A test of the preference-performance hypothesis with stream insects: Selective oviposition affects the hatching success of caddisfly eggs

Abstract

Under the preference-performance hypothesis (PPH), oviparous females select oviposition sites that optimise the fitness of their offspring (eggs or larvae). The resulting distribution and fitness of offspring may have knock-on effects for population distribution patterns and dynamics during larval and adult stages. We tested the PPH for Australian caddisflies from two genera (family: Hydrobiosidae) that oviposit in different flow conditions. Apsilochorema spp. oviposit in slow flowing water, whereas Ulmerochorema sp. favour fast flows. We expected hatching success to be higher in velocities favoured by ovipositing females. In a field experiment, newly laid egg masses of each species were exp..