Stem miner (Diptera: Agromyzidae) in Pastinaca

Record Details

Record no.:	0622
Feeding guild:	Stem miner
Taxonomy:	Diptera: Agromyzidae: cf. Ophiomyia sp.
Stages observed:	trace, puparium
Distribution observed:	IA
Hosts in Pastinaca:	P. sativa (wild parsnip)

I found a single example of this stem miner in July 2023. The mined area and puparium were in the stem of a branch of the infructescence underneath the umbel. The mine extended over a region of the stem approximately 15cm in length. It was a whitish color with irregularly deposited splotches and spotty lines of dark green or black frass. The yellowish-brown puparium was formed just under the epidermis with the anterior spiracles protruding. Identification of the insect to genus is tentative.

Featured Images

[?] Top

narrow, ridged green stem with whitish discoloration in upper part resulting from Ophiomyia larva's mining — Image #: 622-01 Upper stem of wild parsnip with stem mine. (Photo date: July 31, 2023)

the straw-colored puparium rests under the transparent epidermis, causing the epidermis to bulge out slightly — Image #: 622-02 Puparium under stem epidermis.

the front of the puparium is broadly wedge-shaped and the rear is more tapered — Image #: 622-03 Detail, puparium under stem epidermis.

the epidermis bulges over the dorsoventrally flattened puparium — Image #: 622-04 Lateral view of puparium in stem.

the puparium sits under the epidermis, which has turned whitish due to the larva's mining — Image #: 622-05 Lateral view of puparium in stem.

the pale mine is speckled with broken lines and irregular patches of dark frass — Image #: 622-06 Portion of stem mine.

this portion of the mine ends sharply near the right edge of the image, giving way to undisturbed, green stem tissue — Image #: 622-07 Another portion of the stem mine.

Page created: June 4, 2026. Last update: June 4, 2026