In which months are the pests the most virulent?
Anton
We've had the ALM since 2014. for us the spring offensive happens around May 1st but unfortunately I've not yet been able to pinpoint the Autumn session. Internet reports say otherwise but we've found the spring flight to be worse than the autumn one. Certainly the first three years were the worst but it never goes away. Even though we now grow alliums under Enviromesh ultra-fine the fly still manages to get through and attack some bulbs.
Re Leeks being trouble free HH, we also get leek moth which I believe spread North as the climate warmed. Leek moth and ALM are supposed to fly at different times but one year our leeks were riddled with ally miner maggots and contained adult leek moths at the same time.
As mentioned above it is possible to watch as the alm grubs track down through the leek and cut it off at ground level just before they get there. The leek will re-grow but it's a gamble as to whether the adult has finished laying her eggs.
Onions, leeks and shallots etc can be completely destroyed by alm, garlic and elephant garlic survive as the grubs only attack the material that will become the paper. Not very nice though to have lots of brown pupae dropping out on the chopping board as you're preparing food to eat
