Dragonflies – graceful creatures are again on the danger list
WILDLIFE
One of the loveliest sights on a clear summer’s day is a dragonfly skimming a garden pond.
Yet these graceful creatures are on the danger list. We have lost three species in the UK during the past 40 years and a third of those remaining are threatened with extinction.
The British Dragonfly Society works to educate and help the conservation of these very special insects with dramatic names such as Brown Hawker, Emperor Dragonfly, Azure Damselfly and Blue-tailed Damselfly.
The more we know and understand them the more we can do to help conserve them. Their story is remarkable: they belong to the most primitive group of insects, the order of ‘odonata’ which means ‘toothed jaws’, as they are voracious hunters even as larvae.
They have been around for millions of years. Some of their prehistoric ancestors 300 million years ago reached a wingspan of up to 70cm (almost 2ft, 4ins) and could fly at 30 mph. Fossil records clearly show dragonflies, and they predate birds by 150 million years.
Modern day versions are still quite alarming at close quarters for many of us, but they are harmless, do not bite or sting and if one is trapped inside the house might actually sit on your finger.
The difference between dragonflies and damselflies
The first thing to understand is the difference between them – and it’s quite easy. Dragonflies are generally larger, with a thicker body, huge eyes and broad wings which are almost always fully open.
Gardeners can help the conservation of dragonflies
overhanging trees giving shade
plants
good zoom lens. Find out the species in books and websites
trust or to the British Dragonfly Society
Dragonflies do not bite or sting and if one is trapped inside the house might actually sit on your finger
Damselflies as their name suggests, are daintier, with long, thin bodies, narrow wings which close when at rest and held over their ‘backs’, and smaller eyes – although these are very large in proportion to the rest of their anatomy and protrude from the sides of their head as if on stalks.
Dragonflies and damselflies come in many bright colours: blue, red, orange, brown, yellow and green.
They have a two-stage life cycle, unlike some other insects, going straight from larvae to adults, without the pupa stage in between. Eggs are laid by female dragonflies on vegetation under water or directly into water, and are hatched after 2-5 weeks. Some eggs laid late in the summer will not hatch until the following spring.
Most of the eggs stay as larvae for up to two years, the larger ones taking up to three years, and the hunting instinct shows itself right away, preying on a range of tiny underwater creatures. The Golden-ringed Dragonfly can be in the larval stage for up to five years.
Larvae will climb out of the water on a stem of reed or other plant, and emerge as adults. At this time they are vulnerable to predators, as their wings are not ready. When the wings are full of fluid which then has dried out, they take flight. The life of adult dragonflies is quite short – in this country just a few weeks, although in hotter, drier countries they can live for several months.
At least 55 species have been recorded in the UK, of which around 40 are resident. There are over 5000 species worldwide.
46
Country Gardener
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56