Field assessment of the efficiency of two sampling techniques for adult caddisflies (Insecta: Trichoptera)

Abstract

Sampling small-sized, nocturnal amphibiotic insects poses practical questions onto which technique should be used. This is the case of Trichoptera adults, which have been sampled mostly by using pan, light sheets associated with UV lamps. The urgency of selective and efficient sampling, however, requires quantitative comparison of different methods. We evaluated in situ efficiency of two techniques for sampling Trichoptera adults – light pan traps and light sheet attraction, both attached to UV and white lights – in a protected area in a rainforest fragment. The rarefaction curves indicate that sampling was efficiently robust to represent the local assemblage for both techniques. No significant differences were observed in caddisfly diversity according to the method. Overall, sex ratio of the adults did not differ, as both males and females were caught in similar proportions. We conclude that both techniques can be used for short-term inventories of caddisfly diversity, especially in areas where collection licences limit the number and range of sampled insects. Advantages and disadvantages of each technique, regarding representativeness, effort, selectiveness, and efficiency are discusses in this study.