Box Tree caterpillar

vgardner211219

How does this insect overwinter?  Is removing the damaged foliage also going to remove pupae/eggs and reduce the damage for next year ?

KeenOnGreen

Box is so dense and with tiny leaves that I think you would find it impossible to remove damaged foliage, and all of the eggs.  I have seen people use pheromone traps, and these seem to work, but it's a continual process, not a one-off.  If you want to stop the caterpillar in your garden, be prepared for a lot of time and effort every year from now on.

The moths can fly a reasonable distance, so even if you did manage to get all of last years eggs off your plants, the moths can come in and lay a new batch.  We decided to get rid of our Box.  There are so many great alternatives to Box, and which are not susceptible to any diseases, meaning you can focus on other plants, and enjoying your garden.  Personally we don't see the point in fighting nature, if any plant is heavily/persistently diseased or attacked, we stop growing it.  That probably sounds very negative, but for everything we have lost in the garden (no matter how precious), it has always given us the opportunity to design/plant something new and exciting.

Lizzie27

@ Keenongreen, I think I'm going to do the same next year, having seen signs of caterpillar damage in the autumn. It's a pity as I've got lots of box balls and low box hedging in my largish garden but on the other hand, box is a greedy hungry plant so my other plants might do better without it nearby, I will be able to reduce watering and I won't have to spend hours clipping it several times a year.

vgardner211219

The box I am  working with is in my local Victorian cemetery.  There are a lot of them but the damage is very patchy here and there.  I thought it was worth trying and just see if there is any reduction in the infestation  next year.  Any info about overwintering eggs or pupae and where they are usually found would be appreciated.

KeenOnGreen

@vgardner211219  Here's some information that should answer your question.  Moth and butterfly eggs are minute, and very hard to spot, even on plants with an open habit.  Looking for them in dense Box (which would also be covered in the webbing from the caterpillar's), would be like looking for a needle in a haystack.

Pheromone traps appears to be the only possible solution, with no guarantee that even that is 100% effective.  In our experience the infestations got worse each year, and we see more and more damage in local gardens, as the moth expands in territory in England.

vgardner211219

Thank you for your comments.  The prospect is not too bright for the future!

amancalledgeorge

Worth having a look at the walled garden at RHS Wisley where they have grown alternatives for box which may give you some ideas what to replace it with. 
https://www.rhs.org.uk/gardens/wisley/garden-highlights/the-walled-gardens?compactView=true

KeenOnGreen

Pittorsporums have become our new "Box".  With a wide variety of foliages size and colour, we find they are actually much better, although they won't be hardy in all parts of the country.  Euonymus "Green Spire", is closer to the actual colouring and size of Box.

Allotment Boy

I thought that the moth pupates in the ground under the plants,  but I don't think that changes the advice you have.  I volunteer at Capel manor, they have taken out the worst damaged box there, they are managing the rest with diligent contact spraying.

Rubytoo

I have some box plants that I have been growing from cuttings for a few years now. I never planted them out yet... We found moths last year and had a few pupae in leaf rolls which I snipped off or removed. We only have twenty three potted ones.
But I am thinking of getting rid or composting, which is so sad.

So sorry I think they do not pupate in the ground,, they are on the leaves here.

There are some varieties which I think were mentioned in the RHS mag last month as being new cultivars which are less susceptible but that might have been blight?
Anyone?