FIND OUT MORE. Arthropods 107 • Reproduction 101 • Senses 99
Nature^111
COLONIES
HOW DO SOCIAL INSECTS RAISE THEIR YOUNG?
Most insects take little or no care of their young, but
social insects are an exception. Workers carefully
guard the young and bring them food. Worker wasps
bring chewed-up insects for their grubs (larvae).
Honeybee grubs are fed on honey. These young
insects grow up in a nursery at the heart of the nest.
TERMITE QUEEN WITH
SOLDIERS AND WORKERS 3
Each insect colony contains
several different castes, or ranks.
The queen’s job is to lay eggs –
queen termites are so full of
eggs they cannot move. Large
numbers of non-breeding female
workers tend to the eggs and
maintain the nest. Many insect
colonies also have a defensive
caste of soldiers, armed with
huge jaws or poison.
Most insects live solitary lives, but termites,
ants, and some wasps and bees live together
in large colonies. Members cooperate in
building the nest and finding food.
MONARCH CATERPILLAR 3
Many insect larvae (young) look
very different from the adults.
Moth and butterfly larvae are
known as caterpillars. These feed
on leaves, building up a lot of
weight in a relatively short time.
They then stop feeding and
develop a solid body case in
which they pupate (change) into
their adult body shape.
Compound eye
made of dozens of
six-sided lenses
Antenna
Wing covered with
thousands of tiny,
overlapping scales
4 MONARCH BUTTERFLY
After metamorphosis (the
change from larva to adult), an
adult monarch butterfly emerges from its
pupal case and slowly pumps up its wings.
Like all butterflies, the monarch butterfly
feeds on nectar produced by flowers.
WHAT DO INSECTS EAT?
Insects eat a huge range of foods. Around half are
plant-eaters, feeding on leaves, roots, seeds, nectar,
or wood. Praying mantises are predators, hunting
other small creatures. Fleas and lice are parasites,
eating the flesh or blood of larger animals without
killing them.
HOW DO INSECTS DEFEND THEMSELVES?
Many insects are camouflaged (naturally disguised),
so that predators do not see them. Some species are
armed with stings or foul-tasting poison. Many of
these have bright colours, such as black-and-yellow
stripes, to warn enemies away.
HOW DO INSECTS AFFECT HUMANS?
Plant-eating insects can harm crops and fruit trees.
Wood-munching termites destroy homes and furniture,
while biting insects can spread disease. However,
many insects are helpful to humans – for example,
honeybees make honey, ladybirds eat aphids (which
damage garden plants), and silkworms produce silk.
4 COCKCHAFER BEETLE
In beetles such as this
cockchafer, the front wings have
evolved into tough, rounded
cases called elytra. These protect
the delicate back wings from
damage when the beetle is on
the ground. The elytra are lifted
out of the way as the beetle
takes off and flies.
Pupal case
in which the
butterfly pupated
(changed) from
a caterpillar
Feathery antennae
Elytron (wing
case) fully open
and raised
Back wings unfold
WHERE DO INSECTS GO IN WINTER?
Many adult insects die off in winter.
Their eggs or young survive in sheltered places
and emerge in spring. Some insects survive the cold
by hibernating. Others, such as monarch butterflies,
migrate long distances to avoid the winter chill.
HBUTTERFLY
insects