The Forestry Commission is appealing to walkers and ramblers who are out and about in woodlands this summer to look out for pine-tree lappet moths and let it know if they see any.
A population of the species, which could potentially cause serious damage if numbers increase, has been found breeding in pinewoods west of Inverness, including the Commission’s Boblainy Forest. Although occasional individuals have turned up in southern England, pine-tree lappets have never previously been found breeding in Britain, so the species might be a recent arrival or a previously undiscovered resident.
The pine-tree lappet (Dendrolimus pini) is a native of continental Europe, Russia and Asia, where the caterpillars feed mostly on Scots pine needles. The Forestry Commission is concerned that it could become a pest in this country. Its populations can increase significantly from time to time in parts of its range in Europe, leaving large areas of pine woodland stripped of foliage. Many trees die during severe outbreaks because the defoliation makes them susceptible to diseases, bark beetles and wood-boring insects.
Roddie Burgess, head of the Commission’s Plant Health Service, explained, “We are continuing research to try to determine the likelihood of pine-tree lappet being a previously unknown native species or a recent arrival in Scotland and, more importantly, to assess whether it poses a serious risk to Scotland’s pine and spruce forests.
“If the evidence points to the balance of probability being that it does pose a risk, we will look at the best way of taking early action to prevent it spreading further afield and potentially causing serious damage to our woodland environment and forest industries.
“Meanwhile, we are appealing to walkers and ramblers, many of whom are keen observers of wildlife, to keep an eye out for them this summer and report any sightings to us. This information will help us to keep track of their geographical spread and inform any decisions we might need to take.”
Mr Burgess added that it would be very helpful to the Commission to also receive digital photographs of any specimens seen, and any captured specimens if possible, for expert confirmation of their identity.
Reports of sightings, and any photographs, should be accompanied by as precise as possible a description of the spot where they were sighted or captured – preferably an Ordnance Survey grid reference.
Anyone who has captured a specimen should send a photograph and location report in the first instance, and meanwhile place the moth in a secure, rigid plastic container and telephone or email the Forestry Commission contact below for instructions about how and where to send it.
Pine-tree lappet is a large moth: the males have a wingspan of about 60mm (2.5 inches), while the females are larger at 80mm (3.2 inches). Males are a greyish or reddish brown with a white central spot in the middle of the wing and a jagged-edged band across the wing.
They are most likely to be found in or near woodland with a significant proportion of Scots pine trees, but they are also known to feed on other conifers common in Scotland, including Sitka spruce (Picea sitchensis), Douglas fir (Pseudotsuga menziesii), larch (Larix spp.) and lodgepole pine (Pinus contorta).
Anyone who thinks they have seen or captured a pine-tree lappet should contact Forestry Commission Scotland, by email to firstname.lastname@example.org or by telephone to 0131 314 6156.
Further information about the pine-tree lappet, including frequently asked questions, is available by following the “pests and diseases” link on the plant health pages of the Forestry Commission’s website, www.forestry.gov.uk/planthealth, and on the Forest Research website at www.forestresearch.gov.uk/pinetreelappet.