The pictures below are of the larvae and of the damage that they do. They leave behind a light orange sawdust, and severed rhizomes.
To check your hop:
1 - give the stump a wiggle. If it's loose then you probably have a problem.
2 - Dig around the plant. It won't mind. It knows it's for the greater good. They're really easy to spot, bright white against the soil. They will mostly be within the top inch or two (deeper if you mulched like a good boy/girl).
3 - If you find any, do your best to dig around the whole plant where the soil feels loose and pick them all out. Destroy them by squashing or drowning.
4 - While you're there, pick out anything else that isn't a worm. Leatherjackets (weird fleshy brown tubes, the larvae of Daddy Long Legs), slugs and millipedes (the black ones).
5 - check the soil before you put any back, or better still, replace it with fresh compost.
Do it now while the hop is still feeding on it's rootstock. Don't worry about little white roots.
Fundamental critter rule: If it's slow, it's got to go. If it's fast, ... something something last.
It's April 4th, and most of my hop plants are putting out bull-shoots and several other smaller shoots, so the ones that are struggling are pretty conspicuous in their sluggishness. Check them or you'll get no hops.
|Vine Weevile Larvae. AaaaaarGH!|
If you have them in one pot, you're likely to have them in all. Check! They seem to prefer pots to plants in the ground, so far...