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Shieldbugs


by Richard Jones

I love this clunky green beast, with its clockwork waddle and slight marzipan scent.


Palomena prasina, taken by Richard Jones in his garden.A few years ago I got a terrible swingeing letter from a gardener complaining at my lack of concern over the damage caused by Palomena prasina, the common green shieldbug. I love this clunky green beast, with its clockwork waddle and marzipan scent.

I had quite happily (and rather pompously I’m sorry to say) stated that these lovely insects were never a problem in the garden, because, although they are sap suckers, they prefer wild flowers to cultivated plants. Boy did I get that wrong. I was given a whole list of the beans, courgettes, pumpkins and other crops that they had destroyed in her garden. Oops.

I have to be slightly more circumspect with my comments these days. But when, during that lovely warm sunny burst on Monday afternoon, I found another green shieldbug crawling over the ivy, I felt I could be brazen again.

This is Piezoderus lituratus. It’s slightly narrower and more elegant than Palomena, and has a delicate yellow stripe down each side of its shiny body. Those emerging from hibernation now are mostly green, but the summer form has vague reddish brown patches across its back. It too has a slight smell of mouldy almonds, especially if picked up; these are the bitter-tasting cyanide compounds used by shieldbugs to deter predators.

Piezodorous lituratus, taken by Richard Jones in his garden.Its English name is the gorse shieldbug, and far from attacking garden plants, it focuses its attention on gorse. As far as I know there is no gorse anywhere in gardens hereabouts, but there's a small broom at the front of our house. It will also feed on other woody Fabaceae.

If there are any laburnum growers out there who have suffered severe depredations from this insect, please be gentle with me.



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Talkback: Shieldbugs
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Gardeners' World Web User 04/03/2009 at 21:28

i was watching a documentary the other day about these beautiful native bugs but isnt there a foreign type that climatising in england and inter mating with the native and im sure the foreign one isnt to friendly to plants.

Gardeners' World Web User 05/03/2009 at 16:46

yes I read about that too. I think it's brown in colour.

Gardeners' World Web User 05/03/2009 at 18:44

I too have no problem with shield bugs,I think they are really interesting,it's vine weevils I HATE.Death to them all.

Gardeners' World Web User 05/03/2009 at 20:27

Reply to Michael and Robin. The southern green shieldbug, Nezara viridula, arrived in Britain a few years ago and is obviously well established in the London area. It is similar to Palomena, but the nymphs are beautifully marked with red and white spots. There are some nice pictures here: http://www.britishbugs.org.uk/heteroptera/Pentatomidae/nezara_viridula.html which, incidentally is a very good website for looking up garden bugs. This is a totally different bug species from Palomena so will not interbreed, and will probably not even compete. It too sucks sap from a wide variety of plants (wild and cultivated). There is a possibility that if it spreads widely it might become more of a nuisance than Palomena because it has left its predators and parasitoids behind in southern Europe so populations here increase unchecked. But like all things in the garden, it is not a pest unless it reaches pest proportions.

Gardeners' World Web User 05/03/2009 at 20:36

thank you very much richard for setting me straight

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