Re: bug question
In a message dated 05/27/2004 5:51:02 PM Eastern Daylight Time,
> have what is conceivably a dumb question about a very common insect. We
> call them squito eaters. Do they really eat mosquitoes and if so how the
> can they catch one? They seem to be the worlds worst flyers and look as if
> they are hovering over walls trying to catch something that has landed on
> walls. Can anybody tell me what is the story on these guys?
If dragonflies are what you are talking about, there is this that I prepared
for my club's newsletter a couple of years ago
It is said that virtue is its own reward. Is this also sometimes true of
beauty? Consider the butterfly. Butterflies are beautiful, without a doubt,
and for that reason they are highly prized. Their beauty is reproduced in
numerous materials, from fine jewelry to t-shirts. We see educational
about them on television. The migration of Monarch butterflies is one of the
wonders of the world, and their wintering site is a tourist destination.
Governments enact laws to protect their habitats. All this is because
beautiful and bring joy to our lives, and that's all well and good, but what
do they really do except flit languidly about, or just sit there and look
pretty? In fact when we speak of "social butterflies" we are referring to
who really contribute nothing but charm.
We even overlook the fact that in another stage they are caterpillars that
eat our plants. So, we say, they are so beautiful that it's worth giving up
some of our plants. Of course their close cousins, gypsy moths aren't pretty
and the damage they do is not tolerable.
Now let's consider the dragonfly. This is also a creature of beauty,
though not so flashy and colorful as the butterfly. The beauty of
lies in the delicacy of their wings, the brilliance of their eyes and the
and grace of their flight. And in the fact that they devour great quantities
of gnats, mosquitoes and other unpleasant insects, to make our life more
comfortable. Why do we not see and hear about this in the popular media?
Actually, a search of the internet turned up quite a bit of information
about dragonflies, including the fact that the green darner dragonfly is being
promoted as the state insect of Michigan; that another dragonfly is the state
insect of Alaska, and that there is a study currently being conducted of
migration patterns of dragonflies in the eastern United States. One of the
entomologists listed has a South Salem, NY address. There is apparently much
appreciation of these insects in Europe, as there were several European
associations and a number of studies giving information on European
Dragonflies are the world's largest and fastest insects, with a flight
speed of 30 - 50 miles/hour. There are about 6000 species known all over the
world. (There are only about 4000 species of mammals known.) The insect
Odonata is divided into three suborders: Anisoptera, or dragonflies;
or damselflies; and Anisozygoptera, a small suborder containing one Japanese
and one Nepallese species.
Dragonflies are characterized by an elongate body, agile flight, and two
pairs of membranous wings which are spread when resting. The hindwings are
slightly wider at the base and have a larger surface than the forewings
(Anisoptera means "unequal wings"). The adult head consists largely of
which may touch on top of the head. Antennae are short and hairlike.
are adapted for biting and scooping prey from the air. The legs are located
far forward on the body and are used mainly to grasp a resting spot such as a
twig. Most temperate-zone species of dragonflies have wingspans from 2 to 3.1
inches, but tropical species may reach a wingspan of 7.9 inches. The largest
known dragonfly lived over 270 million years ago in the late Carboniferous
and early Permian periods and had a wingspread of 29 inches.
Like other insects, dragonflies have a two-stage life cycle, but unlike
butterflies and moths, they do not damage our plants. Adult dragonflies mate
midair over fresh bodies of water in midsummer. The female deposits her eggs
in or near water. These eggs develop into nymphs that spend their life
entirely submerged. They may remain in nymphal form from one to three or more
years, during which time they may moult ten or more times. These immature
live as predators, normally feeding on other invertebrates. Nymphs crawl out
the water just before their final moult, which takes about 10 minutes, and
become winged adults which fly away over the land, only returning to the water
to mate and reproduce.
The adult dragonfly clings and climbs but does not walk. The males are
very territorial. An individual may stake out an area which he continuously
patrols, moving from one resting place to another and finally returning to the
first point, as he consumes passing insects. When a female enters his
he pursues her and grasps her behind the neckb&
Are these insects not as worthy of our attention as the butterfly? Perhaps
they just need better PR. Next time you see a dragonfly, appreciate its
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