LIFE CYCLE AND REPRODUCTION OF RHOPALOSIPHUM PADI (L.) (HOMOPTERA: APHIDIDAE) ON WHEAT IN THE LABORATORY1

Abstract

The life span and reproduction of the bird cherry-oat aphid, Rhopalosiphum padi (L.), was studied in chambers at 25 ± 0.5°C and a 12:12 hr light:dark cycle on winter wheat (Triticum aestivum L. em Thell.) cvs. Blueboy, Monon, Seneca, Knox 62, and Arthur 71, and oats (Avena sativa L.) cv. Clintland 64 (C64). The life cycle, wing formation, fecundity, and longevity of R. padi varied significantly among cultivars.Apterae and alatae longevity were similar on the same cultivar. Wingless R. padi lived for 24.9–29.6 days on wheat cultivars and 33.1 days on C64 oats. The alatae lived for 26.6–28.3 days on wheats and 33.2 days on C64 oats. Differences in the longevity of alatae were highly significant (P ≤ 0.01) between C64 and the wheats Knox 62 and Seneca, as well as between Blueboy, Arthur 71, and Monon.On wheat, the reproductive period lasted longer in wingless (24.9–29.6 days) than in winged (26.6–28.3 days) aphids. Clintland 64 oats were the most suitable host for R. padi (apterae and alatae mean progeny of 38.7 nymphs per famale). On wheat, progeny production ranged from 6.4 nymphs on Seneca to 24.0 on Blueboy. The least suitable hosts for R. padi were the Seneca and Know 62 cultivars. These cultivars showed a relative antibiosis type of resistance to the bird cherry-oat aphid. Selections from Seneca and Know 62 may be of use in wheat breeding programs for plant resistance against R. padi.