Belonocnema mesoamericana Zhang, Zaldívar-Riverón & Fernández-Flores sp. nov.

Figs 1 D, 3 A – F, 4 A – F

Type material.

Holotype. Asexual generation. Mexico • Veracruz, Municipio Actopan, Otates; 19°30'42.44"N, 96°42'59.98"W; 12/IV/2024; A. Zaldívar, P. Goncalves, cols.; ex. root galls Q. oleoides.

Paratypes. Asexual generation: 27 specimens • Twelve females; México, Veracruz, Xalapa, Chavarrillo; 17/X/2025; 19°25'12.12"N, 96°46'48"W; manual; 900 m; A. Zaldívar, L. Rios, A. Rangel, D. Alemeda, J. Solis, cols.; Quercus oleoides, agalla IV, Belonocnema sp., haz de hoja, múltiples semillas, rojizas • Six females; México, Veracruz, Actopan, “ Los Otates ”; 22/XI/2019; 19°30'18.7"N, 96°43'16.7"W; manual; 840 m; A. Zaldívar, J. Solis, S. Fernández, cols.; Quercus oleoides, agalla IV, Belonocnema sp., haz de hoja, múltiples semillas, rojizas • Seven females; Los Otates, sitio # 1; 22/XI/2019; 19°30'48.2"N, 96°43'08.0"W; manual; 720 m; bosque de encino; Cyniver- 47; A. Zaldívar, S. Fernández, S. Egan, R. Castañeda, J. Solis, cols • One female; Los Otates; sitio # 1; 22/XI/2019; 19°30'48.2"N, 96°43'08.0"W; manual; 720 m; bosque de encino; Cyniver- 48; A. Zaldívar, S. Fernández, S. Egan, R. Castañeda, J. Solis, cols • One female; Los Otates; sitio # 1; 22/XI/2019; 19°30'48.2"N, 96°43'08.0"W; manual; 720 m; bosque de encino; Cyniver- 49; A. Zaldívar, S. Fernández, S. Egan, R. Castañeda, J. Solis, cols • One female; Los Otates; sitio # 1; 22/XI/2019; 19°30'48.2"N, 96°43'08.0"W; manual; 720 m; bosque de encino; Cyniver- 50; A. Zaldívar, S. Fernández, S. Egan, R. Castañeda, J. Solis, cols.

Sexual generation • four females; same data as holotype; DNA voucher numbers CNIN 5137, 38 [GenBank (COI) no. PZ 044865; SRA (UCEs) accession nos SAMN 55915580 –81] • One female, five males; Veracruz, Municipio Actopan, Los Otates; 12/VI/2025; 19°30'36.7"N, 96°42'58.3"W; manual; 800 m; A. Zaldívar, J. Sols, E. Rangel, cols.; Quercus oleoides, agalla VIII, Belonocnema sexual de raíz tumorosa, aterciopelada, amarillento oscuro.

Diagnosis.

Belonocnema mesoamericana sp. nov. is morphologically similar to its sister species, B. kinseyi, with both species having the spur on the anterior side of the fore tibia shorter than basitarsus and tibial spurs and the middle tibia without a spur in both generations (Fig. 3 E). However, B. mesoamericana can be distinguished from B. kinseyi by its lateral propodeal carinae bent outwards (Fig. 4 F) (straight in B. kinseyi), central propodeal area rugose (Fig. 4 F) (punctate in B. kinseyi), and OOL 3.5 × longer than LOL (Fig. 4 E) (2.2 × in B. kinseyi) in females of the sexual generation. The new species can also be distinguished from B. kinseyi by its lateral propodeal area rugose (alutaceous in B. kinseyi) and body color partially yellowish brown (Fig. 3 A), with some specimens almost entirely dark brown (Fig. 1 D) (always reddish brown in B. kinseyi) in most females of the asexual generation. Moreover, B. mesoamericana is the only species of the genus in which the rootlet galls formed by the sexual generation are velvety (Fig. 5 C).

Description.

