Differential Reaction of Introductions of Crambe to the Turnip Aphid and the Green Peach Aphid12

When 20 accessions of Crambe abyssinica Hochst. ex R.E. Fries and I of C. hispanica (L.) were tested in the greenhouse to determine the potential importance of the turnip aphid, Hyadaphis pseudobrassicae (Davis), and the green peach aphid, Myzus persicae (Sulzer), as pests of C. abyssinica and C. hispanica , both species of aphids were found capable of causing severe damage to both species of crambe in the proper environment. PL 247310 (an accession of C. abyssinica ) was resistant to the turnip aphid; all plants tested of other accessions of crambe were susceptible. Also, all plants tested of all accessions were susceptible to the green peach aphid. An infestation of turnip aphids will cause more damage to susceptible crambe than a comparable infestation of green peach aphids.