Guardians of the canopy: two new turtle ant species (Hymenoptera: Formicidae: Cephalotes), from Ecuador Choco and Amazonia, revealed by morphology and DNA barcoding

Abstract

We describe two new species of arboreal ants of the genus Cephalotes Latreille, 1802, from Ecuador: Cephalotes esthelae Ilguan & Troya, sp. nov. and Cephalotes sacha Yumbay & Troya, sp. nov. The former, a member of the grandinosus-group, was collected from lowland Choco and Amazonian forests, while the latter, belonging to the atratus-group, is an inhabitant of the Amazonian region, including Yasuni National Park. Diagnoses and detailed morphological descriptions of workers and soldiers are provided, illustrated by high-resolution images. Species identification was further corroborated with mitochondrial CO1 sequences, which confirmed their distinctiveness from morphologically similar congeners. Both species exhibit unique combinations of mesosomal and gastric characters. In addition, we provide the first description of the soldier of the rarely collected C. dentidorsum De Andrade, 1999. These discoveries expand the known diversity of the genus in Ecuador to 33 species, highlighting this regions role as a hotspot for Neotropical myrmecofauna. A fully illustrated key and checklist of all Cephalotes species known from Ecuador is also presented. The new taxa occur in well-preserved but increasingly threatened forests, ecosystems subject to high rates of deforestation and mining activity, potentially endangering their populations. The integration of molecular and morphological evidence provides a robust framework for delimiting species such as in this morphologically complex and species-diverse genus. We highlight the need of further exploration of under-collected regions such as the Choco and Andean-Amazonian foothills. Continued taxonomic and molecular investigations will be crucial to elucidate phylogenetic relationships, assess biogeographic barriers such as the Andes, and inform conservation strategies for Ecuadors arboreal ant fauna.