Black/grey larvae identification.

davidjspalmer_5UMxYdU

Hello, we keep finding these black- grey larvae in our garden sandpit. 
Any idea what they are? 
Thanks!

Dovefromabove

Hello @davidjspalmer_5UMxYdU and welcome to the forum 😊 

Those look like ‘leatherjackets’ … the larvae of the Cranefly aka Daddy Long Legs. No danger to your children (although I wouldn’t advise eating them) but if they’re also in your lawn they’ll eat the roots of the grass 😧. You can treat the lawn with specific leatherjacket nematodes … now is about the right time of year … which again will be safe for children and pets but will certainly help get rid of the cranefly problem. 

Hope that helps 😊 

davidjspalmer_5UMxYdU

Thank you! I'll look into that treatment. 
I've not seen a lot of crane flies around, and it's a bit of a puzzle as the sandpit has a cover...
We recently put a bark area down for the children and I wondered if that was anything to do with it. 

Dovefromabove

The crane flies will have laid their eggs last autumn … the adults are only around for a short while to mate and reproduce and then die. Some of them don’t even eat. Fascinating lifecycle 
https://insectcop.net/lifespan-life-cycle-of-crane-fly/#:~:text=The entire life cycle of the crane fly,so short-lived that many species don’t%20even%20eat.

davidjspalmer_5UMxYdU

Wow, that is an interesting one. 

Can't have happened here, as the sand has only been there a couple of weeks. I wonder if the sand itself had the eggs in when I bought it? 

Fairygirl

They certainly look like leatherjackets. It's possible they were in the sand, although it seems unusual. They may have been in the bark, rather than the sand. 

If you have an area you can lay them out, the crows/magpies/starlings will take them. 

Dovefromabove

Leatherjackets sometimes wriggle to the surface of the turf during periods of heavy rain, to avoid drowning … they sometimes appear on patios and paths again those times … perhaps they somehow wriggled into the sandpit?