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Insects in Spring
Many people think that at the end of summer
all the insects die. Obviously, this is nonsense. Where would
the insects that are seen in springtime come from? Many
insects pass through winter in a resting stage, as eggs or as
pupae. Insects, such as dragonflies, have larvae called nymphs
which are aquatic (meaning they live in water). These nymphs
can remain quite active during the winter period, as long as
the water does not freeze.
Only the adult insects are sexually mature.
In springtime the eggs and pupae, which have spent the winter
in a dormant state, complete their development. The adults
which emerge from the pupae lose no time in finding mates.
Most adult insects have wings and, before
she lays her eggs, the female may fly quite a distance to find
a suitable supply of food for the next generation. This helps
to disperse the species.
The majority of insects metamorphose as
shown by the following life cycle of the cabbage white
butterfly.
The larvae are sexually
immature. Their function is to eat and grow. They need to shed
their skin a few times in order to increase in size. This is
called moulting. At the final moult, the skin becomes hard as
the insect enters its pupation. Inside the pupa the tissues of
the larva are broken down and re-arranged into the adult form.
After a certain period of time, which may be over the winter
months, an adult insect emerges from the pupa. The cycle is
now complete.
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Butterfly and moth larvae are called caterpillars
Beetle larvae are called grubs
Fly larvae are called maggots
The pupa of a butterfly is called a chrysalis
The pupa of a moth develops in a cocoon of silk. |
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©
Paul Billiet, Shirley Burchill, Alan Damon and
Deborah James 2009 |
The Open Door Web Site
