陳蕙雅思閱讀短文 - 全英森林受病蟲害侵擾

全英森林現狀堪憂，本島上蘇格蘭、英格蘭、威爾士三個地區沒有一個倖免的，各種病蟲害把森林傷的不輕。

A year after the first case of ash dieback in wild trees in Britain, the disease has now spread across much of England, Wales and Scotland. The public is being asked to be the "eyes and ears" of the countryside amid concern about new global threats that could spell disaster for forests.

In a London park, forester Simon Levey is checking a moth trap strung high in the canopy of an oak tree.

He is searching for signs of the oak processionary moth, which is present in parts of the capital and Berkshire.

When the moth's caterpillars emerge from their nests, they can strip oak trees bare and harm human health.

"What we're looking for in these oak trees we see around us is their nests," says Mr Levey.

"They're like a grey wart on the size of a tree that can range from the size of a golf ball, if not smaller, to things that are almost a couple of foot in size."

It is the moth's caterpillars - with their thousands of tiny hairs - that are the hazard. Touching the caterpillars or their nests can cause skin rashes or, in extreme cases, sore throats, breathing difficulties and eye problems.

In Croydon, inspections are being carried out for the moth around a 2km zone as part of a rigorous programme of control and monitoring. Infected areas are sprayed with a bacteriological agent to destroy nests and caterpillars.

The traps - which contain a sex hormone that attracts male moths - are set outside from July to September, when adult moths are in flight, to see how far they have spread.

"We've actually created a ring of traps for these moths round the infected area just to see if the moths are flying beyond where we would expect them to be," says Mr Levey.