Stem borer (Diptera: Agromyzidae) in Lapsana [0306]
| Order | Diptera |
|---|---|
| Family | Agromyzidae[T,P] |
| Lower taxon | Melanagromyza |
| No. spp. involved | One confirmed |
| Feeding mode | Stem borer |
| Host plant | Nipplewort, Lapsana communis (Asteraceae) |
The larva tunnels in the layer of pith lining the interior of the hollow stem. Pupation occurs in the pith, with an exit window prepared nearby in the outer wall of the stem. In the example shown below, the puparium was the overwintering stage. The insect is tentatively identified as Melanagromyza sp. based on the color, shape, location, and posterior spiracles of the puparium.
IMG#: 0306-01
Dead stem of host, split open lengthwise, showing raised "molehill" tunnel in pith, running from left to right along the horizontal center line of the image, and ending in a rounded dead-end not far from the right edge of the frame. A second length of tunnel in the pith, created by the same larva, was breached when the stem was split open, exposing the ragged interior of the tunnel; this length of tunnel runs across the entire frame, above the horizontal center line of the image. (Photo date: November 6, 2022)
IMG#: 0306-02
Stem interior, with a small amount of pith scraped away, revealing puparium in "molehill" tunnel in pith.
IMG#: 0306-03
More pith removed, revealing tunnel with puparium inside, along with the exit window in the far wall of the stem. (Photo date: November 6, 2022)
IMG#: 0306-04
Tunnel with puparium and exit window.
IMG#: 0306-05
Detail, puparium in tunnel with exit window nearby.
IMG#: 0306-06
As-yet unused exit window, viewed from the stem interior.
IMG#: 0306-07
As-yet unused exit window, viewed from the exterior of the stem.
IMG#: 0306-08
Exit window, viewed from the exterior of the stem.
IMG#: 0306-09
Cross section of affected stem, showing tunnels in the layer of pith lining the hollow stem interior.
IMG#: 0306-10
Puparium. (Photo date: November 6, 2022)
IMG#: 0306-11
Lateral view, posterior spiracles of puparium, showing strong curved horns.
IMG#: 0306-12
Posterior spiracles of puparium.
Specimen data for images
Coll. 11/06/22, photos same day (01-12).
References
[none]
Page created 01/06/24. Last update: 02/25/25