The box tree caterpillars of the Pyralid moth Cydalima perspectalis featured in a latest sighting earlier in the year from outside Paris, France (French caterpillar pest) are now reported to be breeding in many gardens in the south east.
The caterpillars may either have been the offspring of moths that have flown across the channel from Europe or possibly hatched from eggs imported on plants. Whether they can form resident populations and survive the Uk winters remains to be seen.
Control of Box tree caterpillars
While these caterpillars undoubtedly defoliate box trees, bushes and hedges and control is necessary, it is hoped that some common sense prevails when it comes to using pesticides to control them.
The use of pesticides in gardens is a last resort as many indiscriminately wipe out all insects, both good and bad, upsetting the balance of nature, have a huge impact on those animals higher up the food chain and sometimes cause unpredictable consequences to the ecosystem.
More environmentally friendly methods of controlling the spread of box tree caterpillars are the use of pheromone traps (which I understand are available) to lure the adult moths and finding the caterpillars early and picking them off. Biological control using nemotodes or ‘organic’ pesticides may also be worth considering.