I got asparagus beetles a couple of years ago. I had topped the beds with leaves in Nov or Dec when I cut them back. We've been in a drought, so I think that's why the leaves didn't break down well and gave the little buggers a nice place to over winter!

The last couple of years I've pulled everything away from the beds and sprayed with sevin (I know, I know!) Well before the gus was due to come up. It seems to be working. Only got a few S shaped gus this year. Nancy

Spears will also contort if slugs have chewed on the stems at soil level before they emerge.

Hmmm... digdirt2 very informative website.

nancyjane_gardener I had beetles the first two years then mulched heavily with wood chips and straw. Last year almost ZERO beetles???

Floral_UK I do have slugs.

I'm a " beyond organic" OCD gardener so most commercial pesticides are verboten. My homemade goto pesticide is a 10% solution of household ammonia which is straight nitrogen. It is a contact killer with no residual effect except adding nitrogen to my soil. I've never seen a sprayed bug walk away from it.

im also experimenting with homeopathic garden controls. Trying helix tosta for slugs now seems to have been successful in a small trial last year

I will take my trusty magnifying glass into the garden later today and see what I see. Will keep you informed.

Thank you all for your precious time.

Asparagus beetles can decimate a new planting of Asparagus if allowed to get out of control but usually a mature patch can withstand them without too much damage unless the population is very high.

I have been had picking both the adults and now the larvae at least a couple times a week since April. The adults can be difficult to catch between your fingers so best to just flick them off the ferns into a soap water solution (beware they can fly!). The larvae are little grey baby slug like looking things about 1/8" - 1/4" long and several can quickly defoliate a fern. They are easy to just squish between your fingers but you will end up with red fingers after squishing several!

While handpicking I have seen ants harvesting gus beetle eggs off of the spears and I've also seen wasps land on and carry off the larvae. As Dave's linked website mentioned there are predatory wasps that will lay their eggs on the larvae but I've never noticed any.

Well here's what I found. Looks like a slug chewed about one third through the stem. This is war. LoneJack, I put the ammonia solution in a spray bottle and that works well.

Thanks again everyone.