Grasshopper Control

Grasshoppers

Barriers
Predators
Traps and Sprays

"Whether you tend a garden or not, you are the gardener of your own being,
the seed of your destiny." The Findhorn Community

There are over 1,000 species of grasshoppers occurring in the US alone. Worldwide the numbers go over 23,000! They take on many different colors and sizes, but it is the unmistakable physical appearance of grasshoppers that is consistent. It is characteristic that some will fly and some will jump.

What is the difference between grasshoppers and locusts?
Grasshoppers that migrate have been given the classification of locust. Grasshoppers and locusts are of the family Locustidae. However "true" locusts will emigrate when they have multiplied to the point that they must move on to an area that is capable of sustaining their feeding needs. This behavior in not consistent nor does it run in cycles like grasshoppers. This why we hear of swarms of locusts infesting an area. Crickets and katydids are of the locust family. Katydids are mostly green in coloring and also identified by their piercing "song" katy-did-katy-didn't. We see from all this that the name grasshopper is a catch all phrase for this group of insects.

NOTE: The "17 year locust" is actually the cicada which is not related to grasshoppers. The 17 year name tag comes from the ability of some of these creatures to live for up to 17 years. The majority of this life is spent in the nymph stage, underground, feeding on tree roots. Cicadas are not considered a true bug. One noticeable difference with cicadas is the lack of the long hind legs used for jumping that we see in the locust family members. The male Cicadas have a pair of resonating organs that emit a high pitched droning sound. For any of us who have actually been through a cicada infestation the memory of their "shells" hanging in the tree and lying on the ground is a haunting image.

Locusts emigrate by leaving one area to settle down in another with no predictability.
Grasshoppers, locusts, cicada, what have you...they are all extremely destructive.

The grasshopper control methods listed on this page can be tried when dealing with any member of the family Locustidae.

Name	Family	Characteristics	Hosts
Short Horned Grasshopper & Locust	Acrididae	Antennae are short, horn shaped & half the body length. Length is from 1/2 to 3 1/8 inch long.	They feed on all crops. Eggs are laid below the soil surface.
Long Horned Grasshopper & Katydid	Tettigoniidae	Antannae are quite long, bodies are from 1/2 to 3 inch in length. Hoppers are from dark brown to shades of green Katydids are generally green.	Eggs are inserted into plant tissue. They feed on tree and shrub foliage
Camel Cricket	Gryllacrididae	Tan or gray bodies with humped backs. Most have no wings and range from 3/8 to 2 inches long. They are all nocturnal.	Food preference is fungi, roots, leaves, dead bugs. Single eggs are laid in soil in caves, basements, under rocks and bark.
True Cricket	Gryllidae	Similar in appearance to long horn grasshoppers but only 3/8 to 1 inch long and forewings are shorter. Their chirping is higher pitched then hoppers.	Depending on which variety of cricket they feed on seeds, seedlings, small fruit, food crumbs and dead insects. Eggs are laid in soil or leaf tissue.
Cicadas	Cicadidae	Membranous wings, body length from 1 to 2 3/8 inches long. Markings go from black, brown, green to yellow. Eyes are bulging. They are quite ugly. They do not jump. Their songs range from a loud buzz to a clacking sound depending on species.	Generally the nymphs feed on tree root sap so they are sap suckers. Eggs are laid in tree branch crevices. The nymphs then burrow into the soil to feed on roots. The adults are not known to eat!

Grasshopper infestations vary in their intensity from year to year. Generally speaking seasons that have large populations will occur for two to four years simultaneously. After this cycle a period of low infestation will happen for three to four years. The cycles often repeat in this manner. Adults live for approximately 60 to 90 days.

Grasshoppers usually begin to hatch in mid spring. The warmer and drier the spring the earlier hatching will occur and the better the nymphs will thrive . Often times a late spring freeze will disrupt the cycle, killing the young hoppers. An early spring followed by cloudy, damp weather encourages diseases that sicken and kill them. Long, hot summers provide a bountiful food supply for them. This encourages early maturing of grasshoppers and an extended long egg-laying period. Cool summer and early fall conditions slow down grasshopper maturity resulting a reduced time period for laying eggs.

There are three stages of development for grasshoppers: egg, nymph (young adult) and adult hopper. The nymph stage goes through five instars (instar means development stages.) As each instar is completed they molt and become larger. It is in the first to the third week of reaching the adult stage that female hoppers will begin to lay eggs. They lay them in the soil covering them with a foamy like liquid which forms a hard, protective shell enabling them to withstand severe cold.

It is the during the nymph stage of hoppers that you want to take control action. Even in periods of low populations grasshoppers can cause considerable damage in home gardens. The main damage that hoppers inflict on plants are the consumption of foliage. During periods of overpopulation they can and will go after shrubs and tree, just about anything. Following are some methods to help you control grasshopper outbreaks.

Predators

Blister beetle and ground beetle larvae attack the egg pods of grasshoppers. They are both capable of consuming between 50 to 60% of grasshopper egg pods.

Snakes, toads, cats and skunks feast on hoppers.

Bird predators include bluebirds, brown thrashers, crows, hawks, mockingbirds, meadowlarks and sparrows.

