[Lardman]

I picked / squished and sprayed last year, but they're back in force this year  many of the fern tops are now stripped completely.  This years crop was lower than last with 4-5 spears per plant max and most of those either thin or malformed.

Is control a realistic option? anyone else having/had the same problems - If it's going to be a slow 3-4 season demise I might as well dig the bed up now. 

[ghost61]

We are in the hunt for these as well. Apparently you can use pyrethrum if your not organic, but we end up squishing as many beetles and larva as possible. Our bed is new so we are keeping a close eye on these beasts!

[New shoot]

I use a pyrethrum based spray and it does knock them down, but you have to spray regularly.  I had loads of the little beasties earlier on in the season, but not seen many about lately.  Hopefully I got to them before they laid eggs and I'm benefiting from that now.

Asparagus does like a good soil so thin spears may be due to that.  Mine get a heavy mulch each winter of compost and/or manure.  Malformed ones are often where they have been slug nibbled on one side, just as they are emerging.

[Sparkyrog]

A seaweed mulch helps asparagus if you can't manage that dress lightly with salt 

[Lardman]

The bed was mulched with chicken manure compost in spring, I can't imagine it's a lack of food.

I've been spraying Bayers greenfly + but I swear they've been taking a bath in it.