Grasshoppers and locusts
Several species of grasshoppers and locust feed on maize. The edible, a long horned grasshopper Homorocoryphus nitidulus vicinus (Ruspolia differens) has been reported to occasionally attack maize in Tanzania (Bohlen, 1973). This grasshopper attacks maize in the silking stage, arresting pollination. Other grasshoppers and locust attack maize from the mid-whorl stage to maturity, and may consume every part of the plants. Attacks vary in severity from location to location.
- Conserve natural enemies. Avoid destroying larvae of blister beetles, since they feed on eggs of grasshoppers. Other natural enemies include ants, parasitic flies, assassin bugs, predatory wasps, birds, lizards, snakes, frogs, and fungi. Robber flies are a major predator of grasshoppers.
- Domesticated poultry (e.g. chickens, turkeys, guinea fowl, geese, and ducks) and wild birds are good for keeping grasshopper populations in check. However, birds may damage the plants too. To avoid this enclose the birds in wire fencing along the perimeter so that they can prey on visiting grasshoppers while staying out of the crop.
- Ensure the ground is covered with crops, grass or mulch. This is reported to reduce grasshopper numbers since they prefer laying eggs on bare soil.
- Catch grasshoppers by hand or with a butterfly net. Catching them in the early morning is easier, as they are less active in the mornings.
- Dig or cultivate the land before planting to expose the eggs to predators and to the sun.
- Whenever necessary spray biopesticides. Neem extracts act as antifeedant (grasshoppers stop feeding when exposed to neem products) and affect development of grasshoppers. For more information on neem for control of grasshoppers link to section of grasshoppers in cassava datasheet. IITA (the International Institute of Tropical Agriculture) researchers and partners have developed an environmental friendly biopesticide "Green Muscle" based on a naturally occurring fungus strain indigenous to Africa (Metarhizium anisopliae). This fungus is deadly to locusts and grasshoppers but reportedly does not damage plants, animals- or people. Typically 70 to 100 percent mortality rates were obtained after 8 to 28 days of application. www.iita.org.