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Raspberry beetle


by Pippa Greenwood

This has definitely been a year of grotty raspberries. The raspberry beetle, Byturus tormentosus, is to blame. Affected berries have telltale dry, grey-brown patches around the top edges.


Pippa GreenwoodThis has definitely been a year of grotty raspberries. The raspberry beetle, Byturus tormentosus, is to blame. Affected berries have telltale dry, grey-brown patches around the top edges.

I’ve never known anything like it. I was at a horticultural show recently, and 80% of the questions people asked me were about their poorly raspberries. I only grow autumn-fruiting varieties at home, which normally avoid attentions of raspberry beetle, but the early berries have been affected. So I wasn’t too surprised to find that when the kids and I went to a local Pick Your Own farm, we discovered that their summer-fruiting raspberries were also rather iffy.

The creamy white-brown larvae may be anything up to 7 or 8mm long, and although they’re not always easy to spot in the fruit, if you leave the container of picked berries in your kitchen for an hour, you’re likely to see the culprits appear around the edges of the bowl.

Sadly, the recent wet weather seems to have exacerbated the problem, because affected fruits go mouldy very quickly if it rains.

Whether you eat affected fruits or not is up to you. But it’s important to remove infested fruits immediately, to reduce the likelihood of infestation next year. Being an organic gardener, I don’t use pesticides, but carefully timed applications of pyrethrum will control the infestation. If you do decide to spray, follow the label instructions carefully. The chemical needs to be applied at different times, depending on the crop that’s being attacked – it's not just raspberries which are affected, but also blackberries , logan berries and other hybrid berries  that are at risk. But whatever the crop, only spray at dusk to minimize the risk of damage to bees and other beneficial and pollinating insects.



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Gardeners' World Web User 01/08/2009 at 17:08

Should I be feeling smug that we had a bumper raspberry harvest this year? According to one of our allotment inspectors it was 2008 when south London raspberries failed. No sign of Byturus though.

Gardeners' World Web User 02/08/2009 at 17:50

We too have had record numbers of raspberries, in SE London. In fact all our fruit is unexpectedly looking good this year. Our neighbour even had peaches for the first time

Gardeners' World Web User 06/08/2009 at 14:23

I am growing tomato, variety Garden Pearl( a compact bushy variety)in containers on a sunny patio. It`s growing well & setting lots of fruit, which are swelling nicely. They seem to be trying to turn red. Do i just have to be patient, or is there anything else i can do other than a sun dance!?! I feed them at least once a week and water well daily. Regards Carole

Gardeners' World Web User 12/08/2009 at 20:46

Keep to the sun dance!!! It will happen, but should the fruits be spoiled by excessive wet weather, pick them off as later fruits will (weather permitting!) be fine!

Gardeners' World Web User 25/08/2009 at 17:52

Re: raspberry beetle. On my allotment in Norfolk I lost 90% of my loganberries and in the end just gave up picking them,I had used liquid derris in previous year which gave nearly 100% effective. Marshalls advised the use of the contact inscticide Py. During July most of my early blackberries were devoured by flying insects - flies, wasps, hovers,et al.

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