Atrusca subnigra ( Kinsey, 1936 )

Cuesta-Porta, Victor, Melika, George, Ferrer-Suay, Mar, Vera-Ortiz, Alexis & Pujade-Villar, Juli, 2025, Review of the Nearctic and Neotropical genus Atrusca Kinsey, 1930 (Hymenoptera: Cynipidae, Cynipini), Zootaxa 5617 (1), pp. 1-195 : 173-177

Atrusca subnigra ( Kinsey, 1936)

Figs 572–585

Cynips ( dugesi ) subnigra Kinsey 1936: 140 , female, gall.

Atrusca subnigra (Kinsey) : Weld 1951: 638.

Types examined. HOLOTYPE female Cynips subnigra ( dugesi ) “Las Cruces 16E N.M. Gall 10.6.31 107 fms. 1.26.32”, “ Q. grisea, Kinsey coll.”, red “ Cynips subnigra , Holo- Paratype ”, deposited in AMNH, NYC, examined by GM. Two PARATYPE females “Las Cruces 16E, N.M.”, “ Q. grisea Kinsey coll.”, red label “ Cynips subnigra Paratype ”, deposited in the general collection in AMNH, NYC, examined by GM.

Diagnosis. Atrusca subnigra belongs to the couplet characterized by a dark brown to black body color, with conspicuous black stripes on the mesoscutum, with a complete fore wing venation, the Rs vein of radial cell being strongly curved distally, never almost straight, the rugose or transversally striate pronotum, the entirely rugose mesoscutellum, the mesopleuron sculptured to some degree, with or without piliferous points, the completely smooth speculum, and a ventral spine of the hypopygium setose and relatively short, 2.5–4.5× as long as wide, as in A. deceptrix and A. simulatrix . Atrusca subnigra differs from A. deceptrix and A. simulatrix by having no piliferous points in the mesoscutum especially between the notauli in the posterior half, the slightly posteriorly pointed mesoscutellum, the irregularly rugose mesoscutellar foveae, and the strongly angulate distal part of the Rs vein, while in A. deceptrix and A. simulatrix the mesoscutum is uniformly covered in piliferous points, the mesoscutellum is rounded or with a shallow central invagination on the posterior margin, the mesoscutellar foveae are smooth, and the Rs vein is moderately angulate.

Re-description. Asexual female ( Figs 572–584 ). Head, antenna, mesosoma, legs uniformly dark reddish brown, palpi brown; mesoscutum dark brown, with black stripe along anterior parallel lines, extending to 2/3 of mesoscutum length; parapsidal line with broad black stripe, metascutellum, metanotal trough black; metasoma lighter with a posterior dark stripe on second metasomal tergum.

Head transversely ovate in frontal view, alutaceous, with sparse white setae, 1.3× as broad as high and narrower than mesosoma in frontal view, 1.8× as broad as long in dorsal view. Gena alutaceous, broadened behind eye in frontal view, narrower than transverse diameter of eye in lateral view. Malar space coriaceous-reticulate, without striae radiating from clypeus; malar sulcus absent; eye 2.3× as high as height of malar space. Inner margins of eyes diverging ventrally. POL 1.4× as long as OOL; OOL 1.7× as long as diameter of lateral ocellus and 1.7× as long as LOL; all ocelli ovate, of same size. Transfacial distance 1.3× as long as height of eye and 1.6× as long as height of lower face; diameter of antennal torulus 1.3× as long as distance between them, distance between torulus and eye 1.4× equal to diameter of torulus; lower face alutaceous asides, rugose in central part below toruli, with few setae; slightly elevated median area rugose, shining, without setae. Interocellar area elevated above head in frontal view, lateral ocelli prominent. Clypeus impressed, uniformly delicately coriaceous, rectangular, broader than high, with few long setae; ventrally rounded, emarginate, without median incision; anterior tentorial pit large, rounded, epistomal sulcus and clypeo-pleurostomal line broad, well impressed. Frons and interocellar area dull rugose, with few short setae. Vertex, occiput coriaceous; postocciput, postgena smooth, shining with sparse white setae; posterior tentorial pit large, ovate, area below impressed; occipital foramen slightly higher than height of postgenal bridge; hypostomal carina emarginate, continuing into postgenal sulci which run towards occipital foramen, dorsally bent outwards, postgenal bridge smooth, shining, anteriorly broader than posteriorly and slightly broader than width of occipital foramen. Antenna longer than head+mesosoma, with 12 flagellomeres, all in long dense setae, pedicel 1.6× as long as broad, F1 1.1× as long as scape+pedicel and 1.2× as long as F2; F2 1.2× as long as F3; F3 slightly longer than F4, subsequent flagellomeres progressively shorter, F12 equal F11; placodeal sensilla invisible.

