Chirosia grossicaudaChirosia grossicauda is a species of fly found in Europe. The larvae mine the lower rachis of bracken causing a swelling, known as a gall.LifecycleA white maggot mines the central vein of the pinnule causing the tip to roll downwards. The larva probably pupate in the gall, but are likely to fall out when the fronds wither and fall to the ground, pupating in the leaf litter.ParasitesLarva of Trybliographa ciliaris are endoparasitoid of the larvae of Chirosia grossicauda.DistributionIn Europe the fly is found from Ireland to Russia and from the Iberian Peninsula to Scandinavia. It has also been recorded in South Africa.