Behaviour of some low‐flying aphids in wind

SUMMARY Field observations on low‐flying gynoparae of Myzus persicae showed a marked upwind bias of courses in wind speeds between about 0.2 and 1.2 m/s, and of tracks of up to about 0.8 m/s. Progress over the ground was small and the net effect of the upwind bias was loose station‐keeping. Quantitative recordings from Aphis fabae virginoparae in a laboratory wind tunnel 1.2 × 0.9 m in section showed similar station‐keeping behaviour in winds up to about 0.4 m/s. The behaviour comprised upwind orientation and regulation of airspeed according to the wind speed, both reactions being more precise at higher wind speeds. These reactions to wind could be simulated in still air by providing a moving floor pattern. Their role in the field appears to have been underestimated.