Mesosoma 1.3× as long as high, with sparse short white setae. Pronotum alutaceous in dorsoventral part and with some delicate rugae along posterior edge, smooth, shining in anterior part, with sparse setae; propleuron alutaceous aside, smooth, shining centrally, with dense setae. Mesoscutum predominantly alutaceous-reticulate, delicately rugose in anterior 1/3 of mesoscutum length, with indistinct piliferous points, with setae, denser anteriorly and along notauli; slightly longer than broad (greatest width measured across mesoscutum at level of base of tegulae). Notaulus complete, deep, broad, with smooth, glabrous bottom, posteriorly broader and slightly converging; anterior parallel and parapsidal lines indistinct, hardly traceable, indicated by smoother surface; median mesoscutal line absent; parascutal carina narrow, smooth, reaching notaulus. Mesoscutellum uniformly dull rugose, trapezoid, slightly broader in posterior 1/3, posteriorly gradually narrowing to posterocentral part, not rounded posteriorly (slightly pointed distally), overhanging metanotum; mesoscutellar foveae transverse, broader than high, smooth, shining, with some irregular rugae, separated by narrow elevated rugose central area. Circumscutellar carina complete. Mesopleuron alutaceous only in anterodorsal quarter, smooth, shining on rest surface, with few sparse setae; speculum smooth, shining; mesopleural triangle with some irregular rugae and dense setae; dorsal axillar and lateral axillar areas delicately rugose, with dense setae; subaxillular bar smooth, glabrous, most posterior part as high as height of metanotal trough; metapleural sulcus reaching mesopleuron slightly above mid height, upper part of sulcus distinct. Metascutellum delicately rugose, slightly higher than height of smooth, shining ventral impressed area; metanotal trough smooth, shining, without setae; central propodeal area smooth, shining, with irregular rugae, broadest part slightly below mid height of propodeum; lateral propodeal carinae gradually bent outwards; lateral propodeal area delicately rugose, shining, with sparse setae. Nucha with delicate parallel sulci laterally and dorsally. Tarsal claws toothed, with basal lobe.

Fore wing longer than body, normal size, margin with long dense cilia, with numerous slightly darker spots and stripes, veins dark brown, radial cell open, 1.8× as long as broad; second abscissa of Rs strongly curved distally; R1 and Rs nearly reaching wing margin; areolet triangular, distinct, Rs+M inconspicuous, hardly traceable along entire length, reaching basalis slightly below its mid height.

Metasoma slightly longer than head+mesosoma, higher than long in lateral view; second metasomal tergum extending to 2/3 of metasoma length of in dorsal view, with white setae anterolaterally, without band of micropunctures posteriorly; subsequent terga without micropunctures, without setae. Hypopygium without micropunctures, prominent part of ventral spine of hypopygium 3.8× as long as broad in ventral view, with setae extending beyond apex of spine.

Body length 2.0–4.0 mm ( Kinsey 1936).

Gall ( Fig. 585 ). The gall is similar to all galls of Kinsey’s bella and dugesi complexes; indistinguishable from other galls of the bella complex. Mature galls rosy or brownish tan, unspotted or obscurely mottled, usually shining, up to 25 mm, in average 20 mm in diameter.

Biology. The asexual generation is only known to induce leaf galls on Q. grisea . Galls mature in late autumn; adults emerge in January–February next year.

Distribution. USA: New Mexico.

Figures

FIGURES 572–577. Atrusca subnigra (Kinsey, 1936), asexual female. 572–575, head: 572, frontal view, 573, dorsal view, 574, lateral view, 575, posterior view. 576, antenna. 577, mesosoma and propleura, frontal view.

FIGURES 578–581. Atrusca subnigra (Kinsey, 1936), asexual female. 578, mesosoma, lateral view. 579, mesoscutum, dorsal view. 580, mesoscutellum, dorsal view. 581, metascutellum and propodeum, posterodorsal view.

FIGURES 582–585. Atrusca subnigra (Kinsey, 1936). 582–584, asexual female: 582, fore wing, 583–584, metasoma: 583, lateral view, 584, ventral view. 585, galls.