highly significantp<0.001
In contrast, species differences in the proportion of aphids that fell from the host plant as a result of chill coma were highly significant (χ 2 2 = 20.80 p<0.001), with significantly more M. dirhodum falling from the plant as a result of chill coma, and significantly less R. padi than expected (relative proportions for M. dirhodum , R. padi and S. avenae are 0.45, 0.02 and 0.21 respectively).