alternative definition added about 15 years ago by Istvan Miko
Narrow, usually dark thickenings of a wing arising at the wing base and branching towards the apex (see also nebulous, spectral, tubular veins, and morphology section for naming of veins).
Reference: Goulet, H., and J. T. Huber. 1993. Hymenoptera of the World: An Identification Guide to Families. Research Branch, Agriculture Canada Publication 1894/E., Ottawa, ON 668 pp.
Cross reference:
None provided.