Prolegs and attachment of Simulium vittatum (sibling IS-7) (Diptera: Simuliidae) larvae

A study of prolegs of Simulium vittatum larvae by scanning electron microscope reveals two supposed campaniform sensilla on the thoracic proleg, and tubercles on hooks of the posterior proleg. These tubercles could prevent hooks from dislodging from the pads of silk to which larvae attach. Inferences based on study of protracted and retracted prolegs, and of prolegs still attached to silk, suggest that bristles of lateral plates of the thoracic proleg help larvae to extricate hooks of that proleg from silk. A similar study of posterior prolegs suggests that the anal sclerite helps larvae to attach posterior hooks of the posterior proleg to pads of silk.