Dragons and Damsels in the north-west…
Dragonflies and damselflies may be seen in many parts of the Highlands and Islands during the summer, darting about chasing their prey.
The photo shows a golden-ringed dragonfly, with its distinctive yellow and black banding, which can often be spotted in the summer time. The female golden-ringed dragonfly has a long tube for laying eggs, called an OVIPOSITOR, which you may be able to see at the end of her body. It is the only dragonfly in the British Isles which lays its eggs in mud or soft peat, the other dragonflies do not have an ovipositor and lay their eggs in water or water plants as do damselflies.
Tarbh-nathrach seems to be a widespread Gaelic name used for both dragon- and damselflies. Do you know other Gaelic names for these insects? Dragonflies and damselflies make up a group of insects called the “Odonata”, meaning “toothed”, as these carnivores have strongly toothed jaws for biting their insect prey. There are about 42 species living in the British Isles.
There are several ways to tell quickly whether you are looking at a dragonfly or damselfly.Their huge compound eyes, with up to 30,000 tiny light-sensors, make them very efficient hunters : dragonfly eyes are set closely together on the front of the head; whereas damselfly eyes are wide apart, located on the sides of the head.The hind wings of dragonflies are sometimes broader than the front pair and when resting the wings are outspread. The two pairs of damselflies’ wings are about the same size and are folded vertically or partly open above the body when the insect is resting. Dragonflies tend to be longer and broader than damselflies, but that’s only helpful once you’ve seen several species of each group !
In mid-summer you might catch sight of a mating pair flying joined together, this is called “in tandem”, usually over water. The eggs hatch into nymphs which live in freshwater, breathing with gills which are visible at the backend in damselflies. They are fierce carnivores, even eating large tadpoles. Dragonfly nymphs take between 1 to 5 years to develop, depending partly on temperature and how much food they have. While they are growing they will shed their skin up to 15 times! The adult dragonflies and damselflies emerge during the summer, and only live for about a month. Most British damselflies have a life cycle of around a year.
Dragonflies can be classed in two groups by the way they hunt for the smaller insects on which they feed : the longer-bodied ‘hawkers’ which patrol over water or damp ground; and the squatter-shaped ‘darters’ which tend to rest on vegetation and zoom into the air when suitable prey appears.
Dragonflies are amongst the fastest and oldest insects in the world. They have been recorded flying at over 35mph – it didn’t say if this was in a built-up zone ! The fossilised remains of these insects have been found in rocks, which tells us that they have been flying around for 300 million years!
Dr. Mary Elliott