Psomizopelma fuscum Gibson 2018, n. sp.
Creators: name: Gibson, Gary A. P.
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Eupelmidae
Psomizopelma
Psomizopelma fuscum

description: Psomizopelma fuscum n. sp.
Figs 32–40
Type material. Holotype ♀ (CNC). DOMINICAN REPUBLIC: | La Vega, around | Manabao, 900m, SS | 21.I.1989, L. Masner | riparian habitat, SS / HOLOTYPE ♀ | Psomizopelma | fuscum Gibson. Holotype pointmounted; entire; uncontorted.
Etymology. Derived from the Latin word fuscus, “dark”, in reference to the generally dark head and gaster, which differentiates the holotype from females of P. brachypterum.
Description. FEMALE (habitus: Figs 32, 33). Length about 4.5 mm. Head (Figs 32–35) uniformly dark brown except lower face, particularly clypeus laterally and apically, slightly paler, more yellowish-brown (Fig. 35). Labiomaxillary complex with palps dark brown. Antenna (Fig. 36) with scape graduating from yellowish ventrally to brownish-yellow dorsally, but conspicuously paler than flagellum and with whitish setae; pedicel and flagellum dark brown. Mesosoma (Figs 32, 33) dark brown except mesoscutal lateral flange paler, yellowish-brown, and ventral and posterolateral margins of pronotal panel whitish. Legs (Figs 32, 33) similarly dark brown as mesosoma. Gaster (Figs 32, 33, 39) dark brown except Gt1 posterolaterally and Gt2 laterally white (white transverse band visible basally on Gt 3 in Figs 32, 39 is membrane that is normally concealed, the two tergites being separated as a result of critical point drying), and all sternites white except for hypopygium.
Head with face (Fig. 34) almost uniformly punctate-reticulate and completely setose except scrobes above toruli and small, subcircular bare region dorsally on interantennal prominence near dorsal limit of bare part of scrobes; eyes and face with white hairlike or at most very slender, elongate-lanceolate setae except for brownish hairlike setae on clypeus and lower face lateral of clypeus; scrobal depression comparatively shallow and small, delimiting broad parascrobal region (Fig. 35), minimum width of parascrobal region between torulus and lower inner orbit at least as wide as width of torulus and 0.6× distance between toruli; malar space about 0.33× eye height; OOL: POL: LOL: MPOD = 33: 35: 24: 15; interorbital distance 0.5× head width. Antenna (Fig. 36) with scape comparatively slender, about 5× as long as greatest width, with ventral margin almost straight so subequal in width over most of length though slightly narrower basally; clava slightly longer than combined length of apical 5 funiculars.
Brachypterous (Figs 32, 38); fore wing about 4.6× as long as maximum width and extending only to about base of gaster (Fig. 38), at most slightly beyond level of petiole; dark brownish-infuscate, and membrane and venation similarly, densely covered with dark brown, slightly lanceolate setae. Mesonotum similarly punctate-reticulate as head, with dark setae; scutellum conspicuously elongate-oval (Fig. 38), almost 3× as long as wide and about 1.5× maximum width of scutellar-axillar complex. Prepectus sparsely setose (Fig. 37). Acropleuron isodiametric reticulate anteriorly and posteriorly, though reticulations smaller posteriorly, and with much smaller, more elongate-punctate reticulations just beyond setae. Metapleuron bare; metasternum not visible because of position of middle leg, but presumably setose. Front leg (Fig. 37) with femur strongly expanded over about apical half such that ventral margin conspicuously sinuate and dorsal length only about 2.8× maximum width; tibia also conspicuously compressed such that only about 3.6× as long as maximum width at about midlength. Hind leg (Figs 33, 40) with coxa setose at least dorsoapically and narrowly ventrolongitudinally, but apparently with only a few setae dorsobasally (surface mostly concealed by femur); femur slightly expanded over about apical one-third, the more enlarged region delimited basally by slight notch on dorsal margin; tibia conspicuously compressed with dorsal margin more or less uniformly curved, but ventral margin with notch at about midlength; basitarsomere very slightly, inconspicuously compressed. Propodeum with foramen sinuately incurved to anterior margin.
Metasoma with petiole obviously transverse, lunate. Gaster dorsally (Fig. 39) with Gt1 and Gt2 more or less meshlike reticulate, but subsequent tergites more irregular rugulose-reticulate; Gt1 mostly bare dorsally, but Gt2 and subsequent tergites densely setose with posteriorly directed setae, the setae dark dorsally on Gt2, Gt3 and basal half of Gt4, but paler brownish dorsally on subsequent tergites to whitish laterally.
MALE. Unknown.
Distribution. Neotropical: Dominican Republic.
Remarks. The only known female of P. fuscum from Dominican Republic is very similar to females of P. brachypterum from the Florida Keys. It is slightly larger but otherwise is differentiated by one setal and a few colour features. Although the exact number of prepectal setae is uncertain for the P. fuscum holotype (left prepectus with at least four setae, but right prepectus with only one visible seta) (Fig. 37: pre), females of all other species, including P. brachypterum, have a bare prepectus. Colour features that differentiated P. fuscum from P. brachypterum include Gt3 being entirely brown (Fig. 33, note clarification given above in description), the mesopectus and acropleuron being uniformly dark brown (Fig. 33), the fore wing having entirely dark brown setae (Fig. 38), the ovipositor sheaths being entirely brown (Fig. 33), and the scape being obviously paler than the uniformly dark flagellum (Fig. 36). Further, the metacoxae of all examined P. brachypterum females are more extensively and conspicuously setose than for the P. fuscum holotype, with conspicuous setae dorsobasally and across the outer surface apically. Examined P. brachypterum females also have quite a distinct notch on the dorsal margin of the metafemur at about its midlength (Fig. 18) so the dorsal margin is curved both in its basal and apical halves, whereas the P. fuscum holotype has the dorsal margin of the metatibia essentially uniformly curved but has a distinct notch on the ventral surface at about midlength (Fig. 40). More specimens of at least P. fuscum are necessary to accurately determine intraspecific variation and the differential value of all of the features. It is unknown what features might differentiate P. fuscum and P. brachypterum males because the differential features of females likely are not exhibited by males.
description: Published as part of Gibson, Gary A. P., 2018, The species of Psomizopelma Gibson (Hymenoptera: Eupelmidae), pp. 73-91 in Zootaxa 4444 (1) on pages 83-85, DOI: 10.11646/zootaxa.4444.1.5, http://zenodo.org/record/1309488