Page 37 - The Miracle in the Mosquito

Phases of Development

Gelatin-covered eggs
Over the last ten years, effective methods have been devel-
oped for the preservation of foodstuffs. The most important of
these is packaging.
The variety of midge known as the Chironomidae (in the same
order, Diptera, as mosquitoes) uses this method to preserve its eggs.
The eggs are laid in a pile of gelatin-like substance, either in
the shape of a frame or a string. The gelatin mass protects the eggs
from being blown away, from drying up, from sudden changes in
temperature and from enemies. In addition, thanks to this sub-
stance the fly sticks the eggs to plants or stones and thus also pre-
vents the eggs from getting lost in the water.

Life buoy eggs
The eggs of the Anopheles mosquitoes, which serve as vectors

for malaria, have a special shape and structure to prevent their
sinking and enable them to stay on the surface of the water. Little
air chambers on the outside of the eggshell and floating edges sur-
rounding the egg keep it above water. The floating edges increase
the surface tension of the water and thanks to this tension the egg
does not sink.
Surface tension creates a force, which small creatures in par-
ticular cannot pass through. However, this is not usually a bad
thing as it enables insects to walk on the water with ease. Thanks
to support structures found on the legs of some insects, such as lit-
tle hairs or oily secretions covering the feet, they are able to move
much more easily on the surface of water.
The air chambers and floating edges on the eggs of the
Anopheles mosquito make great use of the physical law of surface
tension. However, as has already been mentioned, neither the lar-
vae inside the eggs nor the mother mosquito, who herself once
hatched from one of these eggs, has any knowledge of the surface

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