Aulacus aneurus WALKLEY, 1952

Smith, David R., 2008, Aulacidae of the southwestern United States, Mexico, and Central America (Hymenoptera), Beiträge Zur Entomologie = Contributions to Entomology 58 (2), pp. 267-355 : 291-292

Aulacus aneurus WALKLEY

( Figs 39-41

Aulacus aneurus WALKLEY 1952: 185 .– MUESEBECK 1958: 88.– CARLSON 1979: 1114.– SMITH 2001: 269.

Diagnosis:

Entirely black. Head dull with fine transverse microsculpture. Mesonotum with fine transverse carinae. Hind coxa with cross striations. Forewing without second recurrent vein.

Female:

Length, 6.0 mm; forewing length, 4.5 mm; ovipositor length 5.5 mm. Color: Black; metasoma and legs beyond coxae more brownish. Wings clear hyaline, without black spots, veins and stigma black. Head: Antennal length 4.0X head width. Lower interocular distance 1.1X eye height; malar space 0.3X eye height ( Fig. 39 ). From above, head short and narrowing behind eyes ( Fig. 40 ). Entire head dulled with very fine, wavy microsculpture ( Figs 39, 40 ). Mesosoma: Propleuron shining, faintly reticulate to striate ventrally and anteriorly. Mesonotum with fine transverse striae, striae more diagonal on axillae and lateral parts of mesoscutellum; notauli meet transscutal articulation separately ( Fig. 41 ); pronotum shining, mostly finely striate; mesopleuron shining, finely striate dorsally, with large carinae on ventral half, mesosternum reticulate; metapleuron shining on dorsal half, reticulate on ventral half; propodeum reticulate. Hind coxa with fine transverse carinae, 2.0X longer than broad, with indistinct diagonal ovipositor guide on basal quarter of inner surface. Hind basitarsus subequal in length to remaining tarsal segments combined. Metasoma: Shining, almost glabrous. Ovipositor length 1.2X forewing length.

Male: Length, 5.5 mm; forewing length, 4.5 mm. Color and structure similar to female.

Holotype: Female, “caged tree infested Dendroctonus, Lincoln N. F., Cloudcroft, N. Mex , #52-1432, C. Hay, Hopk US 34218-M-3” ( USNM).

Other specimens examined: USA: NEW MEXICO: Two male paratypes with same data as holotype ( USNM); Lincoln N.F., 7/2/62, Hopk . US 37240-F, Pinus ponderosa, J. F. Chansler, Collector (4 ♀♀, USNM) .

Host: According to label data, specimens emerged from caged trees infested with Dendroctonus sp. , and another specimen labeled, Pinus ponderosa . Notes from the Hopkins’ cards suggest that some specimens emerged from trees infested with Dendroctonus adjunctus BLANFORD (Scolytidae) , and that all were associated with Dendroctonus . CARLSON (1979) believed that D. adjunctus was the likely host.

Remarks:

This small black species lacks reticulate or carinate sculpture; all sculpture is the fine, dull microsculpture of the head and mesosoma. Lengths of specimens examined are all similar.

Figures

Figs 39-41: Aulacus aneurus. 39Xead, front. 40Xead, dorsal. 41 Mesosoma, dorsal.