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.

They are:

Differential grasshopper, Melanoplus differentialis

Black chevron markings on the hind femur help identify this species. Adults are 11⁄8 to 13⁄4 inches long. They move into fields from weedy borders and can be very destructive to crops. They are seldom found in grassland.

Red-legged grasshopper, Melanoplus femurrubrum

Adults are 7⁄8 to 11⁄4 inches long with red hind tibia. This species is especially damaging to alfalfa and other legumes, but they can be a problem in other crops, too. They are not a problem in grassland.

Migratory grasshopper, Melanoplus sanguinipes

This species is very destructive to both grasslands and cultivated crops. Adults are 7⁄8 to 11⁄8 inches long. These grasshoppers are strong fliers and may swarm over long distances.

Two-striped grasshopper, Melanoplus bivitattus

Adults are 13⁄4 inches long with two light stripes that extend from the eyes to the wing tips. They eat mostly weeds but will also move into cultivated crops.

Packard grasshopper, Melanoplus packardii

This species prefers sandy soils with light grass cover. They are the least damaging of the five species, but large numbers of them can be a problem in both grassland and cultivated crops. A sixth species is not as damaging. It is the:

Lubber grasshopper, Brachystola magna

The lubber grasshopper prefers weedy areas but can be a problem in crops also, especially cotton. It is seldom a problem in grasslands. Adults are 1 3/4 to 2 inches long. These grasshoppers are flightless and their limited mobility makes them less damaging than the top five species. Lubber grasshoppers will feed on dead insects, even their own kind, in certain situations.

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. Grasshoppers have a high reproductive capacity. The female lays an average of 200 eggs per season, and sometimes as many as 400 eggs. If favorable weather increases the number of eggs, nymphs and adults that survive, the grasshopper population may be dramatically larger the following year.

Biology

Grasshoppers deposit their eggs 1⁄2 to 2 inches below the soil surface in pod-like structures. Each egg pod consists of 20 to 120 elongated eggs cemented together. The whole mass is somewhat egg-shaped. Egg pods are very resistant to moisture and cold and easily survive the winter if the soil is not disturbed. Grasshoppers deposit eggs in fallow fields, ditches, fencerows, shelter belts and other weedy areas, as well as in crop fields, hay fields and alfalfa. Eggs begin hatching in late April or early May. Hatching peaks about mid-June and usually ends by late June. If spring weather is cool and extremely dry, hatching may be delayed and continue into July. Young grasshoppers are called nymphs. They look like adults but are smaller and have wing pads instead of wings. Nymphs go through five or six developmental stages and become adults in 40 to 60 days, depending on weather and food supplies. The adults of grasshopper species that damage crops become numerous in mid-July and deposit eggs from late July through fall. Usually only one generation of grasshoppers is produced each year.

Biological Control

Grasshoppers have many natural enemies that help control their populations. A fungus, Entomophthora grylli, often kills many grasshoppers when the weather is warm and humid. Infected grasshoppers strike a characteristic pose at the top of a plant or other object. The grasshopper grasps the plant in a death embrace with the front and middle legs, while the

hind legs are extended. It dies in this position. Fungal spores develop in and on the grasshopper’s body, then become airborne and infect other grasshoppers. Another natural enemy is a protozoan, Nosema locustae. Its spores have been incorporated with bran to make insecticide baits such as Semaspore®, Nolo Bait® or Grasshopper Attack®. These 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. Other natural enemies include nematodes called hairworms and insects that feed on grasshoppers, such as the larvae of blister beetles, bee flies, robber flies,

ground beetles, flesh flies and tangle-veined flies. Birds (quail, turkey, larks, etc.) and mammals also eat grasshoppers, but have little effect on large populations.

Monitoring Populations

Farmers and ranchers should start watching for grasshoppers early in the season and begin control measures while grasshoppers are still nymphs and still within the hatching sites (roadsides, fencerows, etc.). Treating grasshoppers early means 1) having to treat fewer acres and use less insecticide, 2) killing grasshoppers before they cause extensive crop damage, and 3) killing grasshoppers before they can fly, migrate and lay eggs. Also, smaller grasshoppers are

more susceptible to insecticides than larger ones. You can estimate the size of a grasshopper infestation by surveying 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.

