I have been plagued with grasshoppers this year. They seem to be chewing
up everything in sight. Large grasshopper populations are common during
years when the spring is dry and the summer is long and hot.
The best time to get a handle on a grasshopper problem is in early summer
when the insects are still in a juvenile stage. Check areas of tall grass
or weeds where they like to breed and lay eggs. This is where you are most
likely to find young grasshoppers.
Your direct treatment strategy should be two-fold. For immediate results
spray them with an insecticidal soap. Next, sprinkle the area with bait
called Nosema locustae, which is a microscopic organism that infects
grasshoppers with a disease. It’s usually mixed with bran meal. The
grasshoppers eat the bran meal, become infected and eventually die. The
disease is passed on to new generations as well. While this treatment may
take a while, it has a long-term impact. Both the insecticidal soap and
Nosema locustae are safe for you and your pets. Nosema locustae is
available commercially under the brand name of Semaspor.
There are some indirect solutions you can try as well. If you have the
space, allow the grass to grow in one area of your garden. The
grasshoppers will congregate there and thus be easier to treat.
In late summer and early fall, turn the soil in spots where you think
grasshoppers might be breeding. This will expose and destroy eggs that
will hatch next spring. Again, look for those weedy or grassy areas.
Chicken, guineas, praying mantis and cats are all grasshopper predators.
Sprinkle the ground around your roses with diatomaceous earth. This dust
is actually tiny algae fossils that cut into the grasshoppers’ exoskeleton
causing them to dehydrate.
There are also ways you can repel grasshoppers. Try planting calendula and
cilantro to drive them away or spray your roses with a garlic spray or ahot pepper spray.