have spotted a few shield bugs around, both green and brown.
I know they don't taste nice, as my mog had a chew on a green one and went all dribbly and was galloping about like a maddo.
are they good or bad news for plants? ???
(just googled them and found this page, lots of pics:
http://www.gardensafari.net/english/shieldbugs.htm
and they're also called stink bugs because they emit stuff when touched â€" no wonder my cat was so unimpressed!)
can't find any info on whether or not they're a pest though...
hope not, we've got lots :)
I don't think they are harmful. I usually get them on the washing when I go to get it in.
Ok. I have good news and I have bad news.
The native English green shield bug can be safely ignored and is of no concern to the gardener, however, there is now another one native to Eithiopa called the Southern green shield bug (Nezara viridula) that is likely to become a virulent pest in this country with consequences far greater than that possible from similar numbers of colorado beetles.
Let me have my supper and I will dig out some pictures from my collection. Our allotments had quite a large outbreak of these last year but no one seemed to be interested almost like the authorities did not want them in their statistics.
Ok here's a few images for you. First we have the native English bug with distinctive black wedge at the rear. Whilst I wouldn't go so far as to call it a good guy, it can be ignored as it is normally only present in small numbers.
(http://www.whitewisteria.co.uk/images/companions/Shield_bug.jpg)
The Pest.
This is the pest in breeding colour. normally the adult will be a uniform green colour over the entire body. Body is narrower and more pointed on this species and has prominant spots along both sides. A female can lay several hundred eggs, possibly more than once, and there are 5 generations in a warm summer. That's millions.
(http://www.bluewisteria.co.uk/pest/images/Nezara_viridula_adult.jpg)
The damage is caused by the juveniles which suck sap in the same manner as aphids except these are the size of ladybirds. The photo below shows them clearly eating my runner beans last year. They seem to infest a wide variety of plants but their favourites are beans, potatoes, tomato's, peppers and sweetcorn. The authorities seem to have you believe that there was only 3 sightings of this pest last year but the truth is it was endemic throughout north London, possibly the entire south of England, and the mild winter now means that large breeding colonies could be permanently established in the South of the country. Defra does not care much because they have had nothing to do since they managed to double the price of railway sleepers.
There are no natural predators for the pest in this country and the only defences are vigilance or toxic sprays.
(http://www.david-frary.com/images/Nezara_viridula.jpg)
i've always had the native variety, and they've never done any detectable harm. by all accounts, though, you do need to watch out for the introduced one.
YIKES! My uncle works for DEFRA. What's all this about railway sleepers? My gramps defines my uncles job as this : If they build a supermarket there and a shopping centre here, how many suicides will there be?
thanks for all the info, Eristic.
I'm pretty sure that the ones I've seen are the native English bugs, rather than the immigrant nasties. so far.
will keep my eyes peeled though.
are you supposed to report sightings of them, and if so to DEFRA or someone else?
Quoteare you supposed to report sightings of them, and if so to DEFRA or someone else?
No one wants to know about anything new. If it's not on the ancient Ministry of Agriculture's list of pest threats then it is not a threat. Sightings of Colorado beetles must be notified to the authorities, and maybe with some justification, but anything new is just a curiosity and there is no plan to deal with curiosities.
Defra exists to destroy things, preferably by fire. A few cows got sick a few years back but rather than give them a 10p injection that would cure them, every cow for miles around had to be killed. Before long there is a monumental stink so all the railway sleepers in the country are gathered up into huge piles to make glorious bonfires.
Most of you are too young to remember the glorious stands of elm trees once present in this country. Unfortunately they had a pest called the elm beetle which could destroy a tree over time. The Ministry of Agriculture had a brainwave, cut down every last tree they could find and had some super bonfires. No elm trees - no elm beetles. Problem solved.
Anyway, back to the shield bugs. The authorities are probably correct when they say one really cold winter will wipe them out but until then we must keep our eyes open to the potential damage these can do in a hot summer. Look for the nymphs on all the likely food plants and deal with any you find without delay. The use of insecticides has to be your decision alone but manual removal may prove difficult when colonies expand.
slightly off topic but the council in all their wisdom have recently felled quite a few big old trees on local heathland for 'Health and Safety reasons': in case the branches fall on the public and they sue. :o ::)
This is what Mr Halstead of the Natural Histroy Museum wrote last year:
'The insects that you have found on your runner beans are immature nymphs of an insect commonly known as the southern green shield bug, Nezara viridula. The adult insect is about 12mm in length, pale green in colour and has a shield-like shape when viewed from above. The immature nymphs have a more rounded shape and vary in colour as they develop but have a series of white, pale yellow or pinkish spots that can cause them to be misidentified as ladybirds. The southern green shield bug is a European insect that became established in Britain as a breeding insect during 2003. It has now become established in several places, particularly in west London.
This insect feeds on a wide range of plants that include vegetables, soft fruits and ornamental plants. It has the potential to be a pest species as it feeds by sucking sap and heavy infestations can affect the growth of plants. However, it does not seem to become abundant until very late in the growing season in Britain and this limits its ability to cause problems. If we continue to have mild winters and hot summers the southern green shield bug may become more abundant earlier in the summer and then it may cause more harm. If it is necessary to take control measures against this insect, you could spray the affected plants with a bifenthrin-based insecticide, such as Scotts Bug Clear, Sprayday Greenfly Killer Plus or Doff All In One Garden Pest Killer.
Ours arrived too late to do any real damage, but it does look as if there is a (admittedly non-eco) solution.
Ha. That is his reply to my sighting via one of my colleagues.
Quote from: norfolklass on May 18, 2007, 12:40:49
slightly off topic but the council in all their wisdom have recently felled quite a few big old trees on local heathland for 'Health and Safety reasons': in case the branches fall on the public and they sue. :o ::)
Sorry for the late reply, but just going through posts I hadn't read before!
You could try getting a tree preservation order put on old trees - not quite sure how it all works, but it means that they would basically become like listed buildings and the tree would have to be made safe and not just chopped down. Darned councils seem to think they can get away with anything! >:(