A novel set of traits to describe Collembola mouthparts: taking a bite out of the broad chewing mandible classification

The use of functional traits in arthropod ecology has gained in popularity and could be a valuable tool to predict consumer-resource interactions among soil invertebrates. Currently, Collembola feeding strategies are categorized very broadly with either piercing-sucking or chewing mouthparts, despite the diversity of resources they consume. This study described and measured a new set of Collembola mandibular traits in order to better discriminate chewing species based on their mouthpart morphology. Then, we evaluated whether these consumer traits covaried with various litter quality resource traits (physical, chemical or microbial). Out of our 50 studied species, 42 clustered significantly in seven new chewing mandible functional groups. Neither body length, nor phylogeny, were adequate proxies for this set of mandibular traits given tremendous variation across closely related species. Furthermore, when covariation with litter traits occurred, Collembola mandibular traits explained just as much covariation as species composition. These novel traits describing Collembola mouthparts could be a promising venue for predicting feeding interactions of Collembola and their resources.