Atrusca brevipennata ( Gillette, 1893 )

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 : 31-35

Atrusca brevipennata ( Gillette, 1893)

Figs 75–88

Holcaspis brevipennata Gillette, 1893: 31 .

Disholcaspis brevipennata (Gillette) : Dalla Torre & Kieffer 1910: 373.

Andricus pellucidus Kinsey, 1920: 309 . Synonym in Weld 1922: 7.

Diplolepis brevipennata (Gillette) : Weld 1922: 7.

Cynips dugesi variety brevipennata (Gillette) : Kinsey 1930: 282, female, gall.

Cynips ( dugesi ) brevipennata (Gillette) : Kinsey 1936: 97, female, gall.

Atrusca brevipennata (Gillette) : Weld 1951: 637.

Types examined. HOLOTYPE female with red label ”Type”, pink label “Colo. 1876”, Gillette handwriting label ” Holcaspis brevipennata Gill. ”, deposited in AMNH, NYC, examined by GM. Also, one COTYPE female of Andricus pellucidus (insect damaged): “Colo. Springs, 9.28.73. Colo, W. L. Carpenter coll.”, ” Cynips brevipennata Kinsey det.”, red ” Andricus pellucidus, Cotype ”, deposited in AMNH, NYC, examined by GM.

Material examined. One female “ USA, New Mexico, Chama , ex Q. gambelli , leg. J. R. Zimmerman, 1987.09.20; adult emerge 1987.10.01.” Two females “Las Vegas 10–11.21. N.M., galls 12.31.21, adults Nov. Dec.”, “ Quercus fendleri, Weld. Coll. ”, “ Cynips brevipennata Kinsey det. 27” ; 2 females “Hopk. USA, 15635”, “Reared Nov.15.21”, “ Quercus gambelii ”, “Wetmore, Colo”, “ L.H. Weld collector”, “ Atrusca brevipennata det. J. R. Zimmerman” .

Diagnosis. Diagnosis. Atrusca brevipennata is characterized by a reddish to reddish-brown body, short fore wings (0.76–1.15× as body length) that exhibits complete venation and the Rs of the radial cell is strongly curved distally, never almost straight, the coriaceous pronotum with or without delicate rugae laterally, the uniformly colored mesoscutum or with stripes only slightly darker than the color of the mesoscutum; and the coriaceous mesoscutellum, occasionally with lateral rugae, and rounded posteriorly, as in A. dugesi . Atrusca brevipennata differs from A. dugesi by the mesoscutum that has conspicuous piliferous points, the central propodeal area displays transverse parallel delicate striae in the anterior third and irregular rugae posterolaterally, and fore wing shorter or subequal to body length (0.81–097× as body length), while in A. dugesi the mesoscutum has very few or no piliferous points, the central propodeal area is smooth and has longer fore wings (1.10–1.15× the body length).

Re-description. Asexual female ( Figs 75–87 ). Entire body, antenna, palpi, legs uniformly reddish brown.

Head triangular in frontal view, alutaceous, with sparse white setae, 1.3× as broad as high and as broad as mesosoma in frontal view, 2.0× 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, with few weak striae, malar sulcus absent; eye 2.6× as high as height of malar space. Inner margins of eyes slightly diverging ventrally. POL 1.4× as long as OOL; OOL 2.0× 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 high as height of lower face; diameter of antennal torulus 1.4× as long as distance between them, distance between torulus and eye 1.3× as long as diameter of torulus; lower face alutaceous, with dense white setae, without striae; slightly elevated median area delicately coriaceous, without setae. Interocellar area not elevated above head in frontal view, lateral ocelli prominent. Clypeus trapezoid, slightly broader than high, with very delicate transverse striae; ventrally rounded, emarginate, without median incision, with long setae; anterior tentorial pit large, rounded, epistomal sulcus and clypeo-pleurostomal line broad, well impressed. Mandibles with long setae. Frons and interocellar area alutaceous, without striae, with long setae; rounded impressed are under central ocellus smooth, shining. Vertex, occiput, postocciput, postgena uniformly delicately alutaceous, with sparse white setae; posterior tentorial pit large, ovate, area below impressed; occipital foramen slightly shorter than height of postgenal bridge; hypostomal carina emarginate, continuing into postgenal sulci which run parallel towards occipital foramen, postgenal bridge anteriorly and posteriorly of same width. Antenna slightly longer than head+mesosoma, with 12 flagellomeres, pedicel broader than long, F1 1.1× as long as scape+pedicel and 1.3× as long as F2; F2 1.2× as long as F3; F3 slightly longer than F4, F4 slightly longer than F5, F6 nearly equal F7, F8=F9, F10=F11, F12 1.7× as long as F11; placodeal sensilla on F2–F12.

