The summer is here, although it is a typical British variable weather one at the moment! However warm and wet conditions often provide ideal conditions for certain pest species.
One insect species that can be a pest is certain types of moth.
Recently there has been an influx of Diamond Back moths, of which the caterpillars can cause serious damage to brassica crops and plants.
The Diamond Back moth
Diamond Back Moth damage
Another new invader is the Box Tree Caterpillar moth, which has ended up in the south east of the U.K. , after originating from South Asia. The larvae/ caterpillars of this species can have a devastating impact on box plants and hedges.
The plant leaves are shredded and box hedges look like they have serious die back, although this must not be confused with box blight, which is a different problem that box plants can experience. Box Tree Caterpillars eventually spin white webs around themselves as they pupate. This can make treating against them even more difficult. If you think you have a case of Box Tree Caterpillars , you can take part in a survey on the RHS website to monitor where they are spreading to in the UK.
Box Tree Caterpillar
Box Tree Moth Trap
To help and monitor and control this pest, it is possible to use a Box Tree Caterpillar Moth trap. This uses a specific pheromone to attract the male box tree moths to drop into a funnel trap, where they are caught and drowned.
This helps to prevent male moths mating , which in turn reduces female egg laying and hence reduce the development of the caterpillars.
If caterpillars do appear on the box, it is possible to treat with a natural pyrethrum spray . This kills on contact but does not persist on the plant to kill other insects and is not absorbed by the plant. Natural pyrethrum is made from chryanth flowers and is a recognised organic insecticide. One such product is Pyrol bug and larvae killer available on the Dragonfli website along with the new Box Tree Caterpillar moth trap.
Lets keep these pests under control.