desert bugs - Top That! Publishing

What is a plague of locust
Locusts usually live alone … until it rains. Rain provides
locusts with the perfect conditions to reproduce, and
they go into a breeding frenzy, producing millions –
and sometimes billions – of offspring. The close contact
between these insects can cause them to become what
is known as gregarious. They appear different to their
parents, changing colour from the usual green to
multicoloured pink, black and yellow, and form
enormous groups called swarms.
Locusts can cause serious damage to farmers’ crops.
With a single swarm thought to contain up to eighty
million locusts, imagine the damage that these hungry
insects can cause as they munch their way through any
plant in their path. Locusts live mainly in northern
Africa, but a swarm can travel huge distances into Asia
and even Europe, causing widespread devastation to
farmers’ crops and so leaving people to struggle
without food. This is known as a plague.
18
How do grasshoppers hear
Grasshoppers and crickets don’t have ears on their
heads, but they can still hear and feel vibrations. A
grasshopper’s ears (called tympanum) are on the sides
of its body, whereas a cricket’s ears can be seen as a
swelling just below each knee on its front legs.
How do they communicate
Listen carefully as you pass patches of tall grass in the
summer and you might be lucky enough to hear
crickets and grasshoppers chirping. This sound, known
as ‘stridulation’, is not made by a voice, but by a row
of bumps on the insect’s legs or wings. The insect rubs
its hind legs against its forewings or, in some cases,
rubs its wings together to make the noise. Each species
has a different arrangement of bumps, so the sounds
they make are unique. Next time you hear a
grasshopper chirp, take it as a sign that love is in the
air! It’s the males that ‘sing’ to woo the females and to
warn off other males.
The male ‘sings’ to woo the female before the pair mate.