BELONOCNEMA TREATAE (MAYR, 1881)

(FIG. 2)

Dryorhizoxenus floridanus Ashmead, 1881, female, male, sexual generation, gall.

Belenocnema [sic!] treatae Mayr, 1881, female, sexual generation.

Material examined: Asexual generation – 12F ‘ USA: FL: Jacksonville Type 2813, USNM, Dryorhizoxenus floridanus ’; 6F ‘ USA:FL: E. Florida, USNM’; 1F ‘ USA:FL: LaBelle, IV-20–21, USNM’; 1F ‘ USA: FL: Tampa 14-4, USNM’; 1F ‘ USA: FL: Manatee Co., 111– 26, R. F. Tinker, USNM’; 5F ‘ USA: AL, Dauphin Island, 30.2504, -88.1325, 29/X/2016, Ott Lab, Q. virginiana ’; 2F ‘ USA: FL, Archbold Biol. Stn., 27.1846, -81.3521, 28/X/2016, Ott Lab, Q. virginiana ’; 5F ‘ USA: FL, Kissimmee River, 27.3780, -81.0968, 18/X/2016, Ott Lab, Q. virginiana ’; 5F ‘ USA: FL, Perry, 30.1161, -83.5895, 14/X/2015, Ott Lab, Q. virginiana ’; 5F ‘ USA: GA, Jekyll Island, 31.0174, -81.4297, 28/X/2016, Ott Lab, Q. virginiana ’; 3F ‘ USA: MS, Gautier, 30.3803, -88.6104, 28/X/2016, Ott Lab, Q. virginiana ’; 5F ‘ USA: NC, Fort Macon, 34.6951, -76.6862, 30/X/2016, Ott Lab, Q. virginiana ’; 5F ‘ USA: SC, Charleston, 32.7688, -79.9734, 30/X/2016, Ott Lab, Q. virginiana ’.

Sexual generation – 1F Lectotype (photo only) ‘Brief mai 78 N. Amer., Collect G. Mayr, Bel. Treatae det. G. Mayr, LECTOTYPE Belonocnema treatae Mayr desig. G. Melika 998’ NHMW. 5F 6M ‘ USA: AL, Gulf Shores, 30.2558, -87.7205, 31/X/2016, Ott Lab, Q. virginiana ’; 5F 5M ‘ USA: FL, Kissimmee River, 27.3780, -81.0968, III/2016, Ott Lab, Q.virginiana ’; 10M ‘ USA: FL, Okeechobee, 27.2434, -80.8276, III/2017, Ott Lab, Q. virginiana ’; 5F 5M ‘ USA: FL, Perry, 30.1161, -83.5895, III/2016, Ott Lab, Q. virginiana ’.

Diagnosis: Belonocnema treatae can be distinguished from B. fossoria by the spur on the anterior side of fore tibia shorter than basitarsus and tibial spurs in both generations. It can also be separated from B. kinseyi in the sexual generation by the weakly delimited scutellar foveae separated broadly by a ridge and the yellowish brown colour along with a distinctive areolet in the asexual generation.

Description

Asexual female (Fig. 2E): Body length 2.8–3.2 mm (N = 35). Yellowish brown; tip of mandibles, scutellum, propodeum, mesopleural triangle, metapleuron, scutellum, hind tibia dark brown (Fig. 2E). Head finely coriaceous with sparse white setae; slightly rounded in dorsal view; 2× as broad as long in dorsal view; 1.3× as broad as long in frontal view; slightly broader than mesosoma. Gena alutaceous; not broadened behind eye in dorsal view; 1.1× broader than the cross diameter of eye. Malar space alutaceous, without striae radiating from clypeus; eye 2.2× higher than length of malar space. Inner margins of eyes parallel. OOL 1.2× longer than POL; OOL 2.4× longer than LOL; ocelli ovate, all equal in size. Transfacial distance 1.7× longer than height of eye and 1.8× longer than height of lower face; diameter of antennal torulus 1.3× longer than distance between them, distance between torulus and eye margin 3.3× longer than diameter of torulus. Lower face finely coriaceous, with white setae, without striae radiating from clypeus, median area not elevated. Clypeus trapezoid, flat, broader than high, with deep anterior tentorial pits, distinct epistomal sulcus and clypeo-pleurostomal line. Frons finely coriaceous, glabrous; vertex, interocellar area, occiput is finely coriaceous. Postgena coriaceous, glabrous. Antenna 13 segmented, longer than head + mesosoma; F1 shorter than the length of scape + pedicel, 1.6× longer than F2 (Fig. 2E). Mesosoma longer than high in lateral view. Propleuron evenly setose. Mesoscutum smooth, glabrous between notauli, alutaceous lateral to notaulus; longer than broad; notauli complete, deeply impressed for full length; median mesoscutal line distinct; anterior parallel lines and parapsidal lines absent; mesoscutellum only slightly longer than broad, slightly narrower posteriorly; shorter than mesoscutum, uniformly rugose, overhanging metanotum; scutellar foveae present. Mesopleural triangle covered with dense white setae, mesopleuron smooth, glabrous, with a few white setae along ventral and anterior margins. Lateral propodeal carinae distinctly raised and bent outwards, central propodeal area rugose; lateral propodeal area alutaceous, with dense white setae; nucha short, coriaceous. Tibia setose on anterior edge. Fore tibia prolonged on the anterior side into a curved spine, much shorter than tibial spur and basitarsus; tarsal claws simple with a slight ridge but never a full tooth. Middle and hind tibia with two spurs. Fore wing hyaline, longer than body, margin with dense cilia. Radial cell 2.5× as long as wide; 2r infumated, Rs curved upwards and thickened at apex; radial cell open; areolet large and distinct; Rs + M reaching to M; cu-a absent; cu1 broken (Fig. 2E). Metasoma shorter than head + mesosoma, 1.1× longer than high in lateral view, smooth and glabrous. Second metasomal tergite setose medially; all subsequent tergites without setae, smooth, glossy. Ventral spine of the hypopygium short, prominent part 1.2× as long as broad in ventral view, with white setae extending beyond the apex of spine (Fig. 2E).

Sexual female (Fig. 2A–C, F): Body length 3.5–4.0 mm (N = 15). Yellowish brown; flagellomeres, tip of mandibles, metascutellum, propodeum, wing veins, middle and hind tibia, and tarsi dark brown (Fig. 2A). Head finely coriaceous with sparse white setae; slightly rounded in dorsal view; 1.8× as broad as long in dorsal view; 1.2× as broad as long in frontal view; slightly broader than mesosoma. Gena alutaceous, not broadened behind eye in dorsal view; 1.3× broader than cross diameter of eye. Malar space alutaceous, without striae radiating from clypeus; eye 3× higher than length of malar space. Inner margins of eyes parallel. OOL 1.3× longer than POL; OOL 3.5× longer than LOL; ocelli ovate, all equal in size. Transfacial distance 1.4× longer than height of eye and 1.4× longer than height of lower face (Fig. 2A); diameter of antennal torulus 2× longer than distance between them, distance between torulus and eye margin equal to diameter of torulus. Lower face finely coriaceous, with white setae, without striae radiating from clypeus, median area not elevated. Clypeus trapezoid, flat, broader than high, with deep anterior tentorial pits, distinct epistomal sulcus and clypeo-pleurostomal line. Frons finely coriaceous, glabrous; vertex, interocellar area, occiput is finely coriaceous. Postgena coriaceous, glabrous. Antenna 14 segmented, longer than head + mesosoma; F1 shorter than the length of scape + pedicel, 1.4× longer than F2 (Fig. 2C). Mesosoma longer than high in lateral view. Propleuron alutaceous, with few setae. Mesoscutum smooth, glabrous between notauli, alutaceous lateral to notaulus; longer than broad; notauli complete, deeply impressed for full length (Fig. 2B); median mesoscutal line distinct; anterior parallel lines and parapsidal lines absent. Mesoscutellum only slightly longer than broad, slightly narrower posteriorly; shorter than mesoscutum, uniformly rugose, overhanging metanotum (Fig. 2B); scutellar foveae shallow, weakly delimited posteriorly, separated widely by a ridge (Fig. 2F). Mesopleuron smooth, glabrous, with a few white setae along ventral and anterior margins. Lateral propodeal carinae distinct, curved; central propodeal area rugose; lateral propodeal area alutaceous, with dense white setae; nucha short, coriaceous. Tibia setose on anterior edge. Fore tibia prolonged on the anterior side into a curved spine, much shorter than tibial spur and basitarsus (Fig. 2C); tarsal claws simple with a slight ridge but never a full tooth. Middle and hind tibia with two spurs. Fore wing hyaline, longer than body, margin with dense cilia. Radial cell 2.3× as long as wide; 2r infumated, Rs curved upwards and thickened at apex; radial cell open; areolet small and indistinct; Rs + M reaching to M; cu-a absent; cu1 broken (Fig. 2A). Metasoma shorter than head + mesosoma, 1.2× longer than high in lateral view, smooth and glabrous; second metasomal tergite setose medially; all subsequent tergites without setae, smooth, glossy. Ventral spine of the hypopygium short, prominent part 1.3× as long as broad in ventral view, with white setae extending beyond the apex of spine (Fig. 2A).

Male: 3.7 mm (N = 26). Colour and sculptures like the sexual female, antenna 15 segmented; F1 is curved, excavated and incised medially. Metasoma smaller than head + mesosoma.

Gall: Smooth, pea-like galls (4.92–5.50 mm) on the ventral side of leaves for the asexual generation, irregular shaped, multilocular galls often in clusters on the small rootlets for the sexual generation (Egan et al., 2013). The leaf galls produced by B. treatae on Q. virginiana are indistinguishable from the leaf gall produced by B. kinseyi on both Q. fusiformis (Fig. 1E) and Q. virginiana.

Host plant: Quercus virginiana and rarely on Q. geminata.

Distribution: Alabama, Florida, Georgia, Mississippi, North Carolina, South Carolina.

Biology: The asexual generation has long, straight wings and is capable of flight (Table 2). Sexualgeneration adults emerge from mid-March to end of April, corresponding with the timing of leaf flush of their main host Q. virginiana (Hood et al., 2019).

Remarks: Few specimens of this species have been collected from Q. geminata, which is unsurprising given the much later leaf flushing time of Q. geminata (Hood et al., 2019). While the lectotype of B. treatae designated from Gustav Mayr’s collection at NHMW by Melika & Bechtold (2001) was not examined physically, the high-quality image of the habitus clearly shows the diagnostic characters of B. treatae (small fore tibial spine shorter than tibial spur, broadly separated scutellar foveae).