If your tomato garden is being decimated by grasshoppers or locusts – what steps can you do to rid your plants of these awful pests?
The first thing to note is that nature will always lend a helping hand. Birds love grasshoppers and locusts; chickens also love them. Hence, if you keep chickens, it is often a good idea to place your vegetable garden alongside them to that they share as much boundary fence as possible. Other garden helpers are lizards, frogs, snakes, ants and assassin bugs. Parasitic and paper wasps as well as Robber flies also prey on grasshoppers.
It is a good idea to plant a perennial 'refuge' around your vegetable patch or tomato crop where these predatory insects can hide. Recommended refuge plant species are coriander, dill, anise, sweet Alice, clover and caraway.
When controlling grasshoppers, the first thing to do is to check whether the grasshoppers you are seeing are plant eating ones, or whether they are actually eating other pests in your plants; not all grasshoppers are plant eaters. Those that are predatory (eat other pests) generally have spiny front legs that are adapted to grabbing prey. In addition, there are 2 types of grasshopper: those which are large with long antennae (feelers, which are longer than the body) and those with short antennae. The grasshoppers with long antennae are often plant feeders and are usually nocturnal – feeding at night. Short 'horned' grasshoppers and locusts are active during the day.
To control plant eating grasshoppers and locusts, a number of options are available:
- Cover plants with a physical barrier such as a mosquito net
- Check plants early in the morning whilst it is still cool. As it takes a while for the grasshoppers to warm up, it is simple to catch them by hand or with a net.
- Traps can be made by burying a bucket up to the rim and filling it with a 10% molasses-water solution. Put canola oil on the surface to deter bees and mosquitoes. Renew as required. A soft pesticide can be mixed in with the canola oil.
- Use a chilli spray. To make it, blend half a cup of chillies with 2 cups of water and a drop of dishwashing liquid.
- Insecticidal potassium-based soap may work on the small or younger hoppers.
- Specific grasshopper biological insecticides are available in some countries such as the USA.