Mesosoma 1.1× as long as high, with short white setae. Pronotum coriaceous, with dense setae; propleuron alutaceous along sides, smooth shining in the central part. Mesoscutum uniformly alutaceous, with sparse white setae, denser aside parapsidal line; with dense piliferous points especially between 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; parapsidal carina broad, smooth, reaching notaulus. Mesoscutellum coriaceous centrally with some irregular rugae laterally, trapezoid, slightly longer than broad, broader in posterior 1/3, posteriorly rounded,; overhanging metanotum; mesoscutellar foveae separated by elevated coriaceous central carina, transverse, broader than high, with smooth, shining bottom, orientated backwards under 45 o angle. Circumscutellar carina complete but weakly marked distally. Mesopleuron and speculum uniformly alutaceous, shining, with dense setae; mesopleural triangle smooth, shining, without striae, with long white setae; dorsal and lateral axillar areas smooth, shining, with dense white short setae; subaxillular bar smooth, shining, most posterior part slightly shorter than height of metanotal trough; metapleural sulcus reaching mesopleuron slightly below its midheight, upper part of sulcus indistinct. Metascutellum smooth, shining, 2.0× as high as height of smooth, glabrous ventral impressed area; metanotal trough smooth, shining, without setae; central propodeal area smooth, with transverse parallel delicate striae in anterior 1/3 and some irregular rugae posterolaterally; lateral propodeal carinae bent outwards at midheight; lateral propodeal area smooth, shining, with long dense white setae. Nucha with irregular rugae laterally, smooth, shining dorsocentrally. Tarsal claws toothed, with basal lobe.

Brachypterous, fore wing shorter or subequal than body, margin with long dense cilia, with few darker spots and stripes, veins dark brown, radial cell open, 1.7× as long as broad; second abscissa of Rs strongly curved distally; R1 and Rs nearly reaching wing margin; areolet triangular, indistinct, Rs+M inconspicuous, traceable along 2/3 of length, its projection reaching basalis in lower half of its height.

Metasoma longer than head+mesosoma, slightly higher than long in lateral view; second metasomal tergum extending over 4/5 of metasoma length in dorsal view, with dense white setae anterolaterally, without band of micropunctures posteriorly; subsequent terga without micropunctures. Hypopygium without micropunctures, prominent part of ventral spine of hypopygium 3.2× as long as broad in ventral view, with long setae ventrally which extend beyond apex of spine.

Body length 2.5–3.5 mm ( Kinsey 1936).

Gall ( Fig. 88 ). Similar to all galls of the Kinsey’s bella and dugesi complexes. Mature galls light rosy tan, unspotted, often shining, up to 19 mm, in average 14 mm in diameter.

Biology. The asexual generation is only known to induce leaf galls on Q. gambelii , Q. sinuata (= Q. undulata ), Q. turbinella . Mature galls in late autumn; adults start to emerge from December till January–February next year.

Distribution. USA: Colorado, New Mexico.

Figures

FIGURES 75–80. Atrusca brevipennata (Gillette, 1893), asexual female. 75–78, head: 75, frontal view, 76, dorsal view, 77, lateral view, 78, posterior view. 79, antenna. 80, mesosoma and propleura, frontal view.

FIGURES 81–84. Atrusca brevipennata (Gillette, 1893), asexual female. 81, mesosoma, lateral view. 82, mesoscutum, dorsal view. 83, mesoscutellum, dorsal view. 84, metascutellum and propodeum, posterodorsal view.

FIGURES 85–88. Atrusca brevipennata (Gillette, 1893). 85–87, asexual female: 85, fore wing, part. 86–87, metasoma: 86, lateral view, 87, ventral view, part. 88, galls.