Parabaeus Kieffer, 1910

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 Kieffer, 1910

Figs 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27

Parabaeus Kieffer, 1910: 294 (original description). Type: Parabaeus ruficornis Kieffer, by monotypy and original designation); Kieffer 1910: 100, 104 (description, list of species, keyed); Kieffer 1912: 86 (description); Kieffer 1912: 53 (redescribed as new); Dodd 1914: 59 (keyed); Kieffer 1926: 132, 133 (description, keyed); Brues 1940: 72 (description, comparison of recent and amber species); Muesebeck and Walkley 1956: 379 (citation of type species); De Santis 1971: 47 (emendation of diagnosis, key to species); Masner 1976: 67 (transfer to Inostemmatinae ); De Santis 1980: 311 (catalogue of species of Brazil); Masner and Huggert 1989: 96 (description, species list); Austin 1990: 647 (key to species of Old World, structure of mesosoma); Carpenter 1992: 471 (fossil references); Vlug 1995: 44 (catalogued, catalogue of world species); Austin and Field 1997: 53, 68 (structure of ovipositor system, discussion of phylogenetic relationships); Loiácono and Margaría 2002: 555 (catalogue of Brazilian species); Talamas and Buffington 2015: 9 (fossil in Dominican amber); Lahey, et al. 2019c: 76 (keyed).

Diagnosis.

Body shape variable, from stocky and highly convex to elongate, spindle-like. All Old World species are apterous, as are the described Neotropical species with some undescribed New World species being micropterous or full-winged. Mostly yellow or light brown. Posterior ocellus contiguous with inner orbit; ocellar triangle high. Cheek and postgena with deep longitudinal excavation for housing of scape. Antennal clava of both sexes ovoid, 4-merous. Mesosoma of flightless species subrectangular, with most sclerites fused. Fore wing (when present) with short rudiment of submarginal vein without apical knob. Metasoma highly convex both dorsally and ventrally. T1 fused with T2, and S1 with S2, into solid sclerite; felt fields absent from S2 ( Masner and Huggert 1989).

Species richness in the Old World.

Parabaeus abyssus Austin, 1990 (Australia) (Fig. 20 )

Parabaeus africanus Austin, 1990 (Malawi)

Parabaeus armadillus Austin, 1990 (South Africa) (Figs 21 - 24 )

Parabaeus austini Buhl, 2011 (Tanzania)

Parabaeus brevicornis Buhl, 2011 (Tanzania)

Parabaeus nasutus van Noort, sp. nov. (South Africa) (Figs 25 , 26 )

Parabaeus papei Buhl, 2011 (Tanzania)

Parabaeus peckorum Austin, 1990 (South Africa)

Parabaeus quasimodus Austin, 1990 (Kenya)

Parabaeus ruficornis Kieffer, 1910 (Seychelles) (Fig. 27 )

Distribution.

Afrotropical: Kenya, Madagascar, Malawi, Seychelles, South Africa, Tanzania ( Kieffer 1910; Austin 1990; Buhl 2011). Australasia: Australia. Neotropical: Argentina, Brazil, Colombia, Costa Rica, Dominican Republic, French Guiana, Mexico, Panama, USA (Florida), Venezuela ( Masner and Huggert 1989; Vlug 1995).

Biology.

Unknown. Predicted to be living near the ground, possibly as leaf-litter inhabitants ( Austin 1990). A number of specimens have subsequently been collected from canopy fogging sampling in Tanzania ( Buhl 2011), suggesting that they are far more mobile than previously assumed. Species from these fogging samples are likely to be associated with the rich epiphyte, micro-habitat present in the canopy of Afromontane forest.

Comments.

The Old World species are all apterous, as are the described Neotropical species: P. lenkoi de Santis, 1970 (Brazil) and P. kiefferi de Santis, 1970 (Argentina), but a number of New World species are known that are also micropterous or fully winged ( Masner and Huggert 1989). The Angolan species, P. machadoi Risbec, 1957 is in fact a species of Baeus Haliday (= Angolobaeus Kozlov) ( Kozlov 1970; Masner 1976). There is a described fossil species, P. pusillus Brues, 1940, from Eocene-Oligocene Baltic amber ( Brues 1940) and an undescribed species known from Oligocene-Miocene Dominican amber ( Talamas and Buffington 2015).

Sexual dimorphism is slight in some species with morphological differences only apparent in the shape of the antennal club ( Austin 1990), whereas other species have a metasomal horn developed on T1 in females, presumably to accommodate the ovipositor ( Austin 1990). Parabaeus ruficornis and P. peckorum are only known from males, and it is thus unclear as to whether the respective females will have a metasomal horn or not. Parabaeus peckorum belongs to the P. armadillus species-group, which does not have a metasomal horn in the females, whereas P. ruficornis belongs to the P. quasimodus species-group and hence is predicted to have a horn in females. Parabaeus nasutus sp. nov. belongs to the P. armadillus species-group.

There are two apparent species-groups in the Afrotropical region defined by the presence or absence of a hyperoccipital carina. We predict that these two groups will be further supported by the presence or absence of a metasomal horn in females, once both sexes of the known species are discovered.

Parabaeus armadillus species-group ( P. armadillus , P. nasutus , P. peckorum )

Hyperoccipital carina present.

Sexual dimorphism slight, females without metasomal horn on T1.

Absence of a sulcus between the lateral pronotum and mesopleuron.

Parabaeus quasimodus species-group ( P. africanus , P. austini , P. brevicornis , P. papei , P. quasimodus , P. ruficornis )

Hyperoccipital carina absent.

Sexual dimorphism strong, females with metasomal horn on T1 that is developed to varying degrees in size.

Sulcus between the lateral pronotum and mesopleuron present.

The only other described Old World species, the Australian P. abyssus falls into its own species-group, sharing characters across the two Afrotropical species-groups (hyperoccipital carina absent, but no metasomal horn on T1 in females) and the Neotropical species-group, which has armature (points, spikes or truncate projections) on the posterior or posterolateral margin of the propodeum, and these are also present in P. abyssus ( Austin 1990).

The following key includes diagnostic characters enabling both sexes to be keyed out where known. Males of four species ( P. austini , P. brevicornis , P. quasimodes , P. papei ) with metasomal horns in females are as yet unknown, and hence will not be identifiable using the current key configuration.

Figures

Figure 20. Parabaeus abyssus female paratype (NHMUK) A habitus, dorsal view B habitus, lateral view C head, anterior view D data labels.

Figure 21. Parabaeus armadillus female holotype (NHMUK) A habitus, dorsal view B habitus, lateral view C head, anterior view D data labels.

Figure 22. Parabaeus armadillus female (SAMC) (SAM-HYM-P 031787) A habitus, lateral view B habitus, dorsal view C head, anterior view D data labels.

Figure 23. Parabaeus armadillus male (SAMC) (SAM-HYM-P 037510 A) A habitus, lateral view B habitus, dorsal view (inset: data labels) C head, mesosoma, lateral view D head, mesosoma, dorsal view.

Figure 24. Parabaeus armadillus male (SAMC) (SAM-HYM-P 037510 A) A head, anterior view B head, antenna and legs, anterior view C metasoma, lateral view D metasoma, dorsal view.

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.

Figure 27. Parabaeus ruficornis female holotype (NHMUK) (B. M. TYPE HYM. 9.399) A habitus, dorsal view B habitus, lateral view C head, anterior view D data labels.