Can anyone tell me about eelworm?

At the lottie today someone told me that her onions had eelworm and that it was likely that everyone would have it.

I did notice when I was weeding the onions that the leaves were all sort of twisted around but didn't think much to it.  They are fine now.

The onions are planted in alternate rows with the carrots to keep the carrot fly away.

Does anyone know anything about eelworm - will it affect the onions, will it affect the carrots and will it affect the area that it is in?

The first thing to do is to be certain that your neighbour is actually talking about onion eelworm and not onion fly or leek moth. The difference is easy. Eelworm are not visible to the naked eye, the others have maggots/caterpillars that are big enough to see easily.

I do not know much about onion eelworm but from a quick google it would appear that you have a nasty problem. Wide rotations or ceasing growing onions, leeks or shallots are the only way to reduce infections

A gap of at least 3 years is needed to reduce it. The reccommended gap for onion white rot is six years so is should fit in with normal rotations.

It can live in the roots of various crops such as beans and carrots which can act as a carrier but are not usually affected. So much for the rotation idea?

It can survive in dried material. That means that you should not put any infected onions or onion waste on your compost heap and not leave it on your plot or dig any in. It must also mean that onion sets could be a source of infection. ( Somewhere in my mind flower bulbs get a hot water dip for eelworm which may also be the case with onion sets - does anyone know about this?)

Thanks for that.     

Sounds like a real pain.