Cymosema Heraty & Burks, 2017

Burks, Roger A., Heraty, John M., Mottern, Jason, Dominguez, Chrysalyn & Heacox, Scott, 2017, Biting the bullet: revisionary notes on the Oraseminae of the Old World (Hymenoptera, Chalcidoidea, Eucharitidae), Journal of Hymenoptera Research 55, pp. 139-188 : 150-151

Cymosema Heraty & Burks gen. n. Figs 15-20 , 21-26 , 27

Type species.

Cymosema waterworthae Burks & Mottern sp. n.

Etymology.

Based on the Greek κύμα (kyma) for wave and referring to the sinuate transscutal articulation; gender feminine.

Discussion.

The two species in this group are each known from single specimens collected in Australia, both among the smallest known Eucharitidae . They differ from previously described species of Orasema by having a cylindrical ventrally fused petiole that tapers basally to the articulating condyle (Figs 20 , 25 ), reduced mouthparts (Figs 16 , 21 ), and advanced axillae (Figs 19 , 24 ). The mesoscutum and mesoscutellum are separated by a distinct transscutal articulation, but the sclerites are tightly associated and the axillae are advanced (thus somewhat resembling the state in Timioderus and Indosema ). Based on morphological (reduced anellus, reduced mouthparts, smooth head and mesosoma) and molecular evidence, they are the potential sister group of Indosema . The fore wing shape is unique within Eucharitidae , with the anterior leading edge of the fore wing anteriorly curved at the stigmal vein giving the wing an oval-shaped appearance (Fig. 27 ); in other Eucharitidae the wing margin beyond the stigmal vein is straight (Fig. 7 ). Male unknown.

Diagnosis.

Recognized from most Oraseminae by the sinuate closely associated transscutal articulation, minute discoidal anellus, reduced mouthparts that are at most bidentate and medially directed (not falcate), basally tapered petiole and elongate slightly curved ovipositor. Distinguished from other Old World genera by the head transverse in frontal view and mostly smooth (Figs 16 , 21 ); scrobal depression strongly impressed and forming weak parallel channels, but without dorsal foveae; dorsal occipital margin abrupt and rounded; funicle 7-segmented; mandibles, chisel-shaped and slightly broader than long or bidentate with both teeth projecting medially (not falcate as in other Eucharitidae ); labrum appears to be membranous and without digits; palpi greatly reduced; mesonotum appearing bare, at most with minute setae; mesoscutal lateral lobes entirely smooth or weakly reticulate laterally; frenum smooth; transscutal articulation sinuate and distinct but sclerites closely associated and appearing fused; callus bare; propodeal disc smooth (Fig. 20 ) or weakly reticulate with single median carina (Fig. 24 ); prepectus foveate and loosely articulated with pronotum ventrally (Fig. 18 ); fore wing with basal area and specular area evenly covered with minute setae, and anterior margin of fore wing disc curved at stigmal vein (Fig. 27 ); postmarginal vein short and about 1.5 × as long as stigmal vein; petiole base tapered and without transverse flange (Figs 20 , 25 ); petiole fused ventrally, basally tapering to condyle and without basal flange; acrosternite swollen and finely reticulate, antecostal sulcus not apparent, but a distinct transition to the smooth posterior region of Gs1; ovipositor long and slightly curved anteriorly (Fig. 26 ); first valvula with 3-4 lateral teeth and with a strong oblique subapical ridge.

Host association.

Unknown.

Distribution.

Two species. Australia (Queensland and Western Australia).

Figures

Figure 27. Cymosema waterworthae. Holotype female: fore wing. arrow points to end of postmarginal vein.

Figures 15 - 20. Cymosema capelina. Holotype female: 15 habitus, lateral 16 head, anterior 17 antennae, lateral 18 mesosoma, lateral 19 mesosoma, dorsal 20 propodeum and petiole, oblique dorsal. ax = axilla; F = flagellomere; md = mandible; pet = petiole; prp = propodeum; tsa = transscutal articulation.

Figures 21 - 26. Cymosema waterworthae. Holotype female: 21 head, anterior 22 antennae, lateral 23 mesosoma, lateral 24 mesosoma, dorsal 25 petiole, lateral 26 ovipositor. pet = petiole.

Figures 7 - 12. Australosema verghetta. Paratype female: 7 habitus, lateral 8 head, anterior 9 antennae, dorsal 10 mesosoma, dorsal; 11 propodeum and petiole, dorsal 12 mesosoma, lateral. acs = antecostal sulcus; apc = anterior petiolar carina; axlg = axiullar groove; cal = callus; F = flagellomere; frg = frenal groove; lpr = lateral propodeal disc; not = notaulix; SSS = scutoscutellar sulcus; tsa = transscutal articulation.