What's eating my french bean seedlings?

Not too easy to tell, but it could be hoverfly larva (goodie).

 

Me neither. But if there are slug or snail trails as well, then it’s either them, or them + the caterpillar. If you only found one caterpillar, then that makes it less likely, I would have thought.

 

Thanks. It was tiny. But I thought my greenhouse was a safe place for seedlings, now I'm in despair. How did the snails get in the greenhouse, could snail eggs have been in the compost? (It was top quality from a reputable firm) & why can't I see them when I go out at night with my torch? But thanks, these are rhetorical questions!

 

THanks! It was tiny.

 

It’s unlikely that it’s the compost. Slugs and snails can get in anywhere if they want to. Don’t despair! I find the best defence is to keep tiny seedlings out of their way, because they love fresh new shoots. I plant into seed trays and modules as much as I can, and then plant them out when they are a little bigger. Even quite small plants are much less vulnerable to slugs. I keep the seed trays in the house until the seeds germinate, as much for the more even temperatures as for the slugs. I keep my polytunnel as dry as possible because slugs hate the dry, and won’t be tempted to come in and wander about. I water early in the day, so it has plenty of time to dry out by night time. Some seed isn’t practical for sowing indoors, and for those, I put down organic slug pellets, covered by netting because birds love them, especially blackbirds.