FLUCTUATING ASYMMETRY AND PARASITISM IN 6 NEW-ZEALAND INSECTS

Positive associations between parasitic infections and developmental i nstability are often reported in the literature. In some cases, develo pmentally unstable individuals are of lower genetic quality and more p rone to infection, whereas in other cases, parasites appear to directl y cause developmental instability. We determined whether parasitism co rrelated with fluctuating asymmetry in femur length, a measure of deve lopmental instability, in two species of cockroaches harbouring benign nematodes, and four species of grasshoppers infected with harmful gre garine protozoans. We found no evidence that the more asymmetrical ind ividuals were more heavily parasitized, in either of the six insect sp ecies. These results provide several exceptions to the pattern general ly reported in the recent literature, and suggest that, at least among insects, fluctuating asymmetry and parasitism are not always associat ed. (C) Elsevier, Paris.