Atrusca clivorum ( Kinsey, 1930 )

Atrusca clivorum ( Kinsey, 1930)

Figs 173–185 View FIGURES 173–178 View FIGURES 179–182 View FIGURES 183–185

Cynips centricola variety clivorum Kinsey 1930: 300 , female, gall.

Cynips (Atrusca) ( centricola ) clivorum Kinsey 1936: 181 .

Atrusca clivorum (Kinsey) : Weld 1951: 638.

Types examined. HOLOTYPE female Cynips clivorum var. centricola “ Coolville, Ohio. Gall 10.24.28, 8 fms. 12.9.28”, red “ Cynips clivorum , Holo- Paratype ”, deposited in AMNH, NYC, examined by GM. Three PARATYPE females “ Coolville , Ohio, galls 10.14.28, 5 females 11.13.28”, “ Q. stellata Kinsey View in CoL coll.”, red label “ Cynips clivorum . Paratype ”, deposited in the general collection in AMNH, NYC, examined by GM .

Diagnosis. Atrusca clivorum is characterized by having a brown body, the transversely ovate head with the interocellar area strongly elevated above the head in frontal view, and prominent lateral ocelli. The fore wing exhibits a complete venation and Rs gradually curved in the radial cell, almost straight. The ventral spine of the hypopygium is short, 2.5–3.0× as long as broad. These character states are shared by the species A. strians and A. quercuscentricola . Atrusca clivorum can be distinguished from A. strians and A. quercuscentricola by the laterally alutaceous pronotum, the absence of a median mesoscutal line and the mesopleuron and speculum uniformly alutaceous to smooth, without piliferous points. In A. strians , the pronotum is rugose with prominent lateral rugae, the long median mesoscutal line extends for one-fourth of the mesoscutum, and the mesopleuron is setose, displaying transverse parallel striae, while A. quercuscentricola presents a uniformly alutaceous-reticulate pronotum, without setae; the median mesoscutal line superficial, and alutaceous-reticulate mesopleuron without setae.

Re-description. Asexual female ( Figs 173–184 View FIGURES 173–178 View FIGURES 179–182 View FIGURES 183–185 ). Head dark brown, posteriorly black, malar space reddish brown; antenna uniformly dark brown; palpi light brown; mesosoma laterally dark brown to black, with lighter ventral half of mesopleuron; mesoscutum predominantly dark brown to black, with ligher posterior part; propleron reddish brown; propodeum dark brown, mesoscutellum reddish brown, legs dark brown; metasoma dark brown, second metasomal tergum with black band posteriorly.

Head transversely quadrangular in frontal view, alutaceous, with sparse white setae, 1.3× as broad as high and narrower than mesosoma in frontal view, 2.0× as broad as long in dorsal view. Gena alutaceous, not or very slightly broadened behind eye in frontal view, narrower than transverse diameter of eye in lateral view. Malar space light brown, lighter than rest of lower face, alutaceous-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 1.6× as long as OOL; OOL 1.2× as long as diameter of lateral ocellus and 1.2× 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 slightly shorter than distance between them, distance between torulus and eye 1.25× as long as 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 elevated above head in frontal view, lateral ocelli prominent. Clypeus impressed, uniformly delicately coriaceous, rectangular, broader than 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 1.5× as long as broad, 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, F5=F6, F7=F8, subsequent flagellomeres shorter, nearly equal in length, F12 slightly longer than F11; placodeal sensilla on F4–F12.

Mesosoma 1.3× as long as high, with dense short white setae. Pronotum laterally alutaceous, with dense setae; propleuron uniformly alutaceous, shining, with dense setae. Mesoscutum uniformly alutaceos-reticulate, with dense 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 line impressed, extending to half length of mesoscutum length; parapsidal line indistinct, hardly traceable, indicated by bare alutaceous stripe, without setae; median mesoscutal line absent; parascutal carina narrow, smooth, reaching notaulus. Mesoscutellum uniformly delicately coriaceous, ovate, only slightly longer than broad, posteriorly rounded, with shallow invagination posterocentrally; overhanging metanotum; mesoscutellar foveae transverse, broader than high, smooth, shining, with numerous irregular rugae, separated by narrow central carina. Circumscutellar carina complete. Mesopleuron and speculum uniformly alutaceous to smooth without piliferous points, shining, with dense setae; mesopleural triangle rugose, with dense setae; dorsal and lateral axillar areas delicately coriaceous, with dense setae; subaxillular bar smooth, shining, broad, posteriorly elongated towards mesoscutellum, most posterior part higher than height of metanotal trough; metapleural sulcus reaching mesopleuron slightly below its mid height, upper part of sulcus distinct. Metascutellum delicately coriaceous, as high as height of smooth, glabrous ventral impressed area; metanotal trough delicately coriaceous, shining, with setae; central propodeal area smooth, shining, with delicate irregular rugae; lateral propodeal carinae bent outwards in posterior 1/3; lateral propodeal area coriaceous, shining, with long dense white setae. Nucha with irregular rugae laterally, smooth, shining dorsocentrally. Tarsal claws toothed, with basal lobe.

Fore wing only slightly longer than body, margin with long dense cilia, with few slightly darker spots and stripes, veins dark brown, radial cell open, 2.6× as long as broad; second abscissa of Rs gradually curved; R1 and Rs nearly reaching wing margin; areolet triangular, Rs+M inconspicuous, traceable along 3/4 of length, its projection reaching basalis in lower half of its height.

Metasoma as long as head+mesosoma, higher than long in lateral view; second metasomal tergum extending to 2/3 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 3.0× as long as broad in ventral view, with setae extending beyond apex of spine.

Body length 3.0– 4.5 mm ( Kinsey 1930).

Gall ( Fig. 185 View FIGURES 183–185 ). The gall indistinguishable from other galls of the complex. The gall is always unspotted.

Biology. The asexual generation is only known to induce leaf galls on Q. stellata . Galls mature in late autumn; adults emerge in November–December.

Distribution. USA: Ohio.