Allometry of size in three species of biting midges (Diptera, Ceratopogonidae, Culicoides)

Summary

Using homogeneous samples, allometry of size is studied in the antennae, hind legs and palps of female Culicoides pulicaris, punctatus and impunctatus, to determine whether any taxonomically important characters show proportional changes with size. A tendency for isometry is found in the apical segment of the legs and palps in pulicaris and punctatus. In C. impunctatus the only occurrence of allometry is seen in the apical segments of the antenna.

Allometric gradients for the three appendages are calculated including the 95% confidence intervals. Generally, these limits are rather large, and many apparent deviations from isometry are not significant. This provides a good example of the need to use confidence limits in studies of allometry. The allometric gradients are very similar in pulicaris and punctatus, in contrast to those of impunctatus, suggesting that no general description of allometry can be applied to the species group.