Grasshoppers by Charles Bohmfalk
Grasshoppers are among the most widespread and damaging pests in Texas. There are about 150 species of grasshoppers in the state, but 90 percent of the damage to crops, gardens, trees and shrubs is caused by just five species.
Grasshoppers cause some damage every year, but they become very destructive during outbreaks. The main factor affecting grasshopper populations is weather. Outbreaks, or exceptionally large populations, are usually preceded by several years of hot, dry summers and warm autumns. Dry weather increases the survival of nymphs and adults. Warm autumns allow grasshoppers more time to feed and lay eggs. The last several fall seasons were warm and dry, so this year may be especially bad for grasshoppers again in Hunt county and much of the state.
Grasshoppers have many natural enemies that help control their populations. A fungus often kills many grasshoppers when the weather is warm and humid. Another natural enemy is Nosema locustae. Its spores have been incorporated with bran to make insecticide baits. Baits kill some nymphs but almost no adults, though infected adults lay fewer eggs. Baits act too slowly and kill too few grasshoppers to be useful for immediate control.
One way to control grasshopper populations is to eliminate sites where they might deposit eggs. Grasshoppers prefer undisturbed areas for egg laying, so tilling cropland in mid- to late summer discourages females. Tilling may reduce soil moisture and contribute to erosion, but those disadvantages must be weighed against potential grasshopper damage to the next crop.
Controlling summer weeds in fallow fields has two benefits: 1) Reducing the food supply for nymphs. 2) Reducing the food supply for egg-laying adults.
The following website contains more detailed information on control of grasshoppers and baits: Grasshoppers and Their Control
The website lists many control products and how to use them. Always read and follow manufacturer’s directions.