By Kathy Feagan
Across the globe, there are 11,000 species of grasshoppers. Grasshoppers and locusts have a row of pegs resembling a comb on their back legs. They scape the pegs against their front wings to make sounds. Last year, Texas had a huge population of grasshoppers due to our drought conditions, in which grasshopper thrive. Hot weather allows them to thrive easily through their mating and growth cycles as wet conditions lower the survival rate of their eggs and nymphs. Less than 25-30” of rainfall per year produces way too many grasshoppers. In the heat of June and July, huge grasshopper populations emerge. Their metabolisms speed up when it is hot and dry and they grow bigger, and eat a lot more. Their ability to cover large areas with their strong wings and to feed voraciously also helps them survive.
Differential, Packard, Red-legged, Migratory and Two-striped grasshoppers cause most of the damage to rangelands, gardens and crops and, during severe outbreaks, they cause major damage. It is estimated that 30 pounds of grasshoppers can eat as much as a full-grown steer and grasshoppers can eat 50 to 100% of their body weight each day. Texas A&M Entomology experts are continuously researching methods to control grasshopper populations and mitigate their damage.
Unfortunately, grasshoppers have high reproductive rates. Females lay from around 200, and sometimes up to 400, eggs per season when favorable weather increases their laying ability as well as the ability for nymphs and adults to survive. The eggs are laid ½ to 2” below the soil in pods filled with 20 to 130 elongated eggs. The egg pods are resistant to cold and moisture and are able to survive winter if the soil is left undisturbed. Grasshopper eggs are usually laid in late summer and fall in rural areas, along ditches, fencerows, in harvested crop areas, weedy fields, forage areas and pastures such as hay and alfalfa fields. Their eggs begin hatching in late April to early May and peak in mid-June. If the spring is cool and dry, hatching may be delayed into July. Each generation takes 40 to 60 days to complete, and most grasshoppers produce one to three generations every year. However, cool, dry weather in the spring and the hatching of different species can produce what seems like a constant population of grasshoppers throughout the summer and fall. The hatched grasshoppers are nymphs who look like adults but are smaller and wingless. Nymphs go through 5 to 6 instars, growing larger and finally producing wings as they reach adulthood. When threatened, they release a kind of grasshopper spit (called tobacco juice) that is made up of saliva, partially digested plants and digestion enzymes. This “tobacco juice” is very smelly, acidic and distasteful.
Heavy spring rains can reduce their populations by drowning nymphs and cool, wet weather can bring insect diseases and a fungus, Entomophthora grylli, often kills many grasshoppers when the weather is warm and humid, which reduce the population. The fungal spores develop on the grasshopper’s body and then become airborne and infect others. Another natural enemy is Nosema locustae, a protozoan, which can also be purchased to use on grasshoppers. Nematodes (tiny roundworms) lay their eggs on plants and when the grasshoppers eat them they feed inside the grasshopper’s body and can injure and slow them down and even eventually kill them.
According to Texas A&M AgrifLife, testing has shown that insecticides containing Bifenthrin Permethrin, and lamna-cyhalothrin work the best to kill and control grasshoppers with the longest residual control. For shorter control, try chlorpyrifos, diazinon or carbaryl. Vegetable gardens can be protected with geotextile fabric covers. But during heavy infestations, even these barriers can be destroyed by grasshoppers and spraying insecticides on the crop covers will help deter them. For biological and organic insecticides, Texas A&M AgriLife recommends Protozoans (Npsema locustae) safe for most beneficials, Purethrins (will kill beneficials) and Spinosad, safe for most beneficials.
Keep in mind that using pesticides will kill beneficial pollinators along with the grasshoppers. There are a few alternatives to consider.
One method to dissuade grasshoppers is to avoid planting their preferred plants. Grasshoppers are highly attracted to Althea, Amaryllis, Bush Honeysuckle, Butterfly Bush, Canna Lily, Cherry Laurel, Day Lily, Elaeagnus, Hardy Hibiscus, Iris, Liriope, Mondo grass, Mums, Nellie R Stevens Holly, Peach trees, Photinia, Privet, Purple Loosestrife, Roses, Tradescantia (Spiderwort), Weigela, and Wisteria. They are somewhat less attracted to Flowering Almond, Hardy Aster and Grapes.
If you really want to keep them out of your garden, you could plant lots of the plants they highly dislike: American Beautyberry, Artemisia, Bridal Wreath Spirea, Confederate Jasmine, Coralberry, Crape Myrtle, Dwarf Yaupon, Dwarf Burning Bush, Dwarf Mexican Petunia, Dianthus, Euonymus, Forsythia, Garlic, Juniper, Lantana, Mexican Bush Sage, Moss Rose, Nandina, Passionvine, Thrift, Persian Lilac, Penstemon, Purslane, Pygmy Barberry, Rock Rose, Salvia Greggii, Turk’s Cap, Verbena and Vitex.
You can also consider growing a “trap-crop” of tall grass or green plants around your garden. The trap will attract grasshoppers to eat them instead of your gardens. Attracting birds with bird feeders will help as they are natural predators along with blister beetle larvae, bee flies, wasps, robber flies, hairworms, tachinid flies, spiders, flesh flies, tangle-veined flies and ground beetles. Another suggestion is to keep chickens, guinea hens and turkeys who love to eat grasshoppers and will also fertilize your gardens.
Neem Oil is a good natural method to deter and slow the grasshoppers’ activity. Mix ½ teaspoon of castile or any mild liquid soap with 2 quarts warm water. Stir and add 3 teaspoons of pure neem oil, pour into spray bottles and spray your plants and soil. You can also set traps by setting a clear pane of glass atop a bucket of soapy water – when the grasshoppers fly into the glass, they fall down into the soapy water, sink and die. Sticky traps are also helpful.
Another method is to make a spray of Kaolin clay (available at craft stores). Mix in a pump-up sprayer: 2-1/2 cups of clay to a gallon of water plus a teaspoon of mild soap as a surfactant. You will need to constantly shake the sprayer while lightly spraying a light film of powder on leaves. This mixture gums up the grasshopper’s mouth so it can’t eat. The spray is also said to protect leaves from the hot sun. Unfortunately, it will wash off in rain or when watering and has to be reapplied often.
For big outbreaks (more than 8 grasshoppers per square yard), use biological bait controls (baits) like Nosema locustae (No-Bait and Semaphore) which are safe for organic production. It must be applied early each season where eggs are laid so, when