Atrusca pomifera ( 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 : 130-134

Atrusca pomifera ( Kinsey, 1936)

Figs 424–437

Cynips ( dugesi ) pomifera Kinsey, 1936: 176

Atrusca pomifera (Kinsey) : Weld 1952: 315.

Types examined. HOLOTYPE female Cynips ( bella ) pomifera “Sta Isabel 16E Chi 6000’, Mex. Gall 10.24.31, 150 fms. 2.1.32”, “ Q. undata, Kinsey coll.”, red “ Cynips pomifera , Holo- Paratype ”, deposited in AMNH, NYC, examined by GM. Eight PARATYPE females “Sta. Isabel, 6E, Chi 6000’, Mex., galls 10.24.31, 150 females to 2.10.32.”, “ Q. undata Kinsey coll.”, red label “ Cynips pomifera Paratype.”, deposited in the general collection in AMNH, NYC, examined by GM.

Diagnosis. Atrusca pomifera 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 coriaceous pronotum, without any stria or rugae, the entirely rugose mesoscutellum usually with a posterocentral invagination, the mesopleuron sculptured to some degree, with or without piliferous points, the completely alutaceous speculum, and a ventral spine of the hypopygium setose and relatively short, 2.5–4.5× as long as wide, as in A. emergens . Atrusca pomifera differs from A. emergens by having a transversally ovate head, the smooth mesoscutellar foveae, the lateral propodeal areas lacking piliferous points, the central propodeal area exhibiting delicate irregular rugae, and the a presence of a dark spot on the radial cell of fore wings, while in A. emergens the head is triangular, the mesoscutellar foveae have rugose bottom, the lateral propodeal area has piliferous points, the central propodeal area is smooth, and the radial cell is hyaline.

Re-description. Asexual female ( Figs 424–436 ). Head predominantly dark brown, central part of lower face and head posteriorly black; antenna uniformly dark brown; mesoscutum and mesoscutellum dark brown, with black stripes along anterior parallel and parapsidal lines; mesoscutellar foveae black; mesopleuron laterally with darker parts, legs dark brown; metasoma dark brown, second metasomal tergum lighter.

Head transversally ovate in frontal view, alutaceous, with sparse white setae, denser on lower face and along inner margins of eye, 1.3× as broad as high and narrower than mesosoma in frontal view, 2.2× as broad as long in dorsal view. Gena alutaceous, not broadened behind eye in frontal view, 2.0× as narrow as cross diameter of eye in lateral view. Malar space coriaceous-reticulate, without striae radiating from clypeus; malar sulcus absent; 2.1× as high as height of malar space. Inner margins of eyes parallel. POL 1.7× as long as OOL; OOL 1.9× as long as diameter of lateral ocellus and 1.4× as long as LOL; all ocelli ovate, of same size. Transfacial distance 1.4× as long as height of eye; diameter of antennal torulus as long as distance between them, distance between torulus and eye slightly longer than diameter of torulus; lower face alutaceous, along sides, delicately rugose below toruli, with white setae, without striae; slightly elevated median area delicately rugose, with setae. Interocellar area slightly elevated above head in frontal view, lateral ocelli prominent. Clypeus impressed, uniformly delicately coriaceous, trapezoidal more than 2.0× as broad as high, with 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 delicately coriaceous, without striae, with few short setae. Vertex, occiput delicately coriaceous, with dense setae; postocciput, postgena smooth, shining, postgena with dense setae; posterior tentorial pit large, ovate, area below impressed; occipital foramen slightly higher than height of postgenal bridge; hypostomal carina emarginate, continuing into strong, broad postgenal sulci which bent outwards towards occipital foramen, postgenal bridge dorsally broader than width of occipital foramen. Postoccipital carina strong. Antenna slightly shorter than length of body, with 12 flagellomeres, pedicel slightly longer than broad, flagellomeres slightly broadened till apex, F1 slightly longer than scape+pedicel and slightly longer than F2; F2 slightly longer than F3; F3=F4, subsequent flagellomeres till F7 progresively shorter, F8 till F12 equal in length; placodeal sensilla on F3–F12.

Mesosoma 1.3× as long as high, with dense setae. Pronotum delicately coriaceous laterally, with dense setae; propleuron alutaceous, shining, with dense setae. Mesoscutum uniformly alutaceous, with dense setae and piliferous points; 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 smooth darker stripes; median mesoscutal line absent; parascutal carina narrow, smooth, reaching notaulus. Mesoscutellum uniformly dull rugose, ovate, as long as broad, posteriorly rounded, overhanging metanotum; mesoscutellar foveae, rounded, above as broad as high, with smooth, shining bottom, separated by broad elevated rugose central area. Circumscutellar carina complete. Mesopleuron and speculum alutaceous, smooth only in central part, shining, with few setae ventrally; mesopleural triangle delicately coriaceous, with dense setae; dorsal axillar and lateral axillar areas delicately coriaceous, with setae; subaxillular bar smooth, glabrous, most posterior part higher than height of metanotal trough; metapleural sulcus reaching mesopleuron at half height, upper part of sulcus distinct. Metascutellum delicately coriaceous, as high as height of smooth, shining ventral impressed area; metanotal trough smooth, shining, with dense setae; central propodeal area smooth, shining, with some delicate irregular rugae; lateral propodeal carinae bent outwards in posterior 1/3; lateral propodeal area smooth, shining, with long dense white setae and without piliferous points. Nucha with irregular rugae laterally, smooth, shining dorsocentrally. 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, 2.0× as long as broad with a spot; second abscissa of Rs strongly curved distally; R1 and Rs nearly reaching wing margin; areolet triangular, indistinct, Rs+M inconspicuous, complete, reaching basalis in lower half of its height.

Metasoma slightly longer than head+mesosoma, higher than long in lateral view; second metasomal tergum extending 3/4 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 2.0× as long as broad in ventral view, with setae extending beyond apex of spine.

Body length 1.8–3.5 mm ( Kinsey 1936).

Galls ( Fig. 437 ). The gall is similar to all galls of Kinsey’s bella and dugesi complexes, globular. Mature galls rosy or more often light-yellow tan, always conspicuously mottled with purplish brown, up to 22 mm, in average 14 mm in diameter.

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

Distribution. Mexico: Chihuahua.

Figures

FIGURES 424–429. Atrusca pomifera (Kinsey, 1936), asexual female. 424–427, head: 424, frontal view, 425, dorsal view, 426, lateral view, 427, posterior view. 428, antenna. 429, mesosoma and propleura, frontal view.

FIGURES 430–433. Atrusca pomifera (Kinsey, 1936), asexual female. 430, mesosoma, lateral view. 431, mesoscutum, dorsal view. 432, mesoscutellum, dorsal view. 433, metascutellum and propodeum, posterodorsal view.

FIGURES 434–437. Atrusca pomifera (Kinsey, 1936). 434–436, asexual female: 434, fore wing, part. 435–436, metasoma: 435, lateral view, 436, ventral view, part. 437, galls.