Onion Maggot (Delia platura), also known as seed corn maggot, is an agricultural pest that damages seeds and seedlings in a wide range of crops including corn, beans, onions, garlic, brassicas, potatoes and spinach.
Reports of damage by this pest are usually following cool wet spring conditions. This fact sheet provides practical advice on the damage caused by Onion Maggot, its life cycle, and the cultural, biological and chemical control options. There are also some tips for great further reading if you want to know more.