Welcome to hopper hell! Because of our mild winter and excellent soil moisture conditions, survival of overwintering grasshopper eggs was very high. Our May rains added insult to injury by providing a smorgasbord of plants for hoppers to feed upon.
There are over 100 species of grasshoppers in Colorado, most with their own feeding habits. Some feed on grasses but most of our problem hoppers in this area feed on broadleaf plants. A few feed on weeds, but don't depend on them to clean up your weed problems while leaving your precious garden plants, shrubs and trees alone.
During outbreak years such as this year, considerable damage will be done to trees and shrubs that normally are pretty much ignored in most years. Certain plants are favored among vegetable crops including lettuce, carrots, beans, sweet corn and onions. Squash, peas, and tomatoes (leaves, not fruit) are among the plants that often are avoided.
Our most common grasshoppers are: differential grasshoppers, migratory grasshoppers, twostriped grasshoppers, redlegged grasshoppers and clearwinged grasshoppers. I am sure that "those damn grasshoppers" will suffice as a name for most people.
Certain areas are favored by grasshoppers for egg laying purposes. Grasshoppers lay their eggs in soil which is untilled and relatively dry. These overwintering eggs hatch in mid- to late spring, producing wingless immatures or nymphs. Over the next several weeks they will eat and continue to grow, molting about five times before becoming adults. While most adult grasshoppers are winged, there are some that are wingless and less mobile.
While there are predators of grasshoppers such as turkeys, other birds and even foxes and coyotes, don't count on them to solve your hopper problem. There are also diseases that can reduce their numbers but usually not enough during outbreak years.
Insecticidal control of grasshoppers is most effective when they are small and wingless. As they become winged, they can move considerable distances and reinfest areas previously sprayed where hoppers had been controlled. Insecticides that are effective as sprays include Sevin, Orthene and permethrin.
Baits can also be used. Bait formulations are made by mixing the insecticide, such as Sevin, with bran or some other carrier and kill grasshoppers that feed on the bait. Availability of commercial formulations of Sevin baits is often limited. Some folks resort to mixing up their own, even adding some molasses for added attraction.
Baits containing the protozoan Nosema locustae are a biological control option that may be considered for treating grasshopper breeding sites. There are some limitations to biological baits. Only young grasshoppers are susceptible, and it cannot be used effectively after adult migrations have occurred. It is also fairly slow acting and does not equally infect all grasshopper species. It is probably too late for this control method. Think about maybe trying it earlier next year.
I don't know about you but I've just about had it with these hopper invasions. Even my wild turkeys can't seem to eat enough of them to make a dent in their numbers. Oh well, I guess on the positive side, I can always grab a few hoppers as bait and go fishing!
Jim Leser retired to Cedaredge in 2007 after a career with Texas A&M University Extension in entomology. He is a member of the Cedaredge Tree Board and a Colorado Master Gardener.