HELP !! asparagus in its third year but infested with asparagus beetle. have read about rotenene, have any of you used this or do you think squashing the grubs and beetles and removing all foliage will suffice.
Its been illegal since Oct last year to use anything that contains rotenone.
Squashing, however, is both legal and effective! ;)
Put an old white sheet, or some newspaper on the ground before you start trying to squish asparagus beetle, as they tend to drop off to the ground as soon as you get near them. Also rub off the eggs, which are like little flecks of dust usually along the stem near the base, also look out for the grubs, which look a bit like moist bird droppings. I wouldn't get rid of the foliage during the growing season, it may weaken your plants. Someone, I think it was Bob flowerdew said that you should cut the stems down in autumn but leave a stub, then when it gets very cold and they try to overwinter in the woody stub, then pull it out and destroy it, this will help reduce numbers. I do this, I think it helps, but they seem to find their way back in the summer because others nearby don't bother. I do notice that mine get attacked later than other folks.
thanks for replies. i've kept squashing the grubs and beetles and the ferns are recovering. i shall try the bob flowerdew idea, it makes sense. saw a parasitic wasp attacking the grubs, so was wondering if more umbellifer flowers would attract predators to the pest. i am going to try a garlic spray and see what happens!
One word - Provado
Works a treat :)
Asparagus and Lily bettle are pretty much the only thing I'll use insecticides against.