Atrusca strians ( Kinsey, 1930 )

Atrusca strians ( Kinsey, 1930)

Figs 558–571 View FIGURES 558–563 View FIGURES 564–567 View FIGURES 568–571

Cynips centricola variety strians Kinsey, 1930: 304 , female, gall.

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

Atrusca strians (Kinsey) : Weld 1951: 638.

Types examined. HOLOTYPE female Cynips strians var. centricola “Bonnie, Ill. Gall 10.15.27”, “ Q. alba, Kinsey View in CoL coll.”, red “ Cynips strians , Holo- Paratype ”, deposited in AMNH, NYC, examined by GM. Seven PARATYPE females “Morelia, 14E, Mich 7000’, Mex., galls 12.27.31, 234 females 3.22.32.”, “ Q. conglomerata Kinsey View in CoL coll.”, red label “ Cynips spinifera Paratype ”, deposited in the general collection in AMNH, NYC, examined by GM .

Diagnosis. Atrusca strians is characterized by 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 presents complete venation and Rs almost straight in the radial cell. The mesopleuron is setose, displaying transverse parallel striae. The median line of mesoscutum is present, while the mesoscutellum shows distinct sculpturing. The ventral spine of the hypopygium is short, approximately 2.5–3.0× as long as broad. These character states are shared by the species A. quercuscentricola . 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 558–570 View FIGURES 558–563 View FIGURES 564–567 View FIGURES 568–571 ). Body dark brown, antenna, legs dark brown, metasoma dark brown, mesoscutum dark brown with black stripes along anterior parallel and parapsidal lines, central propodeal area and lateral propodeal area reddish brown, metasoma dark brown.

Head transversally quadrangular 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, 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 delicately coriaceous, 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 2.0× as long as OOL; OOL slightly longer than lateral ocellus and 1.2× as long as LOL; all ocelli ovate, of same size. Transfacial distance 1.2× as long as height of eye and 1.7× as long as height of lower face; diameter of antennal torulus slightly shorter than distance between them, distance between torulus and eye slightly longer than 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 coriaceous to rugose, rectangular, broader than high, with few 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 rugose, without striae, with short setae. Small rounded impressed area below central ocellus smooth, shining. Vertex, occiput, postgena alutaceous-reticulate, with sparse white setae, postocciput smooth, shining; 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 parallel ventrally, bent outwards towards occipital foramen, postgenal bridge dorsally broader than width of occipital foramen. Antenna slightly longer than head+mesosoma, with 12 flagellomeres, pedicel 1.3× as long as broad, flagellomeres slightly broadened till apex, F1 1.1× as long as scape+pedicel and 1.2× as long as F2; F2 1.2× as long as F3; F3=F4, F5=F6, F7 slightly longer than F8, F9=F10=F11, F12 2.0× as long as F11; placodeal sensilla invisible.

Mesosoma 1.3× as long as high, with dense white setae. Pronotum rugose, with irregular rugae laterally; propleuron alutaceous aside, smooth, shining centrally. Mesoscutum alutaceous-reticulate aside notauli and between notauli in posterior half, rugose between notauli in anterior 1/3, with dense 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 indicated by smooth, shining stripe, extending to 1/3 of mesoscutum length; parapsidal lines indicated by broad, smoot, shining stripe; median mesoscutal line long, impressed, extending to 1/4 of mesoscutum length; parascutal carina narrow, smooth, reaching notaulus. Mesoscutellum uniformly rugose, ovate, slightly longer than broad, posteriorly rounded, with shall invagination posterocentrally; overhanging metanotum; mesoscutellar foveae transverse, broader than high, with smooth, shining bottom and some irregular rugae, separated by a narrow central carina. Circumscutellar carina complete but weakly marked distally. Mesopleuron setose with piliferus points, centroventrally with transverse parallel delicate striae, dorsal part alutaceous-reticulate; speculum alutaceous-reticulate with piliferous points; mesopleural shining, with irregular striae and few setae; dorsal and lateral axillar areas rugose, shining, with dense setae; subaxillular bar smooth, shining, most posterior part higher than height of metanotal trough; metapleural sulcus indistinct, reaching mesopleuron at mid height, upper part of sulcus indistinct. Metascutellum coriaceous, as high as height of smooth, glabrous ventral impressed area; metanotal trough shining, rugose, without setae; central propodeal area smooth, shining, with delicate rugae along lateral propodeal carinae; lateral propodeal carinae strongly bent outwards in posterior half; lateral propodeal area smooth, shining, with piliferous points and long dense white setae. Nucha with irregular rugae laterally, dorsocentrally smooth, shining. 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, 2.2× as long as broad; second abscissa of Rs gradually curved not angulated 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 slightly longer than 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 2.5× as long as broad in ventral view, with a few short setae ventrally extending beyond apex of spine.

Body length 3.0– 4.5 mm ( Kinsey 1936).

Gall ( Fig. 571 View FIGURES 568–571 ). The gall is similar to all galls of Kinsey’s bella and dugesi complexes. Mature galls globular always well spotted, brownish purple.

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

Distribution. USA: Illinois.