No guard needed for shield bug

UK GROWERS have little to fear from a new shield bug that has been discovered breeding in the UK, according to a top entomologist.

The green vegetable bugs (Nezara viridula) attack a broad range of crops, from soft fruits to potatoes and beans, damaging fruit, transmitting disease and leaving plants open to attack by other pathogens.

They are a particular problem in the Mediterranean, the Middle East, Australia, North America and Africa, and are found increasingly in imported produce.

New evidence suggests several colonies of the beetle have now been found living and breeding in London, prompting worries they could become resident in the British Isles.

But they are not seen as a great threat to crops grown in the UK, according to Central Science Laboratory entomologist Ray Cannon, who briefs DEFRA Plant Health on pest issues.

“In spite of climate change, it‘s still too cold – we have no firm evidence it has successfully overwintered here.”

He confirmed that climate change and increasing global traffic of produce was bringing about more “incursions” of these sorts of pests.

“But even if they do breed successfully, it is doubtful numbers would build sufficiently to cause any major damage.”

London has a tendency to be a “heat island”, added Dr Cannon, with a noticeably warmer climate to the rest of the UK.

Known as stink bugs in the US, due to the foul-smelling toxic chemicals they secrete, the new beetles have been regular stowaways in imported stocks for over 25 years.

They have a 10-week life cycle – relatively long for this type of pest – and can bring secondary damage from other pests or diseases into affected plants.

The alarm was raised by the Natural History Museum after three colonies of nymphs were brought to the attention of staff that look after the world‘s largest and richest collections of insects.

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