Equinoctial celebration

For most of today I expected to be posting either the Green Shieldbug I found on the honeysuckle this morning, or an Early Bumblebee which was working one of the gooseberry bushes in the secret garden. But late this afternoon, with the sky blackening as a band of rain arrived, I was back out in the garden on yet another fruitless hunt for Bee-flies, when I spotted this pair of weevils celebrating the vernal equinox on what I think might be a bird cherry sapling in our nascent wildlife hedge. 

It was so dark by this stage that I had to push my settings a long way out to be able to shoot at all, and with the aperture too wide and the shutter speed too slow for successful macro it was then a question of spraying and praying, and hoping that a few (out of several dozen) frames would be usable. In the end only this image successfully caught the eyes and snouts of both participants, but - provided you ignore the legs, antennae, and pretty much everything else - this lets me claim that it's in focus. Either of my other candidate photos was technically better, but.... well, you know. Bug porn: I simply can't resist.

I'd like to be able to tell you more about these weevils than I'm able to, but very little seems to have been written about them. After some discussion a couple of years ago with the guy who validates the weevils on iRecord, I'm confident in saying that they're Involvulus caeruleus (otherwise known as Involvulus icosandriae), and are sometimes known as the Apple Twig Cutter Weevil. The males are about 2.5mm long, and the females about 4mm, which makes them only marginally longer than Oxystoma pomonae, but they're also broader, with much squarer wing cases, and this makes them appear generally bigger and more robust. They're also a much brighter blue, and noticeably hairy, so I never have to look too hard to distinguish the two species. 

Whereas Oxstoma pomonae lays its eggs into the seed pods of various vetches, the female Involvulus caeruleus cuts into a fruit tree twig, lays an egg, and then nips through the twig to break it behind the egg, so that the larva develops in the damaged end. For this reason the species is regarded as a pest in commercial orchards, but even though they seem to be increasing in number in our garden (I've found half a dozen over the past couple of days, including this pair) I've not yet noticed significant damage to our fruit trees. In any case, I take a live and let live approach to most garden pests (the neighbour's cats excepted), so these pretty little weevils are quite safe from me.