The effect of prey density on the developmental time of larvae of an aquatic beetle: Tropisternus setiger (Insecta, Coleoptera: Hydrophilidae).

PEREYRA, D. & M. ARCHANGELSKY.

HYDROBIOLOGIA

Springer Science

Año: 2007 vol. 586 p. 367 - 372

0018-8158

Abstract Predaceous larvae of the water scavengerbeetle Tropisternus setiger (Germar) arecommon inhabitants of variable environments inwhich prey availability may vary widely. Weconducted laboratory experiments to assess theeffect of prey density on developmental times andsurvivorship of the preimaginal stages of T.setiger. We also examined the effect of thenumber of consumed prey on the larval size ofinstar III. Four different prey densities (one, two,four, and eight preys a day) were tested and bothdevelopmental time and survivorship differedsignificantly among them. Larvae fed one or twopreys daily showed a longer developmental timeand a lower survivorship than larvae fed four oreight preys a day. Moreover the consumption offour preys a day increased larval developmentalsuccess, and to consume one prey a day affectedsurvivorship through the larval period. On theother hand, prey density had no effect on the finallarval size.