Important for normal assembly of actin bundles during bristle formation. Colocalizes with actin filaments. RNAi-mediated knockdown results in abnormal bristle morphology. The bristle ridges are shallower than wild-type and become nonparallel and disorganized near the tip. The tip of the bristle is swollen giving it a javelin-like appearance. In 13% of animals the posterior scutellar bristles are fused.