CEREAL APHIDS IN SOUTH DAKOTA .I. OBSERVATIONS OF AUTUMNAL BIONOMICS

Six aphid species[long dash]the corn leaf aphid, Rhopalosiphum maidis (Fitch); oat bird-cherry aphid, R. padi (L.); rice root aphid, R. rufiabdominalis (Sasaki); English grain aphid, Macrosiphum avenae (F.); greenbug, Schizaphis graminum (Rondani); and Forda olivacca Rohwer[long dash]colonized winter wheat in South Dakota during the autumns of 1963, 1964, and 1965. Except for R. padi, no evidence was found of holocyclic overwintering by these species. Subterranean alienicolae of R. padi and R. rufiabdominalis survived into early Dec., but did not overwinter in any of the 3 years.