Atrusca tigrina ( 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 : 177-180

Atrusca tigrina ( Kinsey, 1936)

Figs 586–599

Cynips ( aggregata ) tigrina Kinsey, 1936: 167 , female, gall.

Atrusca tigrina (Kinsey) : Weld 1952: 316

Types examined. HOLOTYPE female Cynips ( aggregata ) tigrina “Taxco 8NE Gro 8000’, Mex. Gall 1.7.32, 6 fms. 4.1.32”, “ Q. nudinervis, Kinsey coll.”, red “ Cynips tigrina , Holo- Paratype ”, deposited in AMNH, NYC, examined by GM. Three PARATYPE females “Taxco, 8NE, Gro 8000’, Mex., gall 1.7.32., 6 females 4.1.32”, “ Q. nudinervis Kinsey coll.”, red label “ Cynips tigrina Paratype ”, deposited in the general collection in AMNH, NYC, examined by GM.

Diagnosis. Atrusca tigrina belongs to the species group characterized by a reddish to reddish-brown body color, without dark areas on the mesoscutum, sometimes with reddish areas a few shades darker than the rest of mesoscutum but never black, 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, the mesopleuron and speculum completely smooth and lacking piliferous points, as in A. conexa , A. lucaris , and A. catena . Atrusca tigrine can be distinguished from A. conexa , A. lucaris , and A. catena by the last antennal flagellomeres 2.0× longer than wide and a long ventral spine of the hypopygium (10.0× longer than broad), while in A. conexa , A. lucaris , and A. catena the last antennal flagellomeres are shorter, subquadrate or slightly longer than broad, and the ventral spine of the hypopygium is shorter 2.8–4.0× longer than broad.

Re-description. Asexual female ( Figs 586–598 ). Body reddish brown, antenna, legs reddish brown, mesoscutum without black stripes, metasoma reddish brown.

Head rounded in frontal view, alutaceous, with sparse white setae, denser on lower face, 1.3× as broad as high and narrower than mesosoma in frontal view, 2.2× 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 delicately coriaceous, without striae radiating from clypeus; malar sulcus absent; eye 2.8× as high as height of malar space. Inner margins of eyes slightly diverging ventrally. POL 2.1× as long as OOL; OOL 1.1× as long as diameter of lateral ocellus and equal to LOL; all ocelli ovate, of same size. Transfacial distance 1.1× as long as height of eye and 1.4× as long as height of lower face; diameter of antennal torulus 1.6× as long as distance between them, distance between torulus and eye shorter than diameter of torulus; lower face delicately alutaceous along eye, delicately coriaceous below toruli, shining, with dense setae, without striae; slightly elevated median area smooth, shining, with setae. Interocellar area slightly elevated above head in frontal view, lateral ocelli prominent. Clypeus impressed, uniformly delicately coriaceous, trapezoid, nearly as broad as high, with few long setae; ventrally rounded, emarginate, with median incision; anterior tentorial pit large, rounded, epistomal sulcus and clypeo-pleurostomal line broad, well impressed. Frons and interocellar area alutaceous-reticulate, without striae, with few short setae; interocellar area elevated above head in frontal view. Vertex, occiput delicately alutaceous, postocciput, postgena smooth, shining, with sparse white setae; posterior tentorial pit large, ovate, area below impressed; occipital foramen above as high as height of postgenal bridge; hypostomal carina emarginate, continuing into postgenal sulci which run parallel in ventral half and bent outwards dorsally, postgenal bridge anteriorly slightly broader than width of occipital foramen. Antenna as long as body, with 12 flagellomeres, pedicel 1.4× as long as broad, F1 1.3× as long as scape+pedicel and 1.1× as long as F2; F2 1.1× as long as F3; F3 slightly longer than F4, all subsequent flagellomeres progressively shorter but last flagelloneres around 2.0× as long as broad, F12 equal F11; placodeal sensilla on F3–F12.

Mesosoma 1.3× as long as high, with sparse short white setae. Pronotum delicately rugose, with short rugae posteriorly; propleuron alutaceous, shining, with dense setae. Mesoscutum delicately alutaceous, with scattered piliferous points, smooth shining along parapsidal line, with sparse white setae, denser anteriorly; coriaceous between notauli in posterior 2/3 delicately; 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 lines distinct, impressed in anterior 1/3 of mesosoma length, smooth, shining; parapsidal lines indistinct, hardly traceable, indicated by smooth, shinig stripe; median mesoscutal line absent; parascutal carina narrow, smooth, reaching notaulus. Mesoscutellum uniformly dull rugose, elongated, slightly longer than broad, posteriorly rounded, with shallow invagination posterocentrally; overhanging metanotum; mesoscutellar foveae broader than high, with smooth, shining bottom, separated by broad elevated, rugose median area, which is nearly 1/3 as broad as the width of mesocutellar fovea. Circumscutellar carina complete but obscured by sculpture. Mesopleuron and speculum entirely smooth, shining without piliferous points, with a few setae ventrally; mesopleural triangle smooth, shining, with few setae; dorsal and lateral axillar areas smooth, shining, with dense setae; subaxillular bar smooth, shining, most posterior part higher than height of metanotal trough; metapleural sulcus reaching mesopleuron in upper 1/3 of its height, do not split into few delicate sulci, upper part of sulcus distinct. Metascutellum delicately coriaceous, above as high as height of smooth, shining ventral impressed area; metanotal trough smooth, shining, without setae; central propodeal area smooth, shining, with strong short irregular rugae; lateral propodeal carinae subparallel; lateral propodeal area smooth, glabrous, with long dense white setae. Nucha with irregular rugae laterally and dorsally. Tarsal claws toothed, with basal lobe.

Fore wing longer than body, normal size, with few darker spots and stripes, veins dark brown, radial cell open, 2.4× as long as broad; second abscissa of Rs 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 as long as head+mesosoma, 1.4× as high as long in lateral view; second metasomal tergum extending 3/4 of metasoma length 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 10.0× as long as broad in ventral view, with a few long setae ventrally which extend beyond apex of spine.

Body length 2.5–4.5 mm ( Kinsey 1936).

Gall ( Fig. 599 ). The gall is up to 28 mm, in average 20 mm in diameter, globular, with a truncate pedicel, light yellow to pinkish or rosy tan, conspicuously spotted and irregularly striped with rich purple, usually dusted with a blusih puberulence; singly, rarely 2– 3 in one cluster, attached to the main vein of the leaf.

Biology. The asexual generation is only known to induce leaf galls on Q. magnoliifolia (= Q. nudinervis ). Galls mature in late autumn – beginning of winter; adults emerge in March–April next year.

Distribution. Mexico: Guerrero.

Figures

FIGURES 586–591. Atrusca tigrina (Kinsey, 1936), asexual female. 586–589, head: 586, frontal view, 587, dorsal view, 588, lateral view, 589, posterior view. 590, antenna. 591, mesosoma and propleura, frontal view.

FIGURES 592–595. Atrusca tigrina (Kinsey, 1936), asexual female. 592, mesosoma, lateral view. 593, mesoscutum, dorsal view. 594, mesoscutellum, dorsal view. 595, metascutellum and propodeum, posterodorsal view.

FIGURES 596–599. Atrusca tigrina (Kinsey, 1936). 596–598, asexual female: 596, fore wing, 597–598, metasoma: 597, lateral view, 598, ventral view. 599, galls.