Pea Aphid (Homoptera: Aphididae) Biology on Glandular-Haired Medicago Species 1

Abstract

The biology of Acyrthosiphon pisum (Harris) was studied through one generation on six wild-type, glandular-haired Medicago species and two cultivars (‘Vernal’ and ‘Team’) of M. sativa L. Pea aphids were confined to the apical 10 cm of stem terminals during testing. In comparing growth and development of the pea aphid on glandular-haired species with ‘Vernal,’ significant differences were noted: the pea aphid on glandular-haired species survived fewer degree-days Celsius, produced fewer young at a lower rate of reproduction, and had a lower rate of nymphal development. Also, pea aphid 2nd and 3rd instars preferred the basal one-third of the 10-cm stem terminals on glandular-haired species and the apical one-third of the 10-cm stem terminals on ‘Vernal’ and ‘Team.’