Colorado Beetle

[Nickd]

Dos anyone have any cunning ideas about how to combat these critters without resorting to chemicals?

We've planted loads of potato plants but have now been warned that this beetle might well spoil the lot. One of our neighbours suffered this last year and now we're worried..

Any advice welcomed!

Nick

[Alexis]

Pick them off and drown them in a crème fraîche pot by trapping them in the water by another pot.  You have to be really keen and organic to do this several times a day though and if you have hundreds of plants....!!

My neighbour has already sprayed his crop three times....

Growing earlies is a good idea (mine)  Then you can harvest the crop before CB becomes serious.  They will then go onto your aubergines and tomatoes.

No veg this year.  New fosse septic been put in.  HURRAH!

[Will]

As Alexis says, you have to be really keen and have no better way of spending many, many hours than picking off small bright red grubs from potato plants.

I know it's not the answer you wanted, but if you do decide enough is enough then sprays are widely used and widely available in France - doryphore (the French for Colorado beetle) is the word to look for. I'm told, by a very reliable French source, that the stuff is also good for getting rid of wasp and hornet nests, but for these it must, for some reason, be applied during the hours of darkness.

[Ian Hoare<br>All the best<br>Ian<br>La Souvigne Corrèze<br>http:www.souvigne.com]

Hi Nick,

There's chemicals and chemicals. water is dangerous stuff, you know, inhaling it can kill you.

Seriously, what we do (we've only got about 6 rows of 10m of potatoes), is to go out as soon as the sun gets hot and remove them physically. The first year we grew potatoes were were horrified to get 50 or 100 in a day, After 10 years or so, we're down to manageable numbers, perhaps 10 a day at worst. We also go over again in mid afternoon. It help to understand their life cycle. They over winter as chrysalids, and when the days warm up, hatch and climb onto the plant to look for a mate. If you get them then, you'll have no probs.

If you miss them and they mate, they lay eggs (the ladies do that!) on the under surface of lower leaves and you can sometimes go through carefully and squash them. I prefer to wait till the grubs first hatch and then spray with the entirely innocuous pyrethrum spray. This kills them on contact, and has no persistence whatseover. (I think it's a permitted spray, along with Derris by the organic movement, though don't quote me on that - in any case it's utterly harmless to us).

If you don't get them all, they grubs eat voraciously and quickly pupate and a second generation of the beetles appear, which is why they can be so damaging. I strongly recommend making a lot of effort to get them as soon as they appear (That was the last fortnight or so, here in the Correze). They are only really bad for the crop if you don't do anything about them. What I do to get them, is to cup my hand under the leaf on which they're sitting and make a pass at the beetle with the other hand to knock it off, what usually happens is that the beetle curls up its legs and rolls off the leaf "to fall to the ground". Teehee, your hand is there to catch them. I then go on to the next plant and so on. They tend to stay put in your hand. When you've gone through the lots or got a handful, put them on a flat stone and crunch them with your shoe. Most satisfying.

[Nickd]

Hi everyone,

thank you for the useful advice. I have yoghurt pots ready and will add beetle hunting to my repetoire along with nightly slug hunts, weed patrol and tick removal from the cats. Oh the joys of rural France! Just one more question if I may, I now know what the larval and adult stages of the beetle look like, thanks to the internet, but what size are they? ie do I need my specs or not?

Many thanks,

Mrs Nickd

[Jo53]

Apparently they overwinter in the soil, which is why you shouldn't plant spuds in the same place two years running. I bought my seed potatoes in Gamme Vert and they were giving away packets of seeds for a plant that allegedly gets rid of the beetles - can't remember what it was called but you could make enquiries at a garden centre. Didn't use it myself as not much of a beetle problem here

Jo