Published online by Cambridge University Press: 31 May 2012
The fact that most species of aphids at some time each year develop winged forms and that these winged aphids move from plant to plant is common knowledge. That the development of aphid infestations, on annual plants grown from seeds and on certain other plants commercially grown from cuttings of underground tubers, generally results from visits made by winged aphids is also well known.
* Contribution No. 2038, Division of Entomology, Science Service, Department of Agriculture, Ottawa, Canada.