Why do Potamophylax Cingulatus (Steph.) (Trichoptera) Larvae Aggregate at Pupation?
In stream-living Potamophylax cingulatus, current velocity was found to be an ultimate factor in guiding settlement of the larvae prior to pupation, areas of high current velocity being avoided. In areas suitable for pupation, i.e. in a low current regime, the larvae formed aggregations only under certain stones. Most pupae were found in large (> 40 inds.) aggregations, where also hatching success was highest. Infestation by a chironomid larva, Polypedilum fallax Joh., peaked at intermediate aggregation size. We suggest pupal aggregations to be formed in order to reduce the risk of becoming a victim of the chironomid.
KeywordsCurrent Velocity Large Aggregation Hatching Success Infestation Rate Downstream Part
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- Cullen, J.M., In Proc. 7th Int. Om. Congr. Helsinki, pp. 153–157, 1969.Google Scholar
- Dratnal, E., Bull. Acad. Pol. Sci. Biol. 27: 183–193, 1979.Google Scholar
- Parker, C.R. and Voshell, J.R., Environ. Entomol. 8: 808–809, 1979.Google Scholar
- Scott, D., Arch. Hydrobiol. 54: 340–392, 1958.Google Scholar
- Wilson, E.O. Sociobiology — the New Synthesis. Harvard University Press, Cambridge, Massachusetts, 1975.Google Scholar