Burdock Gall Fly Taken at Pow Burn on 24th June 2012 using Panasonic Lumix LX5 in macro mode. Burdock Gall Fly. Species : Order: Family: Local names: Terellia tussilaginis. Diptera. Tephritidae. Larval Food: Adult Food: Length: Habitat: Flies/Found: Feature: The larvae live in the flowerheads of Burdocks, feeding on them and causing galls to form. Burdocks 5 mm. Meadows, gardens and where the host plants grow. June - August. Plant galls are abnormal outgrowths of plant tissues, similar to benign tumors or warts in animals. They can be caused by various parasites, from fungi and bacteria, to insects and mites. Insect galls are the highly distinctive plant structures formed by some herbivorous insects as their own microhabitats. They are plant tissue which is controlled by the insect. Galls act as both the habitat and food source for the maker of the gall. The interior of a gall can contain edible nutritious starch and other tissues. Galls may also provide the insect with physical protection from predators.