This file contains the raw data for central brain, mushroom body calyx and antennal lobe volumes for Aglais urticae, Aglais io and Swedish/English Polygonia c-album. The first column specifies the treatment the butterfly female underwent (i.e. Newly eclosed, Unmated, Simple or Complex). The second column specifies the species identity. In the 3rd-5th column the central brain volume, mushroom body calyx volume and antennal lobe volume are given respectively. The 6th and 7th column describe the relative mushroom body calyx volume and relative antennal lobe volume respectively, both corrected for central brain size.