Decoding Anotylus (Thomson 1859) Beetle Diversity: DNA and External Morphology Match in Area de Conservacion Guanacaste, Costa Rica

Taxonomy underpins biological research because names are needed for comparative analysis, conservation status, and public communication. Despite this, many species remain undescribed and are therefore vulnerable and unprotected, particularly in the tropics. Neotropical Staphylinidae beetles (Coleoptera) are among the insect groups most likely to contain significant unknown and/or cryptic diversity. Here we used an integrative taxonomic framework to conduct a preliminary review of one particularly diverse genus of Staphylinidae (Anotylus) in Area de Conservacion Guanacaste, northwestern Costa Rica. We began by DNA barcoding novel collections and using Barcode Index Numbers (BINs) as an estimate of taxonomic diversity; we found 18 provisional new species. We augmented this genetic analysis with a morphometric analysis of adult morphological characters and found that we could differentiate most provisional species by external morphology as well as by elevation of collection. All the most abundant species could be differentiated from each other by differences in body size. One BIN included slight (similar to 1%) genetic variation that corresponded with some morphological differentiation suggesting the existence of two species within a DNA BIN. Our results support the efficacy of DNA barcoding collections of tropical insects as an effective biodiversity estimator, one that can be used as a primer for integrative taxonomic studies using BINs as species hypotheses.