November 2018

One of the really pleasurable aspects of writing these Nature Notes is that people come to me with nature-related questions or send me photos of things to identify.  Most of the time I have a good idea of the answers, or at least a good idea of where to go to look for the answer.  One question was “Why so many crane flies?”.  My answer (Perhaps because of the dry summer making the ground hard and so difficult for birds to eat the leatherjackets.) was completely wrong.  The correct answer is the wet autumn of 2017 which allowed the leatherjackets to thrive, and also, the fact that certain insecticides have been banned which used to poison the leatherjackets (and lots of pollinators too!).  But at least I now know, and I had the pleasure of trawling the internet to look it up.

One of the Facebook groups I belong to also spawned a trawl for more information.  Somebody had opened a bird box that had been home to a bumblebee colony and was asking what the white fibrous material was.  Somebody had answered that it was the silk of Aphomia which is a parasite of bumblebees, honey bees, and wasps.  So I then wanted to know what Aphomia was – it is better known as the Bee Moth or Aphomia sociella. 

Bee Moth - Aphomia sociella

The female bee moth lays her eggs in the colony early in the season – i.e. before the first workers hatch to build up the colony’s defences.  When the bee moth larvae hatch they will eat eggs, bee or wasp larvae, and any pollen or nectar they can find.  (The caterpillars spin a particularly strong silk cocoon to protect themselves while feeding.)   So if you do clean out your bird boxes – and now is a good time to do it – then please destroy any caterpillars you find in there, and just be aware of queen wasps that often use nest boxes to hibernate in.  If you want to attract birds to your nest box, then clean out any old nesting material, but if you want to attract bumblebees, then leave the nesting material in there, or better still get another nest box and do both.

One interesting thing that I found out about bee moths was their mating habits.  Most female moths emit pheromones when they are ready to mate, and most male moths have large feathery antennae so that they can detect them.  In the case of male bee moths, they also emit their own pheromones to increase their chances of encountering a female.  But the really interesting thing about the male bee moth is that he has another weapon in his charm arsenal – he can emit ultrasonic ‘chirps’ in much the same way that cicadas do so that the females can more easily find him.  What I’d be interested to know if I was a male bee moth is – can bats detect my ultrasonic ‘chirps’?  I also found out that the sound is emitted from the tegular tymbals, but nobody needs to know that unless they accidentally come across a pair.

To move away from the endlessly fascinating world of insects for a moment – there are a lot of jays about just now.  There a lot of jays about all the time, but at this time of year they are collecting and caching acorns and other seeds, and so are more conspicuous.  They are the most colourful of the crow family with their beautiful dark pink plumage and pale blue wing flashes.  Like other members of the crow family they are very intelligent and will remember where most of the seeds are buried so that they do not starve through the winter when other food is scarce and energy demands are high.  One fact about jays that can help with identification is that they are the only crow-sized bird with a white rump, a useful feature since most birds are seen when flying away from you.

It seems to be a good year for parasol mushrooms.  They’re edible and delicious fried in a little butter.

Stop Press:  An Asian Hornet has been spotted at Dungeness.  The Asian hornet is more of a threat to honey bees than its larger cousin the European hornet.

When this article went to press for the printed version, I had confused Bee moths (Aphomia sociella) with the similar Wax Moth (Galleria mellonella).  The Wax Moth is normally found in honey bee hives as its larvae feed on honeycombs - particularly old honeycombs so that they are less of a burden to the colony than Bee Moths.