• Size;
  • host shift;
  • insect;
  • parasite;
  • flower;
  • Thysanoptera;
  • Meligethes;
  • Tephritidae;
  • Siphonaptera;
  • Phthiraptera


  • 1
    Regressions of adult insect size on host size were tested. The analysis was restricted to highly host-specific insects that had thus been exposed to a narrow range of host size.
  • 2
    The phylogenetic regression method was used to analyse the data, so as to allow for the possible phylogenetic effects in cross-species data.
  • 3
    Significant positive regressions were found in all the groups tested: female flower thrips, Meligethes species of pollen beetle, tephritid flies, and male and female fleas. They were also found by standard regressions within. and between Actornithophilus species of bird louse.
  • 4
    The regression of thrips size on pollen size was not significant, providing evidence against a hypothesis involving food size.
  • 5
    The regression of flea body size on host hair/feather length was significant, which is consistent with a hypothesis involving the size of spaces on the host.
  • 6
    The relationships may have implications for the understanding of evolutionary host shifts.