoming reddish apically; remainder of metasoma reddish.

Female: Clypeus with small ventral teeth separated by shallow emargination (Fig. 20F View Figure 20 ). Subantennal carina distinct but not protruding beyond pubescence (Fig. 6F View Figure 6 ). Mesosoma mostly polished, mesoscutum lightly and minutely punctate (Fig. 11F View Figure 11 ), punctures very sparse elsewhere on mesosoma; prescutal sutures short, extending shortly beyond anterior level of tegula; episternal sulcus simple (Fig. 13F View Figure 13 ); mesopleural suture narrowly foveolate (Fig. 12F View Figure 12 ); propodeal enclosure with several pairs of longitudinal carinae; propodeum (Fig. 14F View Figure 14 ) polished and impunctate posteriorly and laterally, coarse reticulations restricted to marginal ridge along transition between posterior and lateral surfaces. Hind tibia with longitudinal cluster of dark denticles dorsobasally (Fig. 18K View Figure 18 ). Petiole subcylindrical, T1 relatively low (Fig. 5F View Figure 5 ). Pygidial plate narrow, delineated by distinct posteriorly parallel carinae (Fig. 16F View Figure 16 ). Fore wing (Fig. 19L View Figure 19 ) with first recurrent vein more or less interstitial with first and second submarginal cells, second recurrent vein meeting third submarginal cell at about one-eighth of cell length from base.

Head black with silvery appressed pubescence (Figs 7F View Figure 7 , 9F View Figure 9 ); antenna with scape, pedicel and base of flagellum ventrally yellow, dorsum and terminal segments of flagellum black; mandible yellow with black tip. Mesosoma and legs mostly yellow, hind legs reddish from trochanter to tarsus, amount of black coloration on mesosoma varying from almost entirely absent with only black marks on scutellar groove and mesosternum (including base of mesopleuron) remaining to slightly more extensive than in male with black marks also present anteroventrally on epicnemium, on lower half of metapleuron, and over entire propodeal enclosure. Petiole basally yellow, becoming reddish apically; remainder of metasoma reddish.

Etymology.

From the Latin for ‘pale’, in reference to this species’ distinctive coloration.

Notes.

Because of its marked differences with other known lightly coloured Psenulus we have concluded that this is a new species. We have collected females that show a great deal of discoloration and are even paler than the holotype, with hardly any black at all, save for a reduced band at intersection of the mesoscutum and scutum (Fig. 22B View Figure 22 ) and the head (Fig. 22A, B View Figure 22 ).

This species has been consistently collected at Mang Kung, the site with the highest anthropogenic disturbance, and was also found in mangroves (13.6% occurrence). It has the second longest (after P. continentis ) recorded activity period, spanning from March (W10) to December (W50).