Viability and Fecundity of Alate Alienicolae of Aphis Fabae Scop. After Flights to Exhaustion

Abstract

1. Laboratory-reared 24 hr.-old alate alienicolae of A. fabae were flown for variable periods, but all to apparent exhaustion; their subsequent longevity and fecundity on broad beans, or their survival times during starvation, were compared with controls. 2. Adult longevity, reproductive rate and capacity, and nymph viability were similar in exhausted and control aphids that settled on host plants after flight. Mean adult life was 31 days in exhausted aphids and 32 days in the controls. Both exhausted and control aphids produced an average of 84 larvae per adult. 3. The only major difference noted between exhausted and control aphids that fed after flight was a reluctance, or inability, of exhausted aphids to fly on the following day. 4. Exhausted aphids starved after flight lived for a significantly shorter time (mean of 30 hr.) than control aphids starved without flight (55 hr.). 28% of the exhausted and 88% of the control aphids could take-off on the next day. 5. The results indicate that long migratory flights are unlikely to affect the reproductive potential of aphids, and that alate alienicolae of A. fabae, having settled on a suitable host after an exhaustive flight, are unlikely to fly again.