Estimating species diversity in a guild of Neotropical skippers (Lepidoptera: Hesperiidae) with artificial lures is a sampling problem

Butterflies are frequently used to investigate Neotropical diversity, but the family Hesperiidae is almost never employed as a focal group. Sampling Hesperiidae with artificial lures has been used to assist in species richness estimates of males that use bird droppings as a resource, but its effectiveness for estimating total hesperiid site diversity is unknown. This study characterises species richness and abundance in a diverse assemblage of Hesperiidae sampled at artificial lures. Sampled and estimated richness among taxonomic subsets were compared to the known site richness. These comparisons are used to assess artificial lures as a method for sampling total richness of Hesperiidae. We tested for potential differences in attraction in lures placed with and without the presence of army ant swarms. Five years of intermittent sampling with lures recovered 65% of the known Hesperiidae species richness at the study site. We found the subfamilies were differentially attracted to lures, where 86% of Eudaminae, 56% of Hesperiinae and 55% of Pyrginae species known from the site were recovered by lures. Species accumulation and taxonomic diversity differed among lures placed alone, and those placed in the presence of army ants. Our results suggest that sampling with artificial lures can be used to estimate diversity of Neotropical Eudaminae and a few tribes of Hesperiinae at some sites. Available evidence indicates that Hesperiidae feeding at bird droppings is predominately a Neotropical phenomenon. Finally, we conclude that estimating diversity in Neotropical Hesperiidae will require long-term studies that use multiple sampling techniques.