PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
BIOLOGY
Phylum Arthropoda, Class Insecta
Insects are the most abundant and most diverse of all animals. More than 86,000 species of
insects have been identified in Australia and probably a similar number are awaiting discovery. It is
likely that some may become extinct without ever having been discovered!
CSIRO Insects and Their Allies www.ento.csiro.au/education/about.html
SOME
BENEFIFICAL
INSECTS
Wasp laying
an egg in a
scale insect
POLLINATORS OF MANY PLANTS
Bees, wasps, flies, beetles and other
insects are important pollinators of crops.
Bee
FOOD SOURCE OF MANY ORGANISMS
Bats, birds, fish, frogs and lizards feed on many different types of insects.
Humans and animals feed on honey, bogong moths, witchetygrubs (woodboring
larvae, sometimes called bardee grubs), termites can be roasted.
Plants such as the Venus fly trap, feed on flies.
FEED ON AND RECYCLE ANIMAL AND PLANT WASTES, DEAD ANIMALS
Garden maggots in compost heaps digest and biodegrade organic matter.
Dung beetles bury and decompose dung.
PARASITES AND PREDATORS OF MANY PLANT AND ANIMAL PESTS
Red scale of citrus can be controlled biologically by parasitic wasps.
Insects may also transmit biological control agents, eg mosquitoes transmit
the myxomatosis virus used to control rabbits.
PRODUCE ITEMS USED BY HUMANS
Beeswax, shellac, dyes, silk, medicines, royal jelly, red food colouring
products are all used in today's society.
AESTHETIC VALUES
Beautiful insects especially butterflies are collected.
Wings of dead butterflies in some parts of Africa are used as an art form to
create pictures. Butterflies and beetles are used as head or body decorations.
SOME
HARMFUL
INSECTS
Weevil
chewing
leaves
MOST INSECTS AND ALLIED PESTS ARE NOT ‘PESTS’!
Less than 0.1% of the nearly 1 million known species are harmful.
‘PESTS’ OF PLANTS AND ANIMALS
Plants may be damaged by aphids, fruit flies, scales and other insects.
Stored products by grain moths, grain beetles.
Paper, leather and textiles by beetles, cockroaches, silverfish, moths.
Animals by blowflies, fleas.
Humans by fleas, scabies, mosquitoes, ticks, lice, bedbugs.
Many insects are nuisance pests, eg bush flies, many ants.
Some ‘stinging’ insects, eg bees, wasps, and some ants inject poisoning and
paralyzing liquids via a modified egg-laying structure. Some ‘biting’ pests
pierce the skin to feed on blood; many dogs are infested with ticks each
year and some may die from tick paralysis.
Arachnophobia is a fear of spiders.
TRANSMIT DISEASES OF PLANTS AND ANIMALS
Plants, eg tomato spotted wilt virus is spread by thrips.
Humans, eg malaria (a protozoa) is spread by a species of mosquito which
pierces the skin (‘bites’) to feed on blood.
Insects and allied pests - Biology 7