Unless you were out and about on the Green midweek during the day, you wouldn't have been aware of the insect inspectors. They came from the Forestry Commission wearing hi-vis jackets and trained their binoculars on the Green’s one and only oak tree. They surveyed. They discussed. And after a few minutes, the inspection was over: the inspectors had found nothing untoward and they packed up and left. Phew!
They were looking for the nest of a very unwelcome insect, the oak processionary moth, so-called because the caterpillars leave the nest to feed in single file, head to tail, in large processions and then return home in the same style. The moth’s nest looks like “a grey wart on the side 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,” according to forester Simon Levy, quoted in the national press last year. The tree was clear.
The moths are natives of central and southern Europe, but their range is expanding, to northern France, the Netherlands, even southern Sweden, possibly because of climate change. It is believed that eggs first arrived in the UK on oak imported from mainland Europe, and the dastardly larvae were first detected in Ealing and Richmond in 2006. Since then, there have been infestations in south London, west London and Berkshire. Two years ago, the Forestry Commission announced that helicopters would be deployed to "blanket spray woodland" where the caterpillars posed a health threat (Daily Telegraph, May 2013). The Forestry Commission must have assessed that Fortune Green was a potential infestation zone because it laid traps in the cemetery last summer. Four adult males were caught then, and where there are adults in the summer, there may be nests laid on oaks in the area the following spring. Hence the inspectors’ call.
Luckily, there’s no infestation here this year. We can walk our dogs and sit under our trees safe in the knowledge that we have received an official all clear from the insect inspectors.
- Catherine Allison