Fig. 1.
Biological and host-seeking differences between two selected pea aphids. Body length, hind tibia length (third pair of legs) (A) and weight (B) differences between two selected host-seeking wingless strains of Acyrthosiphon pisum. (C) Proportions of aphids that reached the host leaf disc after 24 h. (D) Percentage increase of aphids that located in every two hours in relation to total numbers of aphids on the host leaf disc in 24 h. Values represent mean±s.e.m. from independent determinations; *P<0.05, **P<0.01 (Student's t-test in B and C; parameter estimates of general linear model repeated-measures in D). P values in D derived with repeated measures testing.