Raspberry Beetle – Not a Six on Saturday

Ok, before we start, I will admit this isn’t a real Six on Saturday… mainly because I have the grand total of three photos, and one topic to type about! But as nobody I’d asked online had come across this before, I’m hoping it’ll make for an interesting read, so welcome to my Not a Six on Saturday!

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…

Signs of Raspberry Beetle

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!):

The Raspberry Beetle grub

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

10 thoughts on “Raspberry Beetle – Not a Six on Saturday”

  1. I’ve seen this kind of damage on wild blackberries here and I’ve also seen similar grubs, ( and possibly eaten a few!) but don’t have any answers I’m afraid.

    1. I didn’t realise these grubs were a problem over your side of the pond as well! I’m hoping that the local badger population might enjoy snacking on them….

  2. Very interesting and educational post. I’ve never seen or heard of this pest here in Georgia, USA. I do spend a lot of effort attracting birds to my garden, by planting fruiting bushes of various kinds including native plants with winter seeds that birds like, and letting the birds freely feed from them (never netting, etc); I also leave wild areas in corners and unclipped hedges wherever possible, for habitat, as well as putting up birdhouses and placing bird feeders and birdbaths. I have read more than once that water is more important than birdfeed for attracting birds, and that birds are especially attracted to dripping or moving water as in a fountain. I also found the following (very similar to what you found) while researching your raspberry beetle online: “After harvest, raking or shallowly cultivating the soil around your raspberry canes can break up pupating larvae in the soil. If you keep chickens, this is a great time to let them in the garden to help destroy the tasty beetles.” Which raised an interesting thought – if you can’t attract wild birds, can you bring in your own as needed?

    1. We get some large birds (mostly crows / ravens) drinking from the water troughs, but they don’t hang around long – I think the neighbourhood cats scare most of them off.
      That’s an interesting thought on chickens though!

  3. Hi, yes mine were exactly the same and I self diagnosed raspberry beetle. I had half stemmed my autumn rasps for an earlier crop and most of the early berries showed signs of raspberry beetles. Current rasps are fine. Thanks for confirming my suspicions. Not sure of way forward. I think i’ll move them and start over with some new canes. Good luck with yours, Anna ( in the UK)

    1. I did consider moving a couple of raspberry plants (I accidentally lifted on while I was weeding, and it came out bare rooted, so I should be able to rinse the roots to make sure there’s no grubs lurking) in a different part of my plot to see if I can trick the raspberry beetle – I’ve got a spare bit of space near my herb patch, so that might be worth a try to see if that soil is unaffected.

      Let me know how yours get on!

  4. Haven’t a clue, but will be checking mine very closely next year. Thanks for this Not Six warning! Hope you get some informative responses to you question.

    1. It’s one of the disadvantages of the raspberries growing semi-wild – I’ve just let them continue growing there for the last 9 years or so… I think the ground is showing signs of getting fed up with those raspberries being there!

  5. My dad grew a long row of raspberries in western Washington state. I saw plenty of raspberries with damage like yours, but assumed it was just something that raspberries did. I wonder how many beetles I ate without knowing it.

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