Asexual female (Figs 1 D, 3 A – E): Body length 2.0–3.0 mm (N = 30). Yellowish to reddish brown, some specimens almost entirely dark brown; tip of mandibles, mesosoma (except pronotum), wing veins, anterior edge of meso, and metacoxae, distal edge of metafemur, fore, meso and meta tibia dark brown to black. Head finely coriaceous with sparse white setae; slightly rounded in dorsal view; 2.3 × as broad as long in dorsal view; 1.4 × as broad as long in frontal view; slightly broader than mesosoma. Gena finely coriaceous, not broadened behind eye in frontal view, equally broad as cross diameter of eye. Malar space finely coriaceous, without striae radiating from clypeus; eye 2.3 × higher than length of malar space, malar sulcus present. Inner margins of eyes parallel. OOL 1.4 × longer than POL; OOL 2.3 × longer than LOL; ocelli ovate, all equal in size. Transfacial distance 1.7 × longer than height of eye and 1.1 × longer than height of lower face; diameter of antennal torulus 1.9 × longer than distance between them, distance between torulus and eye margin 1.5 × 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, sparsely pubescent; vertex, interocellar area, and occiput finely coriaceous. Postgena coriaceous, glabrous. Antenna 13 segmented, longer than head + mesosoma; F 1 shorter than the length of scape + pedicel, 1.6 × longer than F 2. Mesosoma 1.2 × longer than high in lateral view. Propleuron alutaceous, with short, sparse setae. Pronotum laterally striate finely rugose. Mesoscutum smooth, largely glabrous except for sparse setae on either side of notauli, alutaceous lateral to notaulus; longer than broad; notauli complete, deeply impressed for full length; median mesoscutal line absent; anterior parallel lines almost indistinct, parapsidal lines absent. Mesoscutellum as long as broad, slightly narrower posteriorly; distinctly shorter than mesoscutum, uniformly rugose, overhanging metanotum; scutellar foveae present, deep, smooth to slightly rugose, separated narrowly by carina. Mesopleural triangle with white sparse short setae, mesopleuron smooth, glabrous, with dense white setae along 2 / 3 of the way on the anterior and ventral margins. Lateral propodeal carinae distinct, bent outwards; central and lateral propodeal areas rugose, lateral propodeal area with dense white setae; nucha very 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. Fore tibia with one and mid and hind tibia with two asymmetrical spurs. Fore wing hyaline, longer than body, margin with dense cilia; radial cell about 2 × as long as wide; 2 r infumated, Rs curved upwards and thickened at apex; radial cell open; areolet open and distinct; Rs + M reaching to M; cu-a absent; Cu 1 broken. Metasoma as long as head + mesosoma, 1.2 × longer than high in lateral view, smooth; second metasomal tergite setose laterally and medially; all subsequent tergites without setae, smooth, glossy; ventral spine of the hypopygium short, prominent part 1.7 × as long as broad in ventral view, with white setae extending beyond the apex of spine.

