Onion Fly. Community › Community › Garden Problems › Pests › Onion Fly. This topic has 0 replies, 1 voice, and was last updated 12 years, 2 months ago by d003kk. Viewing 1 post (of 1 total) Author Posts 4th June 2014 at 8:22 am #22051 d003kkMember Hi Everyone. Is anybody else suffering with onion fly this year? I have a few plants that wilted due to the disgusting maggots eating the roots. I am digging up the wilted plants and putting them in the bin (not the compost heap) in a bid to prevent further contagion. Next year I intend to net the crop as its most disheartening. Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In