Stem borer (Lepidoptera: Momphidae) in Circaea [0149]

Order	Lepidoptera
Family	Momphidae[M,L,P,A]
Lower taxon	Mompha luciferella
No. spp. involved	One confirmed [1-C]
Feeding mode	Stem borer
Host plant	Enchanter's nightshade, Circaea lutetiana (Onagraceae)

Larva tunnels in the stem interior and may enter the roots as well. Adults were reared from overwintered dead stems in spring 2021, and determined to be M. luciferella by T. Harrison (pers. comm.). Short, shallow, narrow tunnels in the middle to upper reaches of living stems, found in summer, are suggested here to be the work of early-instar M. luciferella based on the finding of an apparent Lepidoptera head capsule in one of the tunnels, but this attribution is tentative and requires confirmation.

IMG#: 0149-01
Larva overwintering in senesced stem of the host. (Photo date: October 26, 2020)

IMG#: 0149-04
Overwintered dead stem of host in spring, after successful emergence of the adult moth, showing exit hole in wall of stem. (The outermost layer of stem tissue was removed for this photo.)

IMG#: 0149-05
Overwintered dead stem (dissected) in spring, after adult's emergence, showing pupal exuviae in cocoon and frass. (Photo date: May 13, 2021)

IMG#: 0149-07
Reared adult. (Photo date: May 12, 2021)

IMG#: 0149-10
Shallow, externally visible tunnel in middle to upper part of living stem of host during summer. An apparent Lepidoptera head capsule (see image 0149-13, below) was recovered from inside the tunnel about 15mm from the entry/exit hole, hypothesized (but not confirmed) to be from an early instar of *Mompha luciferella*. Older larvae of *M. luciferella* finish their work in deeper tissues of the stem. (Photo date: August 2, 2022)

IMG#: 0149-12
Entrance / exit to tunnel.

IMG#: 0149-13
Head capsule recovered from the tunnel in the previous photos (0149-10 through 0149-12), hypothesized (but not confirmed) to belong to an early instar of *Mompha luciferella*. Older larvae of *M. luciferella* finish their work in deeper tissues of the stem.

IMG#: 0149-14
Another example of a shallow tunnel in the middle to upper reaches of a stem of the host plant, hypothesized to be the work of *Mompha luciferella*. The author's notes read: "This was maybe 6/10ths of the way up the stem. The shallow tunnel continued maybe 35-40mm further down the stem, with darkish brown frass scattered throughout, then seemed to end in a slightly enlarged chamber-like spot; I didn't find a larva there and wasn't able to follow the tunnel further." (Photo date: August 21, 2022)

IMG#: 0149-15
The tunnel from the previous photo (0149-14), backlit, showing frass accumulation inside.

Specimen data for images

Coll. 10/26/20, photographed same day (01-03); coll. 04/21/21, adult em. 05/12/21, photos of adult and exuviae on 05/12/21-05/14/21 (04-09); coll. 08/02/22, photographed same day (10-13); coll. 08/21/22, photographed same day (14-15).

References

[none]

Page created 11/23/23. Last update: 11/19/24