Winged forms migrate to other hosts in late spring. During these migratory flights, aphids may spread virus diseases from infected volunteer plants and weeds to healthy crop plants. Movement between host plants continues through summer and fall. In southern states, the aphids are nearly all females. Successive generations of females, mainly wingless, are produced throughout the year.
Winged migrants develop whenever overcrowding occurs or food becomes scarce.
Many generations are produced each year. Fungus diseases, high temperatures, damp weather, and hard rains also reduce aphid populations. Cultural practices are helpful in avoiding aphid infestations. The purchase of certified seed from areas free of virus is also a good preventative measure. A number of insecticides are available to control aphids on a wide variety of crops.