My onion seedlings have been declining over the last several days. At first I thought it was from lack of water since it’s been an abnormally dry spring. Today however I dug a couple up and each is rotting near the crown and there appears to be a larvae in each.
Anybody know what these are and how to slow them down or break their cycle?
Agree that you’ve got onion maggots. They’ve been very destructive here; I stopped growing leeks because of them. Spinosad is a low-toxicity control that helps—though it really needs to be present before the larvae enter the onions; it might save some of your seedlings, though. Probably the surest method where onion maggots are a problem is to grow onions under tight row covers in order to exclude the egg-laying flies.