A member of the
Scathophagidae family (dung flies)
(Photo by Luc Viatour, Wikimedia
First documented by Malloch in 1924, the bud fly
(Neoorthacheta dissimilis) is a seldom-discussed pest that can wreck havoc in
the iris garden. A member of the Scathophagidae family (often referred to as
dung flies), this pest spends its larval stage as a leaf miner and stem
borer. Siberian irises seem to be the food of choice, but bud fly larvae have
been reported on all types of irises, including Louisiana and bearded.
Typically, this small white maggot (a small pale caterpillar in appearance)
bores in the side of an immature iris bud to eat the pollen, destroying the
standards and style arms in the process. Affected flowers may open with webs
or distorted and eaten petals.
(Photo by Nikita Vikhrev, Diptera.info)
Prevention: As with most pests and
diseases, the best preventive measure against bud flies is keeping a clean
garden. Adult flies lay their eggs in the garden litter. Use of a systemic
insecticide before buds have formed can also help curb damage.
Treatment: When you spot a bud with
a bore hole or a disfigured blossom, remove it immediately from the garden.
If there is no exit hole on the removed stem, then check for the maggot by
dissecting the bud or blossom. Once located, kill the maggot so that it
cannot reach adulthood and lay more eggs. A treatment of systemic insecticide
may also be employed to minimize future infestations.
NOTE: If you have a photo of the bud
fly in its larval stage that you would be willing to share with others on
this website, please let me know! Thanks :=)