Arthropods

1
Arthropods
By Hannah Burton 7q
2
Ladybirds
There are over 5,000 species of ladybirds
world-wide and more than 500 species which occur
here in Australia!
Most Australian ladybirds eat scale insects and
aphids and help control these insect pests in
gardens. The most common ladybird in the
Canberra area is probably the spotted ladybird,
Harmonia conformis. The Botanic Gardens in
Canberra uses ladybirds to help control insect
pests in its glasshouses. Most Australian
ladybirds live under the bark of eucalypt trees
and eat scale insects. Ladybirds can be tiny,
some species are only 2mm in diameter. Not all
ladybirds have spots, many species are plain
black or brown. Male ladybirds and usually
smaller then females. Ladybirds taste terrible
they produce a chemical which makes them
unpleasant for birds and other predators to eat.
Female ladybirds can produce over 100 eggs over
their life. Some people have used crushed
ladybirds to stop toothache yuk! Australian
ladybirds were the first biological control
agents! The vedalia ladybird, Rodolia cardinalis,
was sent to the USA in 1888 to control cottony
cushion scale insects in citrus orchards. In
Europe in the past ladybirds were thought to be
able to predict the weather, if they fell off
your hand it would rain, if they flew away it
would be fine.
3
Spiders
Spiders (order Araneae) are air-breathing
chelicerate arthropods that have eight legs, and
chelicerae modified into fangs that inject venom.
In their bodies the usual arthropod segments are
fused into two tagmata, the cephalothorax and
abdomen, joined by a small, cylindrical pedicel.
In all except the most primitive group, the
Mesothelae, spiders have the most centralized
nervous systems of all arthropods, as all their
ganglia are fused into one mass in the
cephalothorax. Unlike most arthropods, spiders
have no extensor muscles in their limbs and
instead extend them by hydraulic pressure.
4
Scorpions
Scorpions are any arachnid of the order
Scorpionida. They are members of the order
Scorpiones within the class Arachnida. There are
about 2,000 species of scorpions, found widely
distributed south of about 49 N, except New
Zealand and Antarctica. The northernmost part of
the world where scorpions live in the wild is
Sheerness on the Isle of Sheppey in the UK, where
a small colony of Euscorpius flavicaudis has been
resident since the 1860s.
5
Centipedes
Centipedes (from Latin prefix centi-, "hundred",
and Latin pes,pedis, "foot") are arthropods
belonging to the class Chilopoda and the
Subphylum Myriapoda. They are elongated metameric
animals with one pair of legs per body segment. A
key trait uniting this group is a pair of venom
claws or forcipules formed from a modified first
appendage. This also means that centipedes are an
exclusively predatory taxon, which is uncommon.
Their bites may have effects ranging from mild
discomfort to life threatening.
6
Thank you for watching