Fig. 1

Artificial selection on associative learning ability in N. vitripennis.a Schematic overview of the selection experiment. Females were allowed to oviposit on host pupae placed on either a yellow or blue background. 24 h later, the females were placed in a transparent tube with yellow and blue outer ends. Only females that chose the background colour corresponding to the colour on which they had been trained were used to found the next generation. This procedure was repeated ten generations in four replicate selected lines. Each selected line was paired to a control line that was treated following the same procedure, except that in the control lines, females were randomly chosen from the tested wasps. Nasonia’s after a photo by Jitte Groothuis. b Changes in associative learning ability (mean performance index over four replicate lines) over ten generations of selection in selected and control lines. For details, see [8]