Macrosiphum ambrosiœ (Thomas).— Siphonophora ambrosiœ, Thomas, Bull. Ill. State Lab. Nat. Hist., 1878, p.4.
Found at Pecos, New Mexico, on Lactuca. The following account is based on the Pecos specimens:
Very dark brown, very shiny; legs, antennæ and nectaries black, except that the basal part of legs, to near middle of femora, is brownishwhite; stigma pale green; cauda of winged ♀ yellowish-white.