Box tree caterpillars

An invasion of caterpillars has been on the march across my local town traveling from garden to garden and leaving all the box hedges stripped of leaves in their wake. Including my beloved box hedge.

Box tree caterpillars are the larvae of the box tree moth (Cydalima perspectalis) and have become a pest on Box (Buxus) plants since they became established in the UK  in 2007. They are now an invasive species and have become a significant pest in gardens and the landscape.

When young, box tree caterpillars are yellow with black heads, but as they mature, they become green with black and white stripes along their bodies. They can grow up to 4 centimetres in length.  The caterpillars feed voraciously on boxwood leaves, often causing extensive damage. They prefer to feed on the younger, tender leaves of the plant leading to defoliation of boxwood plants, weakening them and making them susceptible to other diseases and pests. Severe infestations can even kill the plants.

In an effort to save my box hedge, I resorted to physically removing the caterpillars from my box plants, spending hours hand picking thousands of caterpillars off the hedge. After several days the numbers of caterpillars had not decreased, and I noticed a trail of caterpillars along the path from neighbouring gardens.

The best method of control for these caterpillars is a biological control Bacillus thuringiensis: A natural product which is not harmful to humans or wildlife. The product is sprayed onto the plants several times a year (currently only available for professional use). Another method of biological control is using pheromone traps to catch the male moths which prevents breeding breaking the lifecycle. The traps should be set out from April to October and the lures in the traps should be changed about every six weeks.

If you would like to find out more about controlling pests in your property or business!  Contact: EcoTrap Services call 07852 485053  emails: nigel@ecotrapservices.com