Abdomen is
long and slender
to balance insect
when flying
Claspers are used by
male to hold female
during mating
Thorax (middle
section of the body)
Large compound eyes
give wide field of vision
1 BED BUG
Various insects feed on blood, including head lice, mosquitoes, and fleas.
The bed bug lives in mattresses and emerges when it feels the heat of a
body. Its mouthparts are adapted to pierce skin and suck up blood.
INSECT CLASSIFICATION
Insects
Wings held together at
rest – unlike dragonflies’
wings, which are
held open
Long, delicate
legs have
several joints
Head
WHY ARE INSECTS SO SUCCESSFUL?
The main reason for insects’ success is their variety.
There are so many species that there is almost nowhere
on land they cannot live, and almost nothing they
cannot eat. Their small size enables them to go almost
anywhere in search of food. Many insects can fly,
which makes it easy for them to colonize new places.
1 DAMSELFLY
Like all adult insects, damselflies
have three-part bodies, with a
head, thorax, and abdomen.
Damselflies and dragonflies form
a very ancient group of insects.
Giant dragonflies flew in swampy
forests 350 million years ago,
before dinosaurs existed.
- Insects have thrived on Earth
for over 400 million years.
The insect world is divided
into 29 groups, called orders. - The largest order, the beetles
(Coleoptera), contains more
than 370,000 species.- Other major orders are moths
and butterflies (Lepidoptera,
165,000 species), bees, wasps,
and ants (Hymenoptera,
198,000 species), flies (Diptera,
100,000 species), and bugs
(Hemiptera, 80,000 species).
- Other major orders are moths
The most numerous animals on Earth, insects form about
75 per cent of the animal kingdom. Around 800,000 species
have been identified, but there could be up to 10 million.
Insects are six-legged invertebrates with keen sense organs,
including. ANTENNAE. Some live in. COLONIES.
BUTTERFLY SENSES 3
Long antennae and large
compound eyes help butterflies
to sense the world around them.
ANTENNAE
Club-shaped antenna,
different from the feathery
antenna of a moth
WHAT DO INSECTS USE THEIR ANTENNAE FOR?
Insects use antennae to find food and detect enemies.
Lice, fleas, and other insects that feed on other animals
use their antennae to sense the body heat or moisture
of their victims. Some male insects have especially
sensitive antennae, which can pick up scents called
pheromones given off by females (their mates).
WHAT OTHER SENSES DO INSECTS HAVE?
Many insects have compound eyes, with dozens of lenses
that work together to form a detailed picture. Some also
have sensitive bristles on their abdomens, which detect
air currents caused by moving predators or prey. Insects’
eardrums may be on their legs or body. Some insects,
such as flies, have taste organs on their feet.
The main sense organs of most insects are the antennae (feelers)
on their heads. These often long and slender projections are covered
with tiny sensitive hairs. As well as feeling, the antennae are also
used for smelling, and sometimes for taste and hearing, too.