Despite the heavy rainfall this spring in Texomaland, we are also witnessing an overabundance of grasshopper nymphs. Those of us who farm, garden, and ranch loathe seeing the copious amounts of mostly green baby grasshoppers by May. Texas A&M Agrilife cites 150 species in Texas and Oklahoma.

The United States Department of Agriculture (USDA) reports that over 400 grasshopper species dwell in North America. There are over 11,000 species worldwide. Grasshoppers date back to the early Triassic period from 251.9 to 201.3 million years ago. Grasshoppers survive on every continent but Antarctica.

Why Do We See So Many Baby Grasshoppers in Spring 2024?

Texomaland has witnessed a wet and soggy spring, and grasshopper populations increase in hot, dry spring climates, we are seeing a bumper crop of nymphal grasshoppers this year. We had an extreme freeze in winter 2024, but 2023’s drought could be the culprit, even though it has been a rainy but warm spring. 

Agriculture (Ag) news media is predicting that grasshoppers will reach high populations in 2024 and especially in Montana, Nebraska, and Colorado. Hot, warm, and dry weather allows grasshoppers to cycle through their growth cycle, mate, and lay eggs. The timing of rainfall can significantly lower the survival rate of eggs and nymphs in a given area. 

Areas that receive less than 30-inches of annual rainfall produce a grasshopper threat. A long, warm autumn contributes to more grasshoppers laying eggs. In spring, they can hatch and mature two to four weeks earlier in warm, dry climates. In June and July, large grasshopper populations emerge. Their metabolism speeds up in hot weather so they grow bigger and eat more. They do not nest or have territories.

The five grasshopper species of the differential, migratory, Packard, red-legged, and two-striped grasshoppers cause 90% of grasshopper damage to crops, rangeland, and urban gardens. During severe grasshopper outbreaks, they cause major damage.

Pest grasshopper species will devour grasses and broadleaved plants. They start life near their hatching area, and when their food runs out, they go on the move. Nymphs do not have wings and hop to find food. Mature grasshoppers can fly for miles in search of food.  

How Much Do Grasshoppers Eat?

It is hard to believe that 30 pounds of grasshoppers can eat as much as a 600-pound steer. Some Ag sources claim that grasshoppers eat 50% of their body weight daily. Grasshoppers have a sweet tooth and favor honeydew melons, nectar, other sugary fruits, and sugary vegetables. The University of Nebraska-Lincoln Extension cites,

“Estimates of daily dry matter intake for grasshoppers range from 30% to 250% of their body weight compared to 1.5% to 2.5% for beef cattle. A 1,250-pound cow would therefore consume 19 to 31-pounds of herbage each day. The same amount of herbage could be consumed by 8 to 104-pounds of grasshoppers.”

Grasshoppers, Bacteria, and Fungi

One natural enemy is the zygote fungus, Entomophthora grylli. It kills grasshoppers when the weather is warm and humid. Called summit disease, this fungus becomes inactive when it is hot and dry.

Dry weather results in larger populations of grasshopper eggs surviving Other grasshopper-killing fungi are Beauveria bassiana-worldwide, Metarhizium anisopliae-tropical regions, Metarhizium flavoviride-temperate regions, and Sorosporella sp-subtropical regions.

A female grasshopper can lay between 7 and 30 egg pods during the summer and fall. Each grasshopper pod contains 8 to 30 eggs. She lays about 100 eggs per year. Some species can lay up to 150 eggs per pod and others only 40.

The bacterium, bacillus thuringiensis (BT), thrives in soil. Heavy rains splash it up onto plant leaves. Grasshoppers and other insects eat the infected leaves, which cause paralysis of their guts and death. BT migrates deeper into soil in dry, arid climates to absorb the moisture it needs to survive.

Most of us have seen the characteristic pose of a deceased, infected grasshopper at the top of plants and objects. It grasps the plant in a death clutch with its front and middle legs, with extended hind legs.

Research Entomologist David Branson, USDA, Agricultural Research Service, reported, “We’re researching how controlled burns of rangeland areas can be used to manage grasshopper populations, either through changing food availability or mortality of grasshoppers and unhatched eggs.” 

What Is the Difference Between Grasshoppers and Locusts?

Grasshoppers and locusts belong to the same insect order, Orthoptera. Locusts and grasshoppers are variants of the same insect. All locusts are grasshoppers, but not all grasshoppers are locusts.

Entomologists distinguish locusts by shared behavioral characteristics, not physical characteristics. Locust appearances vary from species to species. The primary difference between locusts and grasshoppers is that locusts swarm. 

Locusts perform two interconvertible behavioral phases, solitarious and gregarious. When locusts enter a gregarious behavioral state, they swarm. Other grasshopper species do not have this ability and live in a solitarious phase, or alone, unless mating.

Locust Swarms in the U.S.

We do not see swarms in the U.S. these days. The famous 1873-1877 Rocky Mountain swarms attacked the Great Plains. They estimated this swarm was twice the square mileage of the state of Colorado, with trillions of locusts. The Rocky Mountain locust plagued American farmers from California to Texas to Minnesota.

About the Rocky Mountain Swarms, Laura Ingalls Wilder wrote in On the Banks of Plum Creek (1937), “The Cloud was hailing grasshoppers. The cloud was grasshoppers. Their bodies hid the sun and made darkness. Their thin, large wings gleamed and glittered. The rasping whirring of their wings filled the whole air, and they hit the ground and the house with the noise of a hailstorm.”

In the 1930s, the July 26, 1931, swarm was reported as so thick that it blocked out the sun. The grasshoppers ate cornstalks to the ground and left fields completely barren. The U.S. has not seen swarms since the early 1930s. Canada reported the last seen Rocky Mountain locust in 1902, and they are thought to be extinct.

Grasshopper Infestation Ratings

From Bosque County Texas A&M Agrilife Extension:

“You can estimate the size of a grasshopper infestation by surveying for nymphs or adults with the “square foot method.” Count the number of grasshoppers that hop or move within a square foot area. Then take 15 to 20 paces and sample another square foot area. Make 18 samples in all. Then add the numbers from each sample and divide the total by two to obtain the number of grasshoppers per square yard. If most grasshoppers you see are first to third instar (wingless and generally less than 1⁄2 inch long), divide the number by three to give the adult equivalent. Count fourth instar and older nymphs as adults.”

(As an insect grows, it sheds its rigid exoskeleton and replaces it with a larger one, or molting. The first instar is the stage after hatching from the egg, and the insect becomes subsequent instars after molting.)

Adult grasshopper infestation ratings based on numbers per square yard for rangeland and field crop locations: