Organic Strategies for Grasshopper Control
© Frances Michaels
Regardless of where you live in Australia the noise of crickets and grasshoppers is one of the background sounds
of hot summer nights. The 'song' is produced by the male to attract a mate.
Crickets, grasshoppers and locusts as a group of insects are distinguished by strong chewing mouthparts and
enlarged hind-legs designed for jumping.
- Crickets are usually nocturnal, some like the tree cricket are predatory, others like the mole cricket
feed on roots and burrow in the soil.
- Grasshoppers are divided into short and long horned, with the ‘horns’ referring to the length of antennae,
in long-horned grasshoppers the antennae are longer than the body. Long-horned grasshoppers are large, mainly
plant eaters and often nocturnal.
- Short-horned grasshoppers, including the locusts, are active during the day. The name locust is given to
species that can occur in swarms. This includes the Australian plague locust, which has a black patch at the
tip of the hind-wing and some scarlet on the hind-legs.
Not all grasshoppers are plant-eaters; surprisingly some are predatory with front legs adapted for grasping prey.
Check before you accidentally squash a 'garden helper' by looking for spiny front legs.
Grasshopper eggs are mainly laid in the soil, although some do lay eggs on leaves. The eggs lay dormant until it
rains, sometimes for years. Once hatched, if conditions are right, the next generation can be produced within a
Crickets, grasshoppers and locusts attack a wide range of plants but it is in inland areas where the major impact
Physical and Cultural Controls
- The most important natural enemies of grasshoppers are birds. In inland areas the swamp ibis is
particularly important as a control for locusts and the draining of wetlands can increase locust plagues.
- Chickens not only like eating grasshoppers but seem to get a lot of entertainment catching them too! Keen
gardeners in inland areas should consider designing a chicken run with a shared fence between the chook run and
vegetable garden for as much of the garden perimeter as possible. This can reduce the fencing needed and create
a 'Fort Knox' style vegetable or flower garden as far as grasshoppers are concerned.
- Guinea fowl are hardy birds, not suitable for urban areas as they are noisy but they could be a big help on
larger properties, as they are famous for eating large numbers of grasshoppers and ticks.
- Other natural controls include sugar gliders, lizards, snakes, assassin bugs, frogs, ants, fungi and
- Beneficial insects such as paper wasps, tachnid flies and parasitic wasps prey on grasshoppers. Robber flies
are a major predator of grasshoppers, as they can make up to 1/3 of their diet. Habitat, such as a border of
perennial plants, needs to be available all year round as a refuge for these predators. They can also be
encouraged by planting suitable nectar-producing plants Good choices include
dill, caraway and anise.
- No commercial biological controls are available in Australia; in the USA it is possible to buy a predatory
protozoa Nosema locustae that controls grasshoppers.
Least Toxic Chemical Controls
- As a variation on the old adage ‘the early bird gets the worm’ this is also a good strategy with
grasshoppers. Catching them in the early morning is relatively easy, as they are less active in the mornings,
especially after a cool night. Either catch them by hand or use a butterfly net.
- Digging or cultivating in spring, and leaving the soil exposed, can expose the eggs to predators.
- Physical barriers such as
floating row covers or mosquito netting work
very well for early-season protection. This will also protect your plants from other pests like fruit flies
and caterpillars. Sometimes exclusion is a lot of work initially but saves heaps of effort over time.
- The colour yellow is meant to be attractive to grasshoppers, so there are various ways this can be used to
trap grasshoppers. Long sticky tape traps are commercially available. Dams, ponds or children’s paddling pools,
can be used to drown grasshoppers by floating pieces of yellow plastic in the water or suspending it from bamboo
just above the water. Fish will happily eat the grasshoppers or they could be collected and fed to chooks.
- Small traps can be made out of jars or buckets filled with water and a 10% molasses solution, cover with a
film of canola oil to deter bees and mosquitoes. Bury the containers up to their rim in the soil; clean and
renew the bait as needed.
- Canola oil has been found to be a grasshopper attractant, it could be used to make baits more attractive to
grasshoppers, combined with organic insecticides to make them more effective and floated as an oil on top of
- Insecticidal potassium soap sprays work best on small grasshoppers.
- Make up a garlic or chilli spray as a repellent.
Home Made Chilli Spray
Blend together half a cup of fresh chillies with 2 cups of water. Add a dash of dishwashing liquid to improve
sticking. If you have no chillies substitute with 2 tablespoons of Tabasco sauce. Always spray a small section
of the plant to check for leaf burn. Check in 24 hours and if there is no damage spray all the plants you want
to protect. Leaf burn with any spray is more likely to occur during hot weather.
Yellow Card Trap