Meeting Abstract
Interspecies social behaviors have traditionally been challenging to study because they are difficult to reconstitute in lab. Here, we demonstrate a stereotyped, robust interspecies grooming program for study of social behavior. Sceptobius lativentris is a host specific guest rove beetle which infiltrates colonies of the velvety tree ant (Liometopum occidentale). The beetle is the quintessential social parasite: it dies rapidly when isolated from ants, has lost its wings and disperses on ant trails, and grooms host ants to steal their nestmate recognition pheromones (CHCs), which it uses to disguise inside colonies. Using infrared illuminated behavioral arenas, we have reconstituted the beetles’ stereotyped grooming program in lab which we have annotated with deep learning tools. Though S. lativentris exhibits strict host specificity in nature, it promiscuously grooms divergent species of ants. It does not, however, groom a hemipteran which peripherally associates with L. occidentale. We hypothesize that a core set of cuticular pheromones conserved in ants provide the odor cue triggering S. lativentris social behavior. To test this, we employed a robotized ant-beetle interaction arena which allows application of ant chemicals to a moving dummy object. This arena gives a controlled set up to demonstrate the necessary and sufficient cues for S. lativentris grooming. In addition to establishing the behavioral tractability of S. lativentris as a model system of social symbiosis, we have also worked to establish molecular tools for the beetle. We performed RNA sequencing of the beetle and olfactory structures (legs, antennae), assembled its transcriptome, and annotated odorant and gustatory receptors. Together, these behavioral and molecular tools establish an exciting new system to investigate social symbiosis.
