October 2018

You may remember that last month I wrote about hornets feeding on wasps.  I suspected that they leave the wasps’ abdomen because there is more protein in the thorax where the leg and wing muscles are located.  On a recent visit to Belgium with the short-haired bumblebee project, we met up with some Dutch and Belgian entomologists.  I was talking to one of the Dutch entomologists about the hornet and he confirmed that they only take the thorax for its protein content.  He also said that they don’t eat the thorax, but rather they mash it up into a manageable meatball and carry it back to their nest to feed the growing larvae.  Like their more useful cousins, the honey-bees, they make a bee-line for the nest.  Apparently, Holland has been dealing with the westward spread of the Asian hornet for a while now and they use this ‘bee-line’ habit to locate their nests.  All they need to do is to find a hornet and when it flies off with its meatball, plot its direction on a map.  When you have watched and mapped two or three hornets in this way, where the lines intersect shows you where to look for the nest, which can then be destroyed.  This may well be useful knowledge since as recently as the 11^th of September, Asian hornets have been spotted in Cornwall and East Yorkshire.

Great Green Bush-cricket - female

Another group of insects that we saw plenty of in Belgium were bush-crickets.  This is a striking group of insects and they are remarkable for the length of their antennae which can be many times longer than the rest of the insect.  We saw the great green bush-cricket, which as its name suggests is big and green.  The body can be up to 40mm long, and with an ovipositor another 20mm and antennae three times longer than its body, it looks a formidable insect.  I first came across one of them at Dungeness and my first reaction was one of disbelief.  It was bending the vegetation that it was crawling across.  Though large, they are well camouflaged in green vegetation and can move fairly quickly.  You are more likely to hear them before you see them as they have the loudest stridulation (chirping!) of any of our grasshoppers or crickets. 

Great Green Bush-cricket - male - showing just how big they are

We also found one species of bush-cricket that you are less likely to find around here - the sickle-bearing bush-cricket.  These were spotted in Hastings Country Park a couple of years ago, but have since disappeared again.  However, like many insects, global warming is inducing them to march northwards, and there have been other sightings around the country so if you see a bush-cricket with a sickle-shaped ovipositor, then take a photo – it may be a sickle-bearing bush-cricket – and the people who monitor such things want to know about it.

Sickle-bearing Bush-cricket - on my hand

I recently found one of my favourite bush-crickets – a speckled bush-cricket, on some red-leaved kale that we are growing.  Being bright green, it stood out well on the dull red of the kale.  With its long-legged awkward gait and its slightly goofy face, anybody would find it endearing, wouldn’t they?

Speckled Bush-cricket

Dave Clarke has recently had a small infestation of solitary bees in his garden.  They are probably ivy bees, another species on the march northwards (first seen in the UK in 2001).  I say probably, because there are two other very similar species – the sea aster bee and the heather bee.  (Dave's bees have since been confirmed as Ivy Bees.)  They are all called plasterer bees because of their habit of lining the cells that they dig in soft ground with a smooth cellulose substance.  You’ll have noticed that each of these bees is named after the plant that it prefers to feed on.  In Belgium one of the Belgian entomologists caught and identified a solitary bee from the fact that it was feeding on purple loosestrife, (which incidentally has green pollen).  It was one of the blunt-horn bees (Melitta nigricans) that we don’t get in the UK – yet!

Ivy Bee - Colletes hederae