Shooting season hit by plague of beetles

Published on 08/08/2009 19:52

THOUSANDS of acres of grouse moor have been stripped bare by a plague of heather beetles ahead of the Glorious Twelfth.

Some estates in the north of Scotland may now have to cancel planned shoots as a result of being infested with millions of the beetles per square acre earlier this year.

A mild winter followed by a warm and wet early summer has provided ideal conditions for heather beetle larvae to thrive.

The grubs eat the leaves and roots of heather plants, which eventually die from lack of moisture. Land managers have reported outbreaks from upland areas across the country with vast tracts of heather already starting to show the distinctive reddish-brown colour that signals heather beetle presence. By next year, the plants will have turned grey, creating what is called "ghost heather".

Conservation bodies are now calling for the Government to allow grouse moor owners to burn heather earlier in the year so new growth is more able to withstand future beetle attack.

Dr Adam Smith, spokesman for the Game & Wildlife Conservation Trust, said outbreaks had already been reported on around ten moors this year from estates north of Inverness to the Solway Firth.

He said: "They erupt like this for reasons probably related to climate. A warm, damp, settled year preceded by a non-severe winter is good for beetle survival. That's what we have had in 2009.

"Thousands of hectares of heather moorland are affected and it has an impact on grouse numbers. Around 80 per cent of grouse chick diet is heather and they need the juicy, succulent green tips of the plant. If that is being munched away the chicks have to move. When they move and are exposed that is when they get killed."

Climate change, producing mild winters and wetter summers, is making periodic heather beetle outbreaks more likely, experts say. The dark brown beetle hibernates throughout the winter below the surface on the moors and emerges in spring as the temperature rises. It feeds on heather, mates, lays eggs on damp areas of ground and then dies.

By late May, the eggs hatch into grubs, which are greenish yellow with black spots. They invade the heather plants, eating young shoots and damaging stems, with the result that the heather turns a foxy-red colour by July before dying and going completely grey by the following spring. Seedlings and old heather are especially vulnerable to attack, leaving only young, vigorously growing heather capable of surviving.

"You see these fox-red strips and there is this rank and fusty smell," Smith said. "When you walk into this heather these horrible green larvae cling to your boots.

"This is big threat to Scotland's heathery hills. The really worrying thing for grouse moor managers and also producers of heather honey is the weather repeating itself next year. If heather is under stress already for other reasons, the beetle can be the straw that breaks the camel's back."

Davy Thomson, vice-chairman of the Scottish Gamekeepers' Association, said: "The heather beetle is causing real problems this year with millions per square acre in some areas. If grouse hatch chicks in an infested area then they just will not survive because the feeding is just not good enough."

He added that some estates will have to cancel shooting days this season. "The only solution is to burn huge areas of heather but that means they won't fully recover for up to five years."

The Heather Trust, which campaigns to protect the UK's heather moorlands, said the full extent of the outbreak would not be known until spring.

Director Simon Thorp said: "This is a matter of grave concern as, in some cases, entire moors have lost their heather, which has been eaten by the maturing heather beetle larvae during July and August. Instead of flowering at this time of year, the heather plants will appear foxy-red in colour and dry and brittle. If the outbreak has been sufficiently severe, the plant will die completely.

"The knock-on effects of a beetle outbreak can undo many years of moorland management work in a very short space of time. The effects can be hard-hitting for the birds and animals which need heather as part of their diet, such as grouse.

"Those who live and work on the moor will be impacted financially by beetle outbreaks, and people who visit the moors for recreational reasons will certainly be aware of the damage to the landscape."

When the beetles emerge in the spring they swarm and gamekeepers report driving through thick clouds of the insects. But as poor flyers they can be blown long distances on the wind into urban areas. During the last major outbreak in 2004, clouds of the insects descended on Princes Street Gardens in the centre of Edinburgh and were logged in towns and villages across Scotland.