Garden pest, Hemerocallis gall midge
Day lilies – Hemerocallis species and cultivars have a parasitic pest called the Gall midge Contarinia quinquenotata
It’s been gradually spreading through the UK since 1989.
There is no control for the pest other than picking off the infected flower buds and destroying them.
Don’t put them in the compost bin as they will pupate and emerge next year.
Burning the buds is the sure way of destroying these maggots.
The adult fly is tiny and lays hundreds of eggs in the developing flower buds. The white maggots grow to about 2-3mm. When ready to pupate the larvae crawl out of the flower bud and fall to the ground where they bury themselves in the soil, pupate, then emerge as adults flies the following year.
Photography By Neil Bromhall Complete Gardens Advice CD-ROM Ltd