Ceruraphis viburnicola

The snowball aphid is found from the Northeast to parts of Canada. This insect overwinters on its host plants in the form of eggs that are laid on the twigs and buds the previous fall. Egg hatch occurs at the same time as host plant buds are opening in the spring. The young, newly hatched aphids begin to feed and develop on the new buds of their host. Mature snowball aphids are approximately 2.5 mm long and ash gray or bluish white in color. They are plump and round and look like they are coated in powdered sugar. At this time of year, the mature individual is known as a stem mother, and she is capable of producing large numbers of immature snowball aphids without sexual reproduction. Young aphids (immatures) are whitish or light green in color. Feeding from the snowball aphid causes leaves to be distorted and even on occasion the leaf stems to be bent. This happens within approximately 3 weeks of budbreak. By approximately 2 months following egg hatch, all of the snowball aphids leave their viburnum hosts, presumably for a secondary host whose identity is not certain at this time. In roughly September, winged snowball aphids return to viburnum where they give rise to the sexual form of the aphid that will reproduce and lay the overwintering eggs. Eggs are dark in color and shiny. The snowball aphid (Ceruraphis viburnicola) is a different species than the viburnum aphid (Aphis viburniphila) which is present with viburnum year round, yet does not cause leaf distortion on the host. Black bean aphids (Aphis fabae) may cause leaf distortion on certain species of viburnum.