Electrical Measurement of Feeding by the Strawberry Aphid on Susceptible and Resistant Strawberries and Nonhost Plants

Probing behavior of the strawberry aphid, Chaetosiphon fragaefolii (Cockerell), whose principal natural host is strawberry ( Fragaria spp.), was measured electrically. The plants tested were strawberry, Fragaria × ananassa Duchesne, cv. ‘Northwest’ and F. vesca L. var. ‘Alpine’ (susceptible hosts), strawberry selections ‘72-69-T’ and ‘Del Norte’ clone of F. chiloensis L. (resistant strawberries), and red raspberry, Rubus idaeus L., and broadbean, Vicia faba L. (nonhost plants). Although the aphid tended to probe less on broadbean, some individuals ingested for long periods of time. Feeding for 3- or 12-h periods was similar on all the other test plants. In longevity studies, the aphid survived well on Alpine strawberry but poorly on 72-69-T and Del Norte strawberries, raspberry, and broadbean.