Eucharissa insolita, Heraty & Mbanyana & Van Noort, 2020

Heraty, John M., Mbanyana, Nokuthula & Van Noort, Simon, 2020, A new species of Eucharissa Westwood (Eucharitidae) from South Africa, with an evaluation of the importance of pupae for assessing relationships in these ant parasitoids, Journal of Hymenoptera Research 79, pp. 43-55 : 43

Eucharissa insolita sp. nov.

Figures 1-4 , 5-10

Diagnosis.

This species shares the following features with Eucharissa natalica Westwood: 16 antennal segments, flagellomeres of male with long dorsal rami, absence of a pronounced interantennal process, labrum transverse and hidden behind clypeus, hind tibia with one spur, and head and mesosoma dark blue. The major difference is the presence of basket-like, double-branched rami on all but the last flagellomere. This form of the antenna is most similar to E. stigmatica Westwood (cf. Westwood 1874, fig. XXVII 2a), but this other species has 19 flagellomeres. Compared to E. natalica , E. insolita has the mesoscutellar disc slightly longer than broad with the dorsal aspect flat in profile and on the same plane as the axillae, whereas in E. natalica the mesoscutellum is as long as broad, broadly rounded dorsally and elevated above the dorsal plane of the axillae ( Heraty 2002, fig. 141). As well, the eyes of E. insolita are smaller and separated by 2.5 × their height (versus 2.1 ×) and the basal gastral tergite has an even covering of micropunctuation. Other species of Eucharissa have 18 or more antennal segments.

Male. Length, 5.6 mm. Antenna dark brown; head, mesosoma, coxae, petiole, and most of gaster dark metallic blue; basal two-thirds of femora dark brown to black; apical gastral terga mostly brown; apex of femora, tibiae, and tarsi yellow; wings hyaline, venation brown.

Head 1.7 × as broad as high. Frons rugose and covered by long fine setae, vertex bare just lateral to ocelli; vertexal carina sharp and extending laterally to eye margin. Eyes separated by 2.5 × their height. Posterior genal margin carinate; malar space 0.8 × height of eye and concave. Scrobes broadly impressed, laterally with weak vertical carinae in line with outer torular margin, and single median vertical carina extending to torulus. Toruli separated by a narrow ridge but not noticeably pronounced. Tentorial pits strongly impressed, supraclypeal area not demarked, clypeal region nearly smooth with sparse long setae. Labrum transverse and hidden behind clypeus, ventral margin with 5 tuberculate digits, each with a long seta that extends beyond clypeal margin. Mouthparts reduced, palpi absent. Antenna with 16 segments; scape almost reaching median ocellus; pedicel rounded and smooth; length of flagellum 1.3 × height of head, F2 0.4 × as long as broad basally, F2 as long as F3, following segments progressively longer along axis, F2-F10 with long paired flattened rami, decreasing in length apically, no distinct clava, F14 spatulate; flagellum pilose; multiporous plate sensilla not apparent.

Mesoscutum rugulose, about as long as broad and covered with long fine decumbent setae; notauli vaguely impressed and reaching transscutal articulation. Mesoscutellum and axilla rugose-areolate; mesoscutellar disc medially impressed and slightly longer than broad, dorsally flat in profile and on same plane as axilla, axillula lacking; frenum separated from mesoscutellum by non-carinate sulcus; entire surface of mesoscutellum with long fine decumbent setae. Propodeum broadly rounded, rugose-areolate, densely setose; propodeal spiracle circular with long narrow ventral excision of propodeum about as long as spiracle diameter. Mesopleuron rugose-areolate, lower mesepimeron mostly bare. Prepectus coarsely rugose-alveolate, upper half slightly swollen, distinguished from pronotum by shallow furrow. Hind coxa mostly smooth and shining, all coxae and femora with long fine setae; protibial spur thin and acuminate; one metatibial spur. Wings subtriangular; fore wing 2.9 × as long as broad; venation complete (not interrupted); postmarginal vein 0.4 × as long as marginal vein; stigmal vein about twice as long as broad and slightly recurved distally; entire wing with sparse short setae, marginal fringe absent. Hind wing with microsetae and sparse marginal fringe.

Petiole 3.0 × as long as broad and 1.7 × as long as the hind coxa, smooth with mediolateral patch of long setae, ventrally with thin medial sulcus. Gastral tergites smooth with sparse long recumbent setae and scattered micropunctuations; no tergal scar on Gt1. First gastral sternite (Gs1) smooth without any constriction. Gs9 broadly rounded apically and setose. Aedeagus stout, digitus discoidal with short marginal spines, paramere broad with two apical setae. Cerci absent.

Female. Unknown.

Immatures.

First instar (from exuvium, without head capsule, Fig. 9 ). Terga TI and TII fused dorsally, with 4 pairs of setae, ventrolateral pair as stout short spines; tergopleural line (tpl) present on TII to TVIII; relative to tpl, TIII with three pairs of setae, one dorsal pair, one posterior pair just lateral to tpl, and one pair on ventral margin, posteroventral corner acuminate; TIV with one dorsal pair of setae just medial to tpl, posteroventral margin rounded; TV with one dorsal pair of setae and one stout ventral pair; TVI as in TIV, but spine more robust, length exceeding width of tergum; TVII with posterior margin lateral to tpl with two acuminate posterior processes and one pair of ventral setae; TVIII similar to TVII but without setae and posterior margin medial to tpl crenulate; TIX with posteroventral margin long, spine-like and reaching to apex of TXII; TX tubular with crenulate posterior margin; TXI with broad posteromedial extension covering part of TXII; TXII with acute emarginate apex; cerci short and not reaching TXII apex.

Second instar (Fig. 10 ). Length 3.9 mm. Hymenopteriform in shape. Spiracles present on body segments 1-7; body segments very finely tuberculate. Planidial exuvium attached to ventral thoracic region.

Pupa (from detached exuvium, antennal exuvium still attached to adult, Figs 5-8 ). Able to discern distinct ocellar horns (Fig. 7 , och), a ventrolateral process (vlp2), and a bladder-like dorsolateral process on gaster (dlp2); see Heraty et al. (2015) for a full description of each structure. A dorsal mesoscutellar swelling could not be observed, but may be present. A darkly pigmented tergal bar on the basal terga (as found in Schizaspidia ) was not observed on the exuvium; notably the corresponding tergal scar was also not found on the adult, so this structure is considered to be absent in this species.

Holotype.

South Africa: Mpumalanga: 2km E R532 on God’s Window sideroad, 1495m, 24°54'32"S, 30°51'38"E, 07 Dec 2016, N. Mbanyana & S. van Noort; nest #48 found at the base of a grass tussock with soil and gravel around the entrance; ex Bothroponera granosa (1 ♂, SAM-HYM-P095050); deposited in SAMC; ant host voucher (SAM-HYM-C028101; SAMC). Exuvium and host remains mounted on same point. Exuvium of planidium from same pupa mounted on slide (SAM-HYM-P095051; SAMC).

Material examined.

One second-instar larva (SAM-HYM-P095052, SAMC): same locality as holotype, 08 Dec 2016, N. Mbanyana & S. van Noort; nest #59; raised hillock nest about 20cm high, fish tank gravel [= quartz gravel composed of evenly sized small stones] excavated and brought to surface; brood collected at about 5cm below the ground level, workers down to 30cm below; ex Bothroponera granosa (ant voucher SAM-HYM-C028104). Exuvium of planidium from same larva mounted on slide (SAM-HYM-P095053; SAMC) .

Etymology.

From the Latin insolitus for unusual or strange; gender feminine.

Figures

Figures 1 - 4. Eucharissa insolita sp. nov., male 1 head and mesosoma, anterior 2 habitus, lateral 3 lower face, frontal 4 habitus, dorsal.

Figures 5 - 10. Eucharissa insolita sp. nov. 5 - 8 male: 5 head and mesosoma in place in cocoon 6 adult in place in cocoon 7 exuvium of body and host ant remains 8 exuvium cap from face and antenna, anterior 9 planidial exuvium taken from last-instar larva 10 last instar larva, lateral. Abbreviations: dlp 2, dorsolateral process; T, tergum.