PLANT PROTECTION 1 – Pests, Diseases and Weeds

PLANT PROTECTION 1 – Pests, Diseases and Weeds
ORDER ORTHOPTERA
Crickets, grasshoppers, katydids, locusts
NO. SPECIES
IN AUSTRALIA
SOME
DISTINCTIVE
FEATURES
LIFE CYCLE
In excess of 2,500 species. The general appearance of these insects makes this
order difficult to confuse with other orders. Resistance to pesticides has only
occasionally occurred.
www.ento.csiro.au/education/insects/orthoptera.html
The Australian Plague Locust Commission (APLC) may be accessed at:
www.daff.gov.au/animal-plant-health/locusts
ADULT Body Generally fairly large, no distinct constriction between
head and thorax. Many are well camouflaged.
Wings
Legs
1. Two pairs in adult. Some species with short wings or
without wings.
2. Forewing thickened, forming a cover over the hindwing.
3. Hindwing gauzy and plaited or fan-like.
4. Some males produce sounds by rubbing specialized
parts of the forewings, abdomen and/or legs together to
produce a characteristic song, eg crickets rubbing their
forewings together.
Hindlegs enlarged and developed for jumping.
Thorax Pronotum (upper surface of 1 st segment of the thorax) is
prominent, often saddle-shaped..
NYMPH Similar to adult, but smaller and wingless.
There is a gradual metamorphosis - egg, nymph (usually 5 stages) and
adult. It is difficult to produce a generalized life cycle for such a diverse order.
For example, locusts and crickets lay eggs in the soil but tree grasshoppers
or long horned crickets and grasshoppers lay them on leaves.
Australian
plague
locust
Adults are
20-45 mm long
There are many
variations, eg
spur-throated locust
has 1 generation
each year
METHOD OF
FEEDING
ADULT All stages have chewing mouthparts and mostly feed on plants,
NYMPH a few species prey on other insects. Many feed at night and rest
on plants during the day.
180 Insects and allied pests - Orthoptera (locusts)