Local feeder / borer (Lepidoptera: Tortricidae) in stems of Cannabis

In mid-July 2017, I found a larva feeding on stem interior tissue within an externally visible fusiform stem swelling on a wild plant growing in a disturbed area. There was a small hole in the swelling capped with a wad of frass. The larva was whitish with a jet black head capsule and dark thoracic shield.

Also, in summer 2024, I photographed similar swellings, also on wild plants growing in a disturbed area, including one swelling from which the pupal exuviae of the emerged moth were protruding.

The species-level identification is tentative, based on the host plant, larval habitus, and life history summary by Wolgemuth et al. (2017).