Leptostigma fasciatum, Archibald & Rasnitsyn, 2023

Archibald, S. Bruce & Rasnitsyn, Alexandr P., 2023, Cimbicidae (Hymenoptera, ‘ Symphyta’) in the Paleogene: revision, the new subfamily Cenocimbicinae, and new taxa from the Eocene Okanagan Highlands, Zootaxa 5278 (1), pp. 1-38 : 21-22

Leptostigma fasciatum n. sp.

http://zoobank.org/ urn:lsid:zoobank.org:act:19480AA6-435A-490A-BB68-644C50F9BD32

Fig. 20 .

Holotype. GSC 142843 ( Fig. 20 ). A mostly complete forewing, missing the apex and the basal portion of cell 1a. Collected by SBA at McAbee ( GSC locality V-016800), May 16, 2001, in the collections of the GSC (Vancouver).

Diagnosis. Distinguished from other species of Leptostigma by a combination of forewing mid-length with dark transverse fascia, including small part of cell 1mcu. Tentatively diagnostic: R+M shorter than 1-M, 2r-rs joins cell 3rm distinctly distal to its middle, 2r-m joins M scarcely basal to 2m-cu, anal cells meet at crossvein (1A and 2A+3A not fused).

Description. Holotype. Forewing length: 11.1 mm, maximum width estimated 4.0 mm, length/width 2.8; membrane lightly infuscate throughout, darker posterior to base of pterostigma; pterostigma narrow, tapering, similar to width of C-R before pterostigma; R+M shorter than 1-M; maximum length of cell 2r shorter than 3r; 2r-rs shorter than Rs between 2r-m, 2r-rs; 2r-m curved, slightly sigmoidal, joins Rs notably basal to 2m-cu joins M, joins M scarcely behind 2m-cu; 1-M straight; cell 1mcu almost square; 3r-m slightly curved; cell 2mcu with M shorter than 1m-cu; 2m-cu curved toward base; cu-a interstitial; anal cells meet at crossvein, with adventitious oblique crossvein in cell 2a.

Remarks. Differs from L. brevilatum n. sp., L. longiclava n. sp., L. longipallidum n. sp., L. longitenebricum n. sp. in having forewing with dark transverse fascia and 2r-m joining M close to 2m-cu. Differs from L. proxivena n. sp. by a more distal position of 2r-rs (distal to middle of cell 3rm), from L. alaemacula n. sp. by anal cells meeting at crossvein (1A and 2A+3A not fused).

Material. Holotype.

Etymology. From the Latin adjective fasciatus, meaning striped, referring to the forewing colouration of the species.

Locality and age. McAbee, British Columbia, Canada, Hoodoo Face beds; mid-Ypresian.

Figures

FIGURE 20. Leptostigma fasciatum holotype GSC 142843, forewing: A, photograph; B, drawing. Scale bar 5 mm.