Ja. Mann et al., MOVEMENT OF APTEROUS SITOBION-AVENAE (HOMOPTERA, APHIDIDAE) IN RESPONSE TO LEAF DISTURBANCES CAUSED BY WIND AND RAIN, Annals of Applied Biology, 126(3), 1995, pp. 417-427
The effect of wind and rain on initiation of dispersal and subsequent
distances moved by apterous Sitobion avenae was quantified in five lab
oratory experiments. Wind duration and type (steady and gusting), rain
duration and intensity, and a combination of wind and rain were inves
tigated. With increased duration of wind there was an increase in the
average distance aphids moved. There was less movement when aphids wer
e exposed to gentle gusting, than to steady wind or strong gusting. Wi
th increased duration of rain there was an increase in the proportion
of aphids lost from plants. Under heavy rain, the proportion of aphids
off the release plant, the distance moved by them and the proportion
of aphids lost, was greater than for drizzle or light rain. When wind
and rain were compared, rain had the greater impact on aphid dispersal
. It was concluded that leaf disturbances caused by strong gusts of wi
nd or large rain droplets are of considerable importance in the initia
tion of aphid dispersal, but that wetness alone is not.