Atrusca finitima ( Kinsey, 1936 )

Atrusca finitima ( Kinsey, 1936)

Figs 290–303 View FIGURES 290–295 View FIGURES 296–299 View FIGURES 300–301 View FIGURES 302–303

Cynips View in CoL ( aggregata ) finitima Kinsey, 1936: 165 , female, gall.

Atrusca finitima (Kinsey) : Weld 1952: 314.

Types examined. HOLOTYPE female Cynips View in CoL ( aggregata ) finitima “Pacheco 13 NE Chi 7400’, Mex. Gall 10.14.31, 3 fms. 2.4.32”, “ Q. sacame, Kinsey View in CoL coll.”, red “ Cynips finitima , Holo- Paratype ”, deposited in AMNH, NYC, examined by GM. Two PARATYPE females “Pacheco 20E, Chi 7400’, Mex., galls 10.14.31, 3 females 2.4.32.”, “ Q. sacame Kinsey View in CoL coll.”, red label “ Cynips finitima Paratype ”, deposited in the general collection in AMNH, NYC, examined by GM.

Diagnosis. Atrusca finitima belongs to the couplet characterized by a brown to black body color, with dark stripes in the mesoscutum, the rugose lateral sides of the pronotum, exhibiting fore wings with a complete and conspicuous venation, the Rs vein of radial cell being strongly curved distally, never almost straight, the entirely rugose mesoscutellum displaying a posterocentral invagination, the mesopleuron and the speculum are completely smooth, without piliferous points, and a setose ventral spine of the hypopygium, with setae extending beyond the apex of the spine, as in A. spiculi . Atrusca finitima can be distinguished from A. spiculi by the parallel inner margins of the eyes; F9–F10 are at least 2.0× as long as broad; the mesoscutellum with extremely strong rugae forming parallel lines, the smooth lateral propodeal areas; and the prominent part of the ventral spine of the hypopygium very long (10.8× as long as broad in ventral view), while in A. spiculi the inner margin of eyes ventrally diverge, F9–F10 are subquadrate or slightly longer than broad; the mesoscutellum is rugose without parallel sculpture; the lateral propodeal areas are coriaceous; and the ventral spine of hypopygium is shorter (7.2× as long as broad).

Re-description. Asexual female ( Figs 290–302 View FIGURES 290–295 View FIGURES 296–299 View FIGURES 300–301 View FIGURES 302–303 ). Body, antenna, legs dark brown; mesoscutum with black stripes along anterior parallel and parapsidal lines.

Head transversely quadrangular in frontal view, mainly rugose in frontal view, with sparse white setae, 1.2× as broad as high and narrower than mesosoma in frontal view, 1.9× as broad as long in dorsal view. Gena alutaceous, slightly broadened behind eye in frontal view, narrower than transverse diameter of eye in lateral view. Malar space alutaceous, with few striae radiating from clypeus and reaching eye; malar sulcus absent; eye 2.5× as high as height of malar space. Inner margins of eyes parallel. POL 1.8× as long as OOL; OOL 1.9× as long as diameter of lateral ocellus and nearly equal to LOL; all ocelli ovate, of same size. Transfacial distance 1.2× as long as height of eye and 1.4× as long as height of lower face; diameter of antennal torulus 1.7× as long as distance between them, distance between torulus and eye equal to diameter of torulus; lower face alutaceous along eyes, dull rugose centrally, under 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 alutaceous, rectangular, broader than high, with few long setae; ventrally rounded, emarginate, with weak median incision; anterior tentorial pit large, rounded, epistomal sulcus and clypeo-pleurostomal line broad, well impressed. Frons and interocellar area dull rugose, with extremely strong rugae, with few short setae. Vertex, occiput delicately 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 slightly longer than head+mesosoma, with 12 flagellomeres, pedicel 1.3× as long as broad, F1 1.4× as long as scape+pedicel and equal F2; F2 1.2× as long as F3; F3 shorter than F2 and nearly equal F4, F5 shorter than F4, F6=F7, subsequent flagellomeres shorter, F12 slightly longer than F11; placodeal sensilla visible on F5–F12.

Mesosoma 1.2× as long as high, with sparse short white setae.Pronotum with net of strong irregular rugae laterally, shining, with sparse setae; propleuron alutaceous asides, centrally smooth, shining, with few setae. Mesoscutum uniformly alutaceous, with piliferous points and sparse white setae; 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 impressed, extending to 1/3 of mesoscutum length, marked by black stripe; parapsidal lines indistinct, hardly traceable, indicated by smooth stripe surface; median mesoscutal line absent; parascutal carina narrow, smooth, reaching notaulus. Mesoscutellum uniformly dull rugose, with extremely strong rugae; ovate, slightly longer than broad, with subparallel sides, broadest part in posterior 1/3, posteriorly rounded, with distinct shallow invagination posterocentrally, overhanging metanotum; mesoscutellar foveae, transverse, broader than high, with smooth, glabrous bottom and strong irregular rugae; separated by a narrow central carina. Circumscutellar carina complete. Mesopleuron and speculum smooth, shining, with a few setae ventrally without piliferous points; mesopleural triangle smooth, shining, with some setae; dorsal and lateral axillar areas smooth, shining, with white setae; subaxillular bar smooth, shining, most posterior part higher than height of metanotal trough; metapleural sulcus reaching mesopleuron at midheight, upper part of sulcus only partially distinct. Metascutellum rugose, shining, shorter than height of smooth, glabrous ventral impressed area; metanotal trough smooth, glabrous, without setae; central propodeal area narrow, smooth, glabrous, without striae; lateral propodeal carinae subparallel, only very slightly bent outwards in posterior 1/3; lateral propodeal area smooth, shining, with long dense white setae. Nucha with irregular rugae laterally and dorsally. Tarsal claws toothed, with basal lobe.

Brachypterous but fore wing slightly shorter than normal size, longer than body, with darker spots and stripes, veins dark brown, radial cell open, 2.0× as long as broad; second abscissa of Rs strongly curved distally; R1 and Rs nearly reaching wing margin; areolet triangular, indistinct; areolet triangular, indistinct, Rs+M inconspicuous, traceable along entire length, reaching basalis slightly below half of its height.

Metasoma as long as head+mesosoma, higher than long in lateral view; second metasomal tergum extending 1/2 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 10.8× as long as broad in ventral view, with setae extending beyond apex of spine.

Body length 3.2–4.2 mm ( Kinsey 1936).

Gall ( Fig. 303 View FIGURES 302–303 ). The gall up to 25 mm, in average 19 mm in diameter, with a slender, sharply-pointed pedicel at the base; light yellow tan to dark russet brown, usually spotted or irregularly striped, with dull purple, often with a whitish or bluish puberulence; singly or more often in large clusters; galls inserted in cracks in the bark of young twigs.

Biology. The asexual generation is only known to induce leaf galls on Q. arizonica (= Q. sacame ). Galls mature in late autumn; adults emerge from February next year.

Distribution. Mexico: Chihuahua.