Saturday, 14 July 2007

Moth Trap interlopers

When I open my moth traps in the morning, to see what species have put in an appearance, it isn't only moths that are there to greet me. Various beetles and flies are attracted to the light of the trap. Here are a couple of the more spectacular arrivals last night.

This is one of the largest Hoverflies that we have. Its name is Volucella zonaria and it belongs to the family of insects known as Syrphidae. Like all true flies, Diptera, it only has one pair of wings, Bees and Wasps have two. Although they mimic Bees or Wasps they don't sting and are completely harmless, in fact they are the gardeners friend as their larvae eat pest species.

The eyes are huge, but as you can see on this picture they are composed of thousands of small lenses (compound eyes). Unlike bees or wasps they have very small antennae. This one was very dozy and let me take a few photos before it suddenly woke up, started buzzing and flew off. As it name suggests it has a characteristic way of flying, hovering in one place before darting off to a new point.

In May and June I catch Cockchafers, but I was surprised when I started catching them again in July. But they're not, these are Summer Chafers.

This is a hairier relative of the Cockchafer but much smaller. The beetles fly in companies, on warm summer evenings before dusk. They are approximately 20mm long and are found in meadows, hedgerows and gardens. Their numbers are declining, although where found, they are often seen in large numbers.

Looking head-on you can see the two clubbed appendages on either side of the head. I think that these are used for balance and direction when flying, rather like gyroscopes, but I'm not too sure of the mechanism of it.


tut-tut said...

These are very fine photographs, not just because they are visually srtiking, but because they, along with your brief natural history comments, may well inspire interest and curiosity about the insect world where it did not exist before.

I think the two bulbous appendages to which you refer are palps, part of the mouth's assemblage of machinery. They most probably contain ensory capacities that detect food and moisture.

Did you know that houseflies taste with their feet? You might well enjoy a book, "To Know a Fly" by V. G. Dethier--quite informative with a healthy dose of humor.

Also, next time you observe Syrphid adults, note that they are among nature's most agile predators.
While hovering they are also observing, hunting. You may see one snatch prey, if you have good luck--from your point of view, of course, not the prey's.

Tony Morris said...

Hi tut-tut, thanks for your comments. I am always surprised by what can be done with a Nikon Coolpix 4500, it must be one of the best "cheap" cameras made for taking macro pictures. It out performs what I can do with a much more expensive SLR with a macro lens because of its ease of use. Thank you for putting me straight on the palps,and for your other usful bits of information.