Cool unbelievable facts about dragonflies part 2||THE APPU WORLD
Hello there today we are gonna learn cool unbelievable facts about dragonflies part 2!!
If you haven't watch part one of cool unbelievable facts about dragonflies then here's the link
What is the difference between Dragonflies and Damselflies?
Dragonflies and damselflies belong to the insect order known as Odonata, meaning “toothed jaw” – their mouthparts are serrated. They are often referred to collectively as “dragonflies”, however there are two different sub-orders.
Damselflies are insect in the sub-order Zygoptera (meaning “pair-winged” or “equal-winged”). All four wings are of a similar size and shape. They are usually small, weak-flying insects that stay close to the water margins or water surface. When at rest, most species fold their wings back along the length of their abdomen. The eyes are always separated, never touching. The larvae have external plates (lamellae) at the end of the abdomen, which act as accessory gills.
Dragonflies are insects in the sub-order Anisoptera (meaning “unequal-winged”). Their hind-wings are usually shorter and broader than their fore-wings. They are usually larger, strong-flying insects that can often be found well away from water. When at rest, they hold their wings out from the body, often at right angles to it. The eyes are very large and usually touch, at least at a point. The larvae have no external lamellae.
Do Dragonflies Bite or Sting?
No, although large dragonflies, if held in the hand, will sometimes try to bite they fail to break the skin. They have a lot of “folk names” which imply that they do, such as “Horse-stinger”, but they don’t use their egg-laying tube (ovipositor) for stinging. Nor do they attack people, though they are fearsome predators of other flying insects.
How long do Dragonflies live? Is it true that they only live for one day?
At the shortest, a dragonfly’s natural life-cycle from egg to death of adult is about 6 months. Some of the larger dragonflies take 6 or 7 years! Most of this time is spent in the larval form, beneath the water surface, catching other invertebrates. The small damselflies live for a couple of weeks as free-flying adults. The larger dragonflies can live for 4 months in their flying stage. In Britain, lucky Damsel adults seldom manage more than two weeks and Dragons more than two months. Most Damsels rarely go more than a week, and Dragons two or three weeks. They die from accidents and predation, and large numbers from starvation – in poor weather neither they nor their prey can fly.
No insect has a lifespan of only one day – even mayflies (not closely related to dragonflies) live for several months underwater as larvae before emerging as winged adults. Adult mayflies may only live for a day or so as they are dedicated “breeding machines”. They cannot feed as adults as most species don’t have any functional mouthparts.
How fast do they fly?
The maximum speed of large species like the hawkers is around 10-15 metres/sec, or roughly 25-30 mph. Average cruising speed is probably about 10 mph. Small species, and especially damselflies, are generally slower, although many medium-sized species can probably keep up with the largest ones.
How quickly do Dragonflies get their adult colour?
When dragonflies and damselflies first emerge from their water-borne larval stage, most have very muted colours. Depending on weather conditions, it can take a few days for them to gain their bright adult colour. Common Blue damselflies are often a pale pinkish-brown rather than sky-blue on first emergence. Some damselflies undergo a gradual colour change as they age, for example the Blue-tailed Damselfly. The females have several different colour forms and some change from violet to rich brown while others go from salmon-pink to blue. Some of the larger dragonflies also change colour as they age. Older females may start to develop the colouration of the males. Examples are Common Darter, which goes from yellow-brown to reddish brown, and Black-tailed Skimmer, which goes from yellow-brown to a blueish-grey.
What do Dragonflies eat?
Mainly, adult dragonflies eat other flying insects, particularly midges and mosquitoes. They also will take butterflies, moths and smaller dragonflies. There is one Asian species which takes spiders from their webs!
The larvae, which live in water, eat almost anything living that is smaller than themselves. The larger dragonfly larvae are known to catch and eat small fish or fry. Usually they eat bloodworms or other aquatic insect larvae.
How good are dragonflies’ eyes?
Dragonflies have extremely good vision, which they use to locate and catch small insects in flight. Like most insects, they have compound eyes. In the case of dragonflies the eyes contain several thousand individual facets, each containing a tiny lens. Each individual lens has a low resolution but by combining the images from all of them dragonflies can achieve a level of resolution that is better than most other insects and thus their sight is particularly good. They use their amazing sight to catch other insects in flight, in addition to spotting potential mates and predators. Visual acuity varies between species, with migratory dragonflies having the best sight and damselflies with their rather smaller eyes somewhat less, but still very good.
👍👍
ReplyDelete