In this blog I consider why there are different female colour forms (or morphs) in some damselflies, such as the Common Bluet, and briefly discuss some of the theories which attempt to explain their existence. In Enallagma species (Coenagrionidae) – called Bluets – males usually start searching for mates before females have appeared. Some males…
Tibial spurs are an ancient feature, found on most insects, from bees to moths, although in some species they have been lost or modified over evolutionary time to suit the adaptive needs of different groups. So the size and shape of this implement – rather like the blades on a Swiss army knife – is…
The subject of reduced or modified forelegs in butterflies might strike some people as being rather obscure, but it is – as I hope to demonstrate – a fascinating tale of evolution and adaptation. In addition, there is an awful lot of basic biology and behaviour which is not fully understood in many of our…
I was very pleased to come across this butterfly, the common birdwing, recently. Although it is fairly common, I had not had a chance to try and photograph it before. There are at least 25 subspecies of Troides helena, but because of the location, in northern Thailand, this is almost certainly, Troides helena cerberus (C.…
Dragonfly wings are thin and light and have a corrugated-like structure. There are lots of tiny cells between numerous veins and cross veins, which together form a stiff, yet relatively flexible structure which is able to bear alternating wing loads during the flight. Some veins are stiffer than others, particularly those at or near the…
The upper wing surfaces of butterflies are often brightly coloured and visually highly apparent (above), whilst the undersides are usually fairly dull and inconspicuous (below). Although this characterisation is a gross generalisation – there are plenty of exceptions – these differences between the two wing surfaces, do reflect their contrasting functions: upper surfaces are used…
Tiger beetles (Cicindelinae) are strikingly beautiful predatory insects which come in a bewildering variety of stunning colours: iridescent, metallic greens, reds, blues and so on. Researchers have speculated about the function of these gorgeous colours and have come up with theories to do with crypsis (blending in), disruption by iridescence (dazzle!), mimicry (trying to look like something…
The Common Blue is a gorgeous little butterfly. Although the bright blue male is flashy and showy, it’s the female I like best, with her subtle variations of blue and brown. Why these variations – blue to brown – persist and vary has puzzled scientists for many years; here I summarise some recent research on…
When I first came across this large spider, I wondered what it was doing with a piece of old leaf. Large Nephila spiders like this produce large asymmetric orb webs on which they sit, waiting for prey items to blunder into them. Amazingly, they construct these webs afresh every day, having consumed the old one to…
If you go to college (I studied Zoology) you learn a lot of exciting new words and phrases – things like parapatric speciation – very useful for impressing your friends at the bar (or maybe not!). Anyway, it’s a long time since I was at university and I must confess I had forgotten what parapatric meant! Researching…
