This is an odd one. A message came in follwed by an email with three photographs [the first 3 – see below – the rest followed shortly after] of what I was told was the tent caterpillar. Which is correct-ish. But not, because the the [eastern] tent caterpillar moth Malacosoma americanum is from [eastern] North America.
That said we weren’t far off the mark. What we have [because I know Donal Conaty lives in Ireland – because his phone number starts with 087 😀 ], is the webber moth. This comes from varying caterpillars one of which is the Malacosoma neustria. Not that far apart 😯 In short what we have are two Donegans – one is simply my long lost brother. Does that make sense….? [the webber moths also include the euproctis chrysorrhoea/ dichomeris marginella/ Yponomeuta sp.]
So these moths [the caterpillars or ugly butterflies of that is…] can affect any tree or shrub, although they have a particular likening for fruit trees, willow, cotoneaster and crataegus to name a few. What they do is very simple to see from Donals images, they cover the entire area of planting with a web.
The problem for any plant affected by a caterpillar is that the leaves are eaten… Loss in leaf means a reduction in photosynthesis and therefore a loss in production or – more important for any plant is it chances of reproduction. In fruit trees in particular and moreso of importance to me and you – it simply means less fruit. And of course it looks ghastly.
The control is quite simple. Remove the web. Remove the caterpillar. Some say careful pruning but I have seen infestations – like a scene from Wuthering Heights – in my time and a garden rake would be more appropriate in some scenes, to start with. My theory for ‘problems’ such as white fly and caterpillars is always wishy washy liquid and a sponge and in this case by hand first. I may go select pruning if its necessary afterwards. In Donals case I know there are over 100 trees affected and spraying with a pyrethrum based biological control may be the choice.
If you are asking for a name of a product – I haven’t a clue what trade names garden centres have them marketed under and they change regularly enough – just bring them this post and tell them I said call me if they [he says jokingly] need any more information 😉