Parabaeus nasutus van Noort, 2021

van Noort, Simon, Lahey, Zachary, Talamas, Elijah J., Austin, Andrew D., Masner, Lubomir, Polaszek, Andrew & Johnson, Norman F., 2021, Review of Afrotropical sceliotracheline parasitoid wasps (Hymenoptera, Platygastridae), Journal of Hymenoptera Research 87, pp. 115-222 : 115

Parabaeus nasutus van Noort sp. nov.

Figs 25 , 26

Material examined.

Holotype: South Africa • ♀; Northern Cape, Swaarweerberg, Vredehoek Farm ; 1613 m; 32°26.387'S, 20°34.501'E; 29 July-30 September 2010; S. van Noort; Yellow pan trap; Roggeveld Shale Renosterveld; SWA09-SUC1-Y05; SAM-HYM-P040757 (SAMC).

Paratypes: South Africa • 3♂♂, data as for holotype, except for 31 March-29 July 2010; SWA09-SUC1-Y04; SAM-HYM-P040756a-c (SAMC) .

Excluded from type material.

South Africa • 1♀; Western Cape, Gamkaberg Nature Reserve; 33°39.941'S, 21°53.505'E; 315 m; 19 Feb-30 Mar 2010; S. van Noort; Yellow pan trap; Gamka Thicket; GB09-SUC1-Y28; SAM-HYM-P093813 (SAMC).

Description.

Female body length: 0.84 mm. Colour of head, metasoma, antennae and fore and mid legs brown; mesosoma and hind legs yellow-brown.

Head as wide as long. Much wider than mesosoma, fractionally narrower than width of metasoma; in dorsal view moderately transverse; clypeus produced into flattened volcano-shaped, nasute-like process with central fovea ringed by a carina; malar sulcus present; frons convexly rounded; occiput vertical, mostly hidden by mesosoma; occipital carina not visible dorsally, not reaching to posterior margins of eyes or lateral ocelli; lateral ocelli connected by hyperoccipital carina forming a sharp dorsal delimitation between occiput and vertex; ocelli forming an obtuse triangle, POL>LOL; in anterior view frons 0.6 × width of head; subocular carina absent; gena wide; head covered with coriaceous sculpturing; antennal segments short and robust, clava 2.5 × as long as wide.

Mesosoma. Robust, 0.8 × width of metasoma, as long as wide; in dorsal view pronotum only visible as narrow strip around anterior margin, pronotal collar with posteriorly orientated, raised, medial bifurcated projection; mesoscutum convexly rounded, posterior margin strongly elevated, with scutellum forming dorsal plateau defined by darker, toothed ellipsoidal carina; posterior face abruptly declivitous; in lateral view pronotal spiracle seen as a small toothed bump at posterodorsal corner of pronotum; tegula absent; mesopleural carina absent; mesopleural carina present; dorsal mesosoma imbricate with associated posteriorly facing setae; pronotum imbricate in dorsal half, smooth with longitudinal striations in ventral half of lateral face; mesopleuron smooth dorsally with longitudinal striations in ventral half; pronotum and mesopleuron fused; metapleuron and dorsolateral propodeum densely covered with fine setae.

Metasoma. In dorsal view oval in shape; anterior margin broad; T1 very narrow, densely setose laterally, base of metasoma without obvious foveate pits (although there are possibly two pits indicated by depressions that are obscured by setae); tergite 1 with bifurcate projecting medial plate; T2 composing virtually all dorsal metasoma; T3-T6 very narrow, strip-like, only seen in posterior view; anterior T2 faintly longitudinally coriaceous, smooth in posterior half, whole surface sparsely setose.

Male. As in females, except for clava, which is more elongate.

Diagnosis.

Parabaeus nasutus has the following unique morphological apomorphies: elevation of posterior section of mesoscutum and scutellum into a medial projection, which dorsally has a transversely ellipsoidal plateau formed by the scutellum with a 90 degree drop-off posteriorly; base of metasoma without obvious foveolate pits (although there are possibly two pits indicated by depressions that are obscured by setae); T1 with bifurcate projecting medial plate; pronotal collar with posteriorly projecting medial bifurcating raised plate; clypeus produced into dorso-ventrally compressed, volcano-shaped, nasute-like process with a central apical fovea ringed by a carina; occipital carina not visible dorsally. Although P. nasutus has a number of derived diagnostic characters, from a ground-plan perspective the species is morphologically similar to P. peckorum sharing the same squamate sculpturing with scattered posteriorly projecting setae on the dorsal mesosoma, and dense setose patches on the metapleuron, dorsolateral propodeum and T1. Colour is, however, different from P. peckorum , which has a dark brown to black body with lighter brown antennae and legs, and dense white pubescence at the mesosomal-metasomal boundary.

Etymology.

Named for the exceptional clypeal modification into a nasute-like process. Latin adjective.

Distribution.

South Africa.

Comments.

We suspect that the central fovea ringed by a carina that is terminally situated on the clypeal nasute-like process is olfactory in nature, potentially containing chemo-sensillae that may be involved in host location, although males also possess this adaptation, so possibly it is involved in mate recognition. It is likely that the species lives in the leaf-litter habitat and probably attacks insect or arachnid eggs.

The single female from Gamkaberg Nature Reserve is uniformly orange-yellow, has a smoother mesopleuron, and weaker clypeal and posterior mesosomal protrusions. Overall, the surface sculpturing is also weaker. The specimen is smaller than the type series specimens and these differences may simply be related to the reduced size. There is, however, the possibility that this specimen represents a second closely related, undescribed species, but until further specimens are acquired to assess the degree of intraspecific variation this specimen is considered to belong to P. nasutus , but it is excluded from the type material.

Figures

Figure 25. Parabaeus nasutus van Noort sp. nov. female holotype (SAMC) (SAM-HYM-P 040757) A habitus, lateral view B habitus, dorsal view C head, mesosoma, lateral view D head, mesosoma, dorsal view E head, anterior view (inset: data labels) F habitus, ventral view.

Figure 26. Parabaeus nasutus van Noort sp. nov. female holotype (SAMC) (SAM-HYM-P 040757) A head, antenna, ventrolateral view B cheek, clypeus, mandibles ventrolateral view C toruli, clypeus, mandibles, ventral view D mesoscutum, propodeum, dorsal view E mesosoma, anterior metasoma, dorso-lateral view F scutellum, propodeum, metasoma, dorsal view.