| Abstrakt: |
Biotypes E, G, and H of greenbug, Schizaphis graminum (Rondani), were monitored on susceptible ‘Wintermalt’ and resistant ‘Post’ barley to determine their feeding behavior, developmental time, and fecundity on these cultivars. Overall, ‘Post’ caused significantly greater frequencies of nonfeeding, probing, and salivation events for biotype E than for biotype H. Frequencies of these three events were significantly less on Wintermalt’ than on ‘Post’, and differences among biotypes on ‘Wintermalt’ were nonsignificant. Biotype H spent significantly less nonfeeding time (baseline) on ‘Post’ plants than either biotypes E or G. When compared with biotype E and H, greenbug biotype G spent significantly more time salivating and less time feeding within the phloem on ‘Wintermalt’. Biotype G also took significantly longer to begin reproduction and produced fewer progeny than did E and H on ‘Wintermalt’ barley. This indicates biotype G was less successful in feeding on ‘Wintermalt’ and confirms previous reports about its inability to feed successfully on barley. Both biotypes E and H were relatively more successful in feeding within the phloem on ‘Wintermalt’, but biotype E was less successful than biotype H on ‘Post’ in progeny production. |
