The role of microorganisms in the diet of Verger cf. limnophilus (Trichoptera:Limnephilidae) larvae in a Patagonian Andean temporary pond.

DÍAZ VILLANUEVA, V. & TROCHINE, C.

WETLANDS

The Society of Wetland Scientists

Lugar: Lawrence; Año: 2005 vol. 25 p. 473 - 479

0277-5212

Abstract: The importance of fungi and bacteria attached to leaf litter in the diet and growth of shredders in flowing waters is well-documented. This study focuses on the role of microorganisms colonizing submerged leaf litter in the diet and growth of Verger cf. limnophilus (Trichoptera: Limnephilidae) larvae in a Patagonian Andean temporary pond (Fantasma pond, 418079S, 718279W). First, the feeding habits were analyzed through an experiment that compared consumption of CPOM and FPOM. Once we determined that V. cf. limnophilus consumed CPOM, we performed an experiment to compare consumption and growth rates of larvae fed on non-autoclaved and autoclaved decaying leaves. Algae was the most abundant group to colonize leaf surface, comprising 74% of total biovolume. Consumption of non-autoclaved leaves was fourfold that of autoclaved treatments, which produced negative insect growth rates. Although V. cf. limnophilus processed leaves by shredding, microorganisms living on the leaf litter were found to be an important food resource. As microbial biomass represents a small percentage of the ingested food (0.22 %), V. cf. limnophilus appears to process relatively large quantities of detritus to obtain sufficient resources for growth (100 mg leaves to grow 3 mg). Key Words: shredders, microorganisms, temporary pond, organic matter cycling, algae