Stem borer (Diptera: Scathophagidae) in Maianthemum [0324]

Order	Diptera
Family	Scathophagidae[M,L,P,A]
Lower taxon	Plethochaeta varicolor Coquillett
No. spp. involved	One confirmed [1-C]
Feeding mode	Stem borer
Host plant	False Solomon's seal / Solomon's plume, Maianthemum sp. (Ruscaceae)

Tunnels in stem of the host, finishing up and pupating in the stem fairly late in the season (one observed individual was still a larva as of October 3, and by October 16 it had finally formed its puparium). Adults were reared in spring 2022 from overwintered puparia. This fly is one of the author's favorite stem-boring insects encountered in the current study. The host is a Maianthemum that has not yet been identified to species, either M. racemosum or M. stellatum. Species-level identification of the fly is courtesy B. Sinclair (pers. comm., via C. Eiseman).

IMG#: 0324-01
Larva in dissected stem. (Photo date: October 4, 2021)

IMG#: 0324-02
Anterior end of larva in dissected stem.

IMG#: 0324-03
Posterior spiracles of larva.

IMG#: 0324-07
Larva's damage to the stem interior.

IMG#: 0324-08
Puparium, formed in the stem. (Photo date: October 17, 2021)

IMG#: 0324-10
Posterior spiracles of puparium, dorsal view.

IMG#: 0324-11
Anterior spiracles of puparium.

IMG#: 0324-12
Anterior spiracle of puparium.

IMG#: 0324-13
Puparium, backlit, revealing pupa developing inside. (Photo date: March 21, 2022)

IMG#: 0324-14
Reared adult. (Photo date: March 13, 2022)

IMG#: 0324-19
Head and thorax of reared adult in dorsal view.

IMG#: 0324-18
Reared adult, lateral. (Photo date: March 27, 2022)

Specimen data for images

Coll. 10/03/21, photos of larva and stem damage on 10/04/21 (01-07), puparium formed by 10/16/21, photos of puparium on 10/17/21 (08-12), photo of maturing pupa in puparium on 03/21/22 (13), adult em. 03/23/22, photo of adult on 03/27/22 (18); coll. 11/05/21, adult em. 03/13/22, photos of adult on 03/13/22 (14-15) and 03/20/22 (16-17, 19).

References

[none]

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