Food Plant: Arctium lappa (Greater Burdock), A.minus (Lesser Burdock)

Mine: Summer

Notes: An internal stem borer. The larva makes a short leaf mine into the midrib and then down into the main stem, forming a long channel in the pith. The larvae feed throughout the summer with pupariation taking place in the autumn. The adults emerge the following spring. Plants below 2 feet in height contain few feeding channels or puparia. Stems >20mm diameter have more feeding signs than narrower stems. Two pupariae are shown. Puparia, which are orange yellow, are found at various points within the stem. Puparia turn whitish grey after emergence of the adult. The adjoining posterior spiracles have processes with 16-22 bulbs and also a strong central horn. Probably an under recorded species.

Data: 18.xi.2023, Denver, Norfolk, VC28

Image:© Rob Edmunds