Electronically monitored cowpea aphid feeding behavior on resistant and susceptible lupins

The feeding behavior of cowpea aphid, Aphis craccivora Koch (Homoptera: Aph ididae) was examined on seedlings of narrow leafed lupin, Lupinus angustifo lius L., and yellow lupin, L. luteus L., using electronic monitoring of ins ect feeding behavior (EMIF). Aphid feeding behavior was first compared betw een resistant (cv. Kalya) and susceptible (cv. Tallerack) varieties of narr ow-leafed lupin. Aphids spent significantly more time in non- penetration a nd stylet pathway activities, and significantly less time in the sieve elem ent phase on Kalya than on Tallerack, suggesting that feeding deterrence is an important component of aphid resistance in Kalya. Aphid feeding on a su sceptible yellow lupin variety (cv. Wodjil) was then compared with that on two resistant lines, one (Teo) with high and the other (94D024-1) with low seed alkaloid content. There were no consistent differences in aphid feedin g behavior between Wodjil and Teo. Total, mean and percentage sieve element phase times were significantly lower, and total and percentage times in no n-phloem phase were greater on 94D024-1 than on Wodjil, suggesting the poss ibility of phloem-based deterrence in 94D024-1.