Sexual female (Fig. 4 A – F): Body length 3.4–4.0 mm (N = 6). Yellowish brown; pedicel, flagellomeres, tip of mandibles, central and sometimes lateral propodeal area, wing veins, hind tibia and tarsi dark brown. Head finely coriaceous with sparse white setae; slightly rounded in dorsal view; 2.2 × as broad as long in dorsal view; 1.2 × as broad as long in frontal view; slightly broader than mesosoma. Gena coriaceous, not broadened behind eye in dorsal view; 0.7 as broad as cross diameter of eye. Malar space coriaceous, without striae radiating from clypeus; eye 1.9 × higher than length of malar space, malar sulcus present. Inner margins of eyes parallel. OOL 1.2 × longer than POL; OOL 3.5 × longer than LOL; ocelli ovate, all equal in size. Transfacial distance 1.5 × longer than height of eye and 1.4 × longer than height of lower face; diameter of antennal torulus about 2 × longer than distance between them, distance between torulus and eye margin 1.2 × longer than diameter of torulus. Lower face finely coriaceous-slightly rugulose, with white sparse 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, with sparse white setae; vertex, interocellar area and occiput finely coriaceous. Postgena coriaceous-finely rugose. Antenna 14 segmented, longer than head + mesosoma; F 1 shorter than the length of scape + pedicel, 1.5 × longer than F 2. Mesosoma 1.3 × longer than high in lateral view. Propleuron alutaceous, with sparse setae. Pronotum mostly smooth with fine striae. Mesoscutum mostly smooth, glabrous between notauli and sparse white setae along them, alutaceous lateral to notaulus; 1.1 × longer than broad; notauli complete, deeply impressed for full length; median mesoscutal line almost indistinct, only weakly impressed in the posterior margin of mesoscutum; 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 deeply excavated, smooth to slightly rugose, fully delimited on all sides, separated narrowly by carina. Mesopleuron smooth, glabrous, with a few white setae along ventral and anterior margins; mesopleural triangle setose. Lateral propodeal carinae distinct, bent outwards, central propodeal area glabrous, rugose; lateral propodeal area alutaceous, with long white setae; nucha short, smooth. Tibiae setose, with long setae on anterior edge. Fore tibia with a single and middle and hind tibia with two spurs. Fore tibia prolonged on the anterior side into a curved spine, considerably shorter than tibial spur and basitarsus; spur of fore tibia one third the size of basitarsus. Middle tibia with a small, curved spine, shorter than tibial spurs. Tarsi setose. tarsal claws simple, with a slight basal ridge but never a full tooth. Fore wing hyaline, longer than body, margin with dense cilia; radial cell about 2.5 × longer than wide; 2 r infumated, Rs curved upwards and thickened at apex; radial cell open; areolet small and distinct; Rs + M reaching to M; cu-a absent; cu 1 broken. Metasoma shorter than head + mesosoma, 1.2 × longer than high in lateral view, smooth and glabrous; first and second metasomal tergites with sparse, short setae laterally; all subsequent tergites without setae, smooth, glossy. Ventral spine of the hypopygium short, prominent part 2.5 × longer than broad in ventral view, with white setae extending beyond the apex of spine.

Male (Fig. 3 F): Body length 2.6–3.0 mm (N = 5). Color slightly darker than sexual female; pedicel, lateral propodeal area and venter of mesopleuron dark brown to black. Sculptures like the sexual female. Antenna 15 segmented. F 1 curved, excavated, and incised medially. Metasoma smaller than head + mesosoma.

Galls.

Galls of the asexual generation are unilocular, pea-like, and occur on the ventral side of leaves (Fig. 5 A). The number of galls varies from one to several, and they are irregularly arranged across the leaf. Gall color varies from pale green to reddish, becoming dark to greyish brown after insect emergence. Galls of the sexual generation, on the other hand, are globose, irregularly shaped, forming multilocular clusters on small rootlets. They have a velvety texture and are brown to light brown, turning paler and losing the velvety appearance after insect emergence (Fig. 5 B, C). Rootlet galls formed by the sexual generation in the known species of Belonocnema can exhibit a lightly pubescent surface made of fine, short hairs in early growth that decreases as they mature. However, B. mesoamericana rootlet galls are densely pubescent throughout growth and maturation and the surface of the gall could be described as velvet-like.

A total of 332 and 22 specimens of B. mesoamericana were reared from galls formed by its asexual and sexual generations, respectively. Leaf galls of the asexual generation of B. mesoamericana were considerably abundant in the localities where they occurred. They were recorded from September to November, with most gallers and its associated hymenopterans emerging during late October to early November. Rootlet galls, on the other hand, appear to be scarcer and are considerably more difficult to find. We searched for this type of gall only in the locality of Los Otates during April in two consecutive years (2024–2025), finding them exclusively around a single tall tree near the soil surface. Further collections in other localities will allow to know the abundance of sexual galls in B. mesoamericana.

Plant host.

The host plant of B. mesoamericana, Q. oleoides, is the most widespread oak species of the section Virentes, occurring from northern Mexico in Tamaulipas, to Costa Rica in Central America (Valencia 2004; Cavender-Bares et al. 2011, 2015). It has been reported in dry and tropical sub-deciduous forests at elevations that range from 150 to about 1000 m (Valencia, 2004).

Distribution.

Belonocnema mesoamericana is currently only known from central Veracruz, Mexico. However, based on the geographic distribution of its oak host, its distribution is presumably broader.

Etymology.

The name of the new species refers to the cultural-historical region situated in the Neotropics that extends from central Mexico to northwest Costa Rica, which mostly covers the geographic distribution of its host plant species, Q. oleoides.