boxwood caterpillar

Although relatively late to Europe (2011-2014) this moth larvae has become a recurring and widely established visitor in England and can cause severe defoliation. It was actually first discovered in 1859 by Francis Walker.

What are the key facts:

  • Common name = Box Tree Caterpillar
  • Scientific name = Cydalima perspectalis
  • They feed on Buxus plants
  • They are most active rom April – October
  • Common symptoms include webbing and eaten foliage


What to look out for:

  • Green-yellow caterpillars with black heads and white stripes along the length of the body– these can grow to up to 4cm in length
  • Pale yellow flattish eggs on the underside of box leaves
  • Adult moths usually have white wings but they can be clear or brown too
  • Webbing if left over eaten leave areas


Silk like webbing is spun across the foliage

UK box tree caterpillar webbing

How to control and prevent

This extract from explains that it’s important not to give up on your plant if it’s been attacked by a boxwood, because it will come back to life if you treat it properly.

“The young caterpillars eat parts of the foliage but it is mainly the older caterpillars that cause a lot of damage. Adult caterpillars can defoliate an entire plant in a short time. Only spider mites remain on the affected plants. Although the plant looks desolate at that moment, the boxwood will sprout fresh green again after 8 weeks, due to its strong recuperation capacity. However, it is important not to let the plant get eaten again.”


Top tips for treating Box Caterpillar

  • Early treatment yields best results
  • Eaten plants will recuperate and do not need to be removed
  • Removing the caterpillars by hand is the best method but there are pheromone traps that can be used
  • Wipe all leave undersides to remove any eggs
  • Insecticides can be very effective but need thorough forceful spraying (and respraying 7-10 days later)to penetrate the webbing one that seems to highly recommended for effectiveness is dipel
  • Plants in flower should not be sprayed due to the risk for pollinating insects
  • Natural enemies in small birds such as blue tits have developed – but this is not a treatment that is likely to be relied upon!

Prevention is often key with this little plague, if you need help in treatment or prevention for your plants, we can assist you, whatever you do don’t leave it to its own devices!

Get in touch and we can help treat this for you.