Figure 4

Interpopulation variation in the camellia pericarp thickness at which a half of weevil attacks are successful. (A) In each population, the pericarp thickness at which weevil excavation attempts are expected to succeed at a probability of 50% (BS₅₀; ± 95% CI) was calculated from a logistic regression (Fig. 3; Table 2). A population (Fukagawa) was excluded due to lack of a significant relationship between camellia pericarp thickness and the success of weevil attacks. (B) Difference between mean pericarp thickness and BS₅₀. (C) Relationship between the degree of pericarp evolution and the success of weevil attacks. The proportion of successful excavations of camellia pericarps by camellia weevils was regressed on the difference between mean pericarp thickness and BS₅₀. Solid line represents a significant reduced major axis regression.