Food Quality, Larval Consumption, and Growth of Klapopteryx kuscheli (Plecoptera: Austroperlidae) from a South Andes Stream

ABSTRACT

The effect of food quality, measured as leaf resistance and carbon:nitrogen ratio, on the consumption and growth of the plecopteran Klapopteryx kuscheli was analyzed through an in situ experiment. Leaves from seven different tree species were used in feeding trials with intermediate sized K. kuscheli larvae. We used leaves from both deciduous and evergreen species, which exhibited a wide range in C:N ratio as well as leaf resistance. After 30 days, leaf consumption and larval growth were estimated for each of the 119 experimental units. Results showed that K. kuscheli was unable to consume tough leaves (leaf resistance higher than 300 g mm⁻²). Among deciduous species, consumption was proportional to C:N ratio showing a compensative strategy on leaves with higher C:N ratio. Nevertheless, consumption rate did not compensate for growth as ingestion was inversely related to food quality. Native deciduous plant species were of low quality for larval growth and efficient food conversion, and this may have ecological implications for both secondary production and life cycle length in detritivore-shredders inhabiting Andean low-order canopied streams.