^a Field ratings should be used for both rangelands and croplands.

When control is necessary, select a suitable insecticide from Tables 2, 3, 4 or 5. It may be necessary to apply insecticide several times to protect gardens, trees and crops, especially if weeds and grass have dried out or been eaten by grasshoppers.

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THE IMPORTANCE OF WATER FOR CATTLE

Water is the most important nutrient. An adequate supply of clean, fresh water is a critical component of maintaining healthy, productive cattle. At this time of year in Oklahoma, managing your cattle’s water supply is more important than ever. Water accounts for at least 50 percent of your cattle’s live weight. Water is required to transport nutrients through the blood, maintain cellular structure, regulate temperature, and much more. In order for livestock to maximize feed intake and production, they need daily access to palatable water of acceptable quality and quantity. Water is also critical for cattle dealing with stress. Insufficient water intake lowers cattle performance more dangerously than any other nutrient deficiency. Dehydration in cattle severely weakens the ability of the respiratory organs to resist and expel disease-causing organisms. As well, hearing and sight of cattle can be adversely affected by dehydration.

Knowledge of water requirements of cattle is necessary when designing water supply systems where the water supply may be limited, or the delivery system restricts access in times of heavy use. Although quite a bit of data is available on the water intake of growing and finishing cattle, little information is available in published literature for mature beef cows. OSU Cooperative Extension Fact Sheet ANSI-3299 is an excellent resource for information about water needs of beef cows.

Factors that influence the daily water intake requirements of cows include the following:

During warm months, the daily ambient temperature and humidity have dramatic effects on heat stress and water intake. The Cattle Comfort Index, available through the Oklahoma Mesonet can be used to monitor heat stress or cold stress in beef cattle. The Cattle Comfort Index is calculated using ambient temperature, humidity, wind speed, precipitation and sunlight. At temperatures above 40 degrees Fahrenheit increase water consumption linearly.

Milk produced by beef cows is about 88% water. Accordingly, lactation has a direct impact on the water requirements and water intake will increase for each pound of milk produced.

Dry matter content of feeds consumed. Water requirements can be met, to some extent, by the moisture content of feeds consumed. For example, cattle grazing young vegetative forage at 20 – 35% dry matter will meet a higher proportion of water needs than cattle grazing seeded or mature forage which is 75 – 90% dry matter.

Water intake is highly related to rumen volume and feed dry matter intake. Higher daily feed consumption is associated with greater rumen volume. Accordingly, greater mature weight is associated with higher rumen volume and dry matter feed intake. Therefore, for the purpose of the following water requirement estimates, the influence of cow size and rumen volume on water intake is addressed through the influence of feed dry matter intake. The estimates below assume that dry cows consume 2.2% of their body weight and lactating cows consume 2.7% of their body weight in dry matter when consuming an average to moderate quality forage.

Estimates of Total Daily Water Requirements of Beef Cows

Average Daily Temperature (Fahrenheit)

40 65 90

Cow Weight Milk Produced/Day Gallons Water/Day

1,100 lbs. 0 (dry cows) 8.2 10.8 13.4

1,100 lbs. 25 lbs. 12.8 15.4 17.9

1,300 lbs. 0 (dry cows) 9.2 11.8 14.3

1,300 lbs. 15 lbs. 12.2 14.8 17.4

1,300 lbs. 30 lbs. 14.5 17.1 19.7

1,500 lbs. 35 lbs. 16.3 18.8 21.4

These estimates are intended to represent total daily water consumption. Free water intake could be lower when cows are consuming feeds of high moisture content.

Key Points

For each 10 degrees increase in temperature above 40 degrees, cattle need about one gallon more water per day.

For each additional gallon of milk produced, cows will need an additional gallon of water per day.

High moisture feeds contribute to water intake. The dryer the feed consumed; the more drinking water required.