ARGENTINA Ichnoentomology: a unique approach to insect research

Ichnoentomology can be defined as the study of insect behavior through the analysis of their traces. These traces are commonly found in soils, wood, leaves, bones, and fruits. If they overcome the taphonomic barrier, insect traces may be preserved in paleosols, petrified wood, fossilized leaf compressions or impressions, as well as in fossilized bones and fruits. Trace fossils provide physical evidence of how and where insects of the past fed, reproduced, and moved, enabling the reconstruction of their evolutionary history and the paleoenvironment they inhabited. This contribution summarizes the study of extant insects carried out by the División Icnología of the Museo Argentino de Ciencias Naturales over the past 30 years. The study of nesting behaviors, nest structures, pupation chambers, and/or cocoons of 135 insect species and other arthropods has enabled the interpretation of numerous trace fossils produced by phylogenetically related fossil species. Among the most notable recent discoveries are Cellicalichnus krausei, a 100 Ma bee nest attributed to the tribe Halictini, and Racemusichnus jacobacciensis, the largest known solitary insect trace. In commemoration of the 100th anniversary of the Entomological Society of Argentina (SEA), this work aims to highlight a different perspective in the study of insect behavior.