Mention the word “raspberries” and I’m sure most of you are already picturing a big bowl of fresh red fruit, maybe with a healthy helping of clotted cream to go with it? That’s true (and very tasty!), but what if your raspberries are looking more like this…

The first year we noticed this, we wondered what on earth we’d done wrong, thinking it must have been a watering problem, or lack of feed! But no, that kind of nasty dried-up edge is a classic sign of Raspberry Beetle (which incidentally can also affect blackberries, although thankfully they don’t seem to have discovered my blackberry bush).

The beetles lay eggs on the raspberry flowers from May to mid July, but it’s the larvae  / grubs that do the damage – they feast on the fruit (causing that dried up look), moving into the middle of the fruit, before dropping into the soil when they’ve eaten enough. 
They then spend the winter in the soil before starting the whole cycle again in the spring. 

Because of the seasons the grubs are active, they mainly cause a problem for summer raspberries… mine are autumn raspberries, so only the first month of crops are affected – once we get to the second week or so in August, the problem stops until next year.

It’s surprisingly challenging to get a photo of a Raspberry Beetle grub, but I did find one that was co-operative (well, as co-operative as a pest can be!):

I’ve not yet found a way of solving this problem… I read some things which mentioned chemicals (I try to stick to organic methods, so chemicals aren’t an option); and somewhere else had suggested “loosening the soil in the autumn so the birds can eat the overwintering larvae” – that would work if we actually had birds visiting the allotment, as the deer and badgers don’t seem interested in eating those grubs!

This year we’ve tried to remove any raspberries which were affected, and those berries have gone in the garden waste bin – I don’t want to risk composting those berries in case the grubs survive (I had mint growing in my compost bin after all, so I know it’s probably not quite hot enough in there to kill everything off) and just cause more of a problem next year!

Have you ever encountered Raspberry Beetle? And if you have, how did you manage to resolve it / work around it?

Don’t forget to check out the Propagator’s Six on Saturday  and read through the comments section for more blogs to check out!

Want to read more (really?) – check out the RHS page for a bit more info on those pesky Raspberry Beetles