Meeting Abstract

P2.115  Saturday, Jan. 5  Functional morphology and efficiency of the antenna cleaner in Camponotus rufifemur ants HACKMANN, A*; FEDERLE, W; University of Cambridge; University of Cambridge ah658@cam.ac.uk

In the course of evolution insects have developed a variety of strategies to reduce surface contamination, which can inhibit physiological functions. For example, many insects regularly clean their antennae with specialized cleaning devices on their front legs. In Camponotus rufifemur ants, the antenna cleaner consists of a notch on the basitarsus facing a spur at the end of the tibia. Both components each bear a ‘comb’ and a ‘brush’. Both combs consist of one row of stiff, regularly spaced cuticular outgrowths, whereas the brush structures bear multiple rows of flexible setae. Video recordings of the ants’ cleaning behaviour showed that the spur is used to keep the antenna in contact with the tarsal notch. When the tibial spur was removed, insects were unable to clean the antenna. In order to investigate the detailed roles of spur and notch during antenna cleaning, we simulated cleaning movements using a motor positioning stage by stroking cleaning structures over antennae that had been artificially contaminated with fluorescent particles. Measurements of particle density on the antenna before and after simulated cleaning movements revealed that the tarsal notch removed particles more efficiently than the tibial spur, but both notch and spur removed more than 60% of the particles with the first cleaning stroke. Removal of brush and comb from the cleaning devices strongly reduced cleaning efficiency for both notch and spur, suggesting that these surface structures are essential for cleaning.