BOX TREE MOTH: SEEK AND DESTROY…
Here’s a moth species new to me, that I couldn’t locate on any UK Moth ID site. Then I found out why. The Box Tree Moth Cydalima perspectalis is native to East Asia. It’s an introduced species to Europe, first recorded as recently as 2006 in Germany; 2008 in UK; and nearly everywhere else since. It thrives on Box Buxus colchica, and to an extent the species may have spread with exports of the bush. And it’s plainly a busy reproducer… and now it’s here, it’s probably a stayer.
A few days ago we had one in the kitchen (bonus points for recognising the cookery book it chose to land on). I took some quick photos for ID, failed to find a match online, and resorted to the excellent Moths UK FB page, where mothmaticians quickly respond to images uploaded for ID. I later found out that one of our sons has had two infestations this summer, resulting in total loss of two small rows of box.
KNOW THY ENEMY
The moth lays its eggs on the undersides of Box leaves. The caterpillars feed so rapaciously on the leaves and shoots that they may simply destroy the entire plant. And there are two or three generations gorging each season. Furthermore, there are no natural predators (such as the Asian wasps that target the larvae in their native lands). Maybe in time that will change, with birds and other predator species learning a taste for the things.
There’s also a quite different brown morph / colour variant of the Box Tree Moth to contend with, which I imagine is just as effective in destroying the host plant.
There are apparently various methods of dealing with the problem, mainly involving chemicals, bacteria, nematodes, and pheremone traps. All seem to require intensive repeat applications. Some of these solutions may presumably have an adverse effect on other wildlife.
As far as ‘mistake’ species are concerned, the ones that have accidentally (or through escape or deliberate release) colonised places far from where they belong, I reckon a case-by-case approach is needed. Harmless to humans, other life-forms, ecology and the environment? Bring them on. Harmful in any of those respects, parasitic, fast-spreading, predator-proof, potentially ineradicable? Expunge them ruthlessly.
I take one of these views about the Box Tree Moth. Look out for the eggs, the caterpillars, the imagos. Report them. Or DIY. A box bush might be a good place to start.
Top 3 photos from the kitchen; the others thanks to Wiki. There’s a mass of stuff on these critters and their little ways online if you want to find out more. Not trying to be controversial here, btw, but I’d be surprised if you can’t name half a dozen species of animal, bird and plant that are invasive to the UK / Europe, damaging to the new host territory – and would be best eradicated.
We were sitting having a picnic on the low wall surrounding a small hilltop church in the eastern Pyrenees, when I caught sight of this wonderful creature. A marital ‘no computer’ pact and limited wifi possibilities for a phone meant that ID was frustratingly delayed.
This butterfly turns out to have the wonderful names Two-tailed Pasha or Foxy Emperor (Charaxes jasius). Frankly either name is exotic enough to stick in the mind, but I think I prefer the Pasha. Because the creature was on a tree beyond the parapet, there was no chance I could get near enough for a close-up, so I had to resort to zooming in at various angles and magnifications, and hoping for the best.
I kept hoping the butterfly would move without going to the extreme of flying away. An open wing shot would have been great to get, but it was not to be. Here’s what the upper wings look like. Having found the image, I realised at once that we saw one or two of the same species on the wing elsewhere, but they were too busy to pause for a photograph.
These are butterflies of Africa, but they are also found on the southern fringes of mediterranean Europe. Apparently they like maquis-type scrub country or (clearly) the similar garrigue terrain where we were. They also like some height, although we were only about 1500 ft ASL.
This is the first year that leaf-cutter bees have discovered the bee box placed invitingly on a south-facing wall – and only in the last month. Or maybe they had and didn’t like the box. Or the other occupants. Anyway, quite soon they had tenanted the remaining holes in the prestige penthouse log.
Last week, the LCBs were quite active, so from time to time I watched them. The first one was completing its work in the top-right log on the lower storey. Having packed in the leaves, it spent quite some time perfecting the job, leaving a smooth end to the bright green plug.
Later on I saw a bee engaged in an earlier stage of construction. It chose the same log, and initially went for the middle hole, disappearing with a strip of leaf. It then revised its accommodation plans, reversed out with the leaf and took it to the adjacent hole.
I found the bees surprisingly difficult to photograph. I had to change cameras to a ‘faster’ one, because a bee would zoom back to the hole with its leaf and dive straight in, dragging the leaf behind it; and emerge suddenly and fly off at speed. Sometimes there was a struggle to get the leaf into the hole, which helped take a shot; or I could see the bee pause in the dark but quite close to the entrance before flying off. But mostly, the comings and goings took me by surprise every time, even though I was ready for them…
I checked the plants in the vicinity for the tell-tale semi-circles cut out of the leaves. They seem to have liked a nearby rose and another plant whose name I forget (if I ever knew). They use saliva to glue the cuttings together to build the cells for their larvae. The larvae have a safe place to hatch and develop. They pupate in the autumn and hibernate during the winter. Now that the leaf-cutters have found the box, we are hoping that next year the new generation will go through the whole process again. And that I will be more handy with the camera.
NOTE: I see that these bees are often called Leafcutter bees, or Leaf Cutter bees, whereas I have plumped for a hyphen. I’m going (having retrospectively checked) with the Natural History Museum’s version…
While photographing bees last week I encountered a smartly marked hoverfly. I was particularly impressed by its striped head. I have to admit that until I looked into it, I has assumed that there were maybe half a dozen different species in the UK. I’ve never really examined them closely until this one flew into my lens range.
How wrong I was. Fortunately by googling ‘hoverfly ID’ my first hit was a wonderful site about the natural history of Rutland and Leicestershire called NATURESPOT. The link will take you to their hoverfly page, from which you will learn that “There are over 280 species of hoverflies in Britain and around 140 of these have been recorded in Leicestershire and Rutland”.
Additional useful information includes this lightly edited précis:
- Many have black and yellow markings and are often confused with bees and wasps
- Hoverflies are totally harmless and are definitely a gardener’s friend
- The larvae of several common species have a voracious appetite for aphids
- Very few hoverflies have common names
- Those that exist (e.g. “The Footballer”) are not always widely known or agreed
- However the Latin names of all the species are accepted
This is the best (though somewhat average) in-flight shot, included to show the trailing back legs
I had to scroll quite far down the hoverfly page to reach the striped-headed ones. Here’s a clip of the part that I used for a clear ID as Helophilus trivittatus. I highly recommend Naturespot not just for hoverflies, but for many different species. It may be local to a specific area, but it is a mine of information for the UK generally, and very well organised.
Hoverfly weblink: http://www.naturespot.org.uk/taxonomy/term/19415