Topic: Southern Green Shield Bug

[Eristic]

I've mentioned before that if not taken seriously, these bests are likely to become a serious pest in the near future. The unseasonably cold summer has hampered their advance but the past few weeks have brought them out of hiding and they are multiplying fast.

The damage at the top of my runner beans has occurred within the past 2-3 weeks and the bugs are hatching out faster than I can squish them.



Closeup of the insects.

[beejay]

We had them last Sep/Oct in the garden & on the allotment but haven'y noticed any this year so far. I did read they could become a serious pest unlike our native shield bugs. They were too late to do much actual damage last year.

[Barnowl]

We had them last year, but have yet to spot any this season......I did get fairly biblical on them last year, which may have helped.

[Lauren S]

Thanks for the warning. If I had seen them I would have mistaken them for a species of ladybird.  ::)

Lauren  :(

[wiltshire lass]

I had them on mine this year.What was worse was they did a lot of damage when i was on holiday.
A friend of mine got rid of most of his by tipping soapy water over the plants.The soap stops the bugs from sticking. :)

[OllieC]

I have a lot of brown shield bugs on my Raspberries but with no obvious damage. Shall grab a piccie when I'm there next. Anyone else noticed this?

[cornykev]

They look like greedy buggers Eristic, looks like the green shield should be STAMPED out.   ;D ;D ;D ;D ;D

[Eristic]

green shield should be STAMPED out

Those were the days.

I don't want to frighten anyone but if we were to have a long hot summer and assume 6 females overwintered, assume 50% of offspring is female, assume 100 eggs, no natural predators and possible 5 generations it looks like this

1st batch = 600
2nd ...... = 30000
3rd ......  = 1500000
4th ......  = 75 million
5th ... You really do not want to know.

These insects may be the cause of many of the outbreaks of blight and would go some way to explain why the blight popped up fast, early, random and in enclosed safe locations such as greenhouses.

[mc55]

I'm confused, I thought shield bugs were goodies  ???

[Robert_Brenchley]

This is an introduced species which is decidedly no goody. Native shield bugs are vegetarian, but don't do any damage. As you see, this one does.

[star]

Groan....... not another introduction.

Do you know why they were introduced?

I do wish people would stop trying to 'help' Mother Nature, SHE DONT NEED IT!

[Robert_Brenchley]

it was probably quite accidental; all i've been able to find out is that it was found in the Greater London area a few years ago.

[Barnowl]

RHS reckon accidental 

[Eristic]

RHS reckon accidental

What would they know?

[OllieC]

Don't you rate the RHS, Eristic?

[Eristic]

Pah! An institution full of Neverdoneits telling Nointentionofdoinits how to do it. Their books are of the highest price and lowest quality on the market, appalling photographs that would be rejected out of hand by any monthly magazine, errors on most pages. The only thing guaranteed to be correct is the spelling.

I wonder how many of their top bods there are running round monitoring the activity of this bug on a daily basis 365 days a year? Half of their accrued knowledge of the bug is probably cribbed from my postings on various forums and my websites.

[OllieC]

Eristic, will you please get off the fence and say what you mean!

[Barnowl]

Last year when I asked what they were no-one knew and I sent a phto to the RHS. This was the reply:

"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. 

This insect should not be confused with the native green shield bug, Palomena prasina, which also occurs in gardens but is generally not regarded as being a problem.  The immature nymphs of the native green shield bug do not have round spots but are pale green with black bars down the central line of the upper surface of the abdomen.  Adult native green shield bugs are pale green but have a distinctive blackish-brown area at the rear end of the body where the wing cases meet."

I thought that was pretty authoratative :)


They do seem a bit keen on the old chemicals though......

[Kea]

Seems it's heading North then as it was in south london now in North london I guess we get them soon.

Yes OllieC I also had a lot of brown shield bugs on my raspberries, they must be eating something else on the raspberries. They don't seem to do any damage themselves.