Figure 1

Orientation behaviour of N. viridula males. (a) Schematic presentation of the experimental set-up showing the positions of female calling song (FCS) delivery to the bean plant. The male was placed on the top stem to avoid bias and the side of stimulation was randomly selected. (b) Proportions of males making correct or wrong first directional choice at the 4-way crossing. “Chance” indicates the probability of choosing the same branch first at random, i.e. in absence of detectable direction cues (0.25). FCS₁ and FCS₂ indicate the first choice with the respective FCS treatments (for details see Materials and Methods). N = number of males tested. Asterisks indicate a significant difference between correct and random choice (Chi-square test, *P < 0.05; **P < 0.01).