Horse-hair worm, a large nematode up to several inches in length parasitizes and kills hoppers.

Robber flies and spiders will feed on grasshoppers.

Field mice and many types of rodents will dig up and eat the egg pods. They also feed on the adults.

Chickens, ducks and Guinea hens are prolific consumers of hoppers. Muscovy ducks are tops!

Preying mantis love to eat grasshoppers!
Fish: One of our visitors reminded us how fish love to dine on hoppers! He goes on to add that live hoppers make excellent fish bait and that the bigger the hopper the bigger the fish you can catch. Bass are extremely fond of them.

Barriers

Plant the herb horehound (Marrubium vulgare) which is known to repel grasshoppers.

Grasshoppers do not like cilantro which is used by many organic gardeners as a barrier crop.

Plant calendula as a barrier deterrent.

Spray a heavy infusion of garlic oil as a repellent.
Grasshoppers are attracted to monocultures and do not like nitrogen-fixing crops like peas and sweet clover.
Row covers, like Reemay, or screens can be effectively used to keep them from your crops.

Garlic Oil Spray
To make: Combine 3 ounces of minced garlic cloves with 1 ounce of mineral oil. Let soak for 24 hours or longer. Strain.
Next mix 1 teaspoon of fish emulsion with 16 ounces of water. Add 1 tablespoon of castile soap to this.
Now slowly combine the fish emulsion water with the garlic oil. Kept in a sealed glass container this mixture will stay viable for several months. To use: Mix 2 tablespoons of garlic oil with 1 pint of water and spray.

Traps and Sprays

Nosema locustae is a one celled parasite that infects and kills the hoppers when they ingest it. A single treatment can last for several years. Hoppers being of a cannibalistic nature will eat the dead parasite infected bodies. This sets in force a chain reaction passing the parasite from generation to generation. Certain species of hoppers may expire within several hours after treatment whereas others may take 4-6 weeks to be affected. Nosema locustae can be purchased at local nurseries and through many mail order sources.

It is generally sold already mixed with branmeal or you can mix it with branmeal yourself to entice the hoppers. Apply Nosema locustae as soon as hoppers begin to hatch. You definitely want to treat by the time they hit the third or fourth instar stage. It has little effect past these stages and on adults.
Apply at a rate of 1-2 pounds per acre. You can make a second application after 4 weeks.

Sink glass jars into the soil. Fill to the halfway point wit a mixture of 10 parts water to 1 part of molasses. The hoppers are drawn to the sweet smell of the molasses, they dive in and drown. Clean traps as needed.

Try a caffeine spray. Brew coffee 5 to 10 times stronger. Cool and spray as is.

Try a pepper spray using jalapenos, habaneros or any HOT pepper to repel the adults. Include some castile soap in with this.

Spray insecticidal soap mixed with beneficial nematodes directly on grasshoppers in the evening.

Diatomaceous earth applied as a dust can be an effective control. DE has razor sharp edges that penetrate the hoppers exoskeleton, dehydrating them and killing them. The same effect is had internally as they will also eat DE. Be sure to wear a mask when working with DE, you do not want to inhale it!
Gardeners can use organic botanical products like pyrethrin to knock down nymphs in the first or second instar.

A word on Diatomaceous earth: 30 million years ago, silica shells of one-celled algae (diatoms) built up on the ocean bottoms forming deep deposits called diatomite. These fossilized shells are mined and milled they produce the razor sharp shards of silica, a desiccant.
DE looks and feels like talcum powder; but to an insect it is a lethal dust that scratches and absorbs the wax coating on the insects' surface, leaving it to die from dehydration. DE will eventually kill any insect that is exposed to it and will kill earthworms. DE does not break down in the environment, so it remains effective until it is washed away or turned into the soil. It is non-toxic to mammals, but will irritate the mucous membranes!
DE has a high mineral content and will add these minerals to the soil, improving it.

Neem Oil: A controversial topic among organic gardeners: neem oil is not to be dismissed lightly. Made from the seed of the Neem (azadirachta indica) tree, a shade tree native to India. The active compound azadractin is extracted using water, alcohol or petroleum ether. Neem has been used for centuries in India to protect stored grains.

Neem has many different effects on insects. It acts as an insect antifeedant and repellant. It can stop or disrupt insect growth (IGR = insect growth regulator) and sterilizes some species. Also of interest Neem has now been classified as an ovicide, mildewcide and miticide. It has now been approved for use on food crops.

For grasshoppers it should work as an IGR on the nymph stages of hoppers however you must be judicious in your spray program to get good control. As far as the adult stage we have consistently found that any plant sprayed with neem was not eaten by the hoppers. They actually land on the plants, but have not been observed to eat them at all. Other studies indicate no antifeedant success when using neem.

Fall cultivating will help expose buried egg pods to the weather and helps to discourage laying.
Black Strap Molasses: combine 4 ounces of this with one quart of water. Spray directly on hoppers. This will clog their pores so they cannot breath resulting in their death.
Henbit: A tea made from this weed and used as a spray may have some possibilities to repel hoppers.

Leaving areas of tall grass uncut can help by giving hoppers food and a refuge. You can then use the treatment of your choice to get at them in the contained area.

Update: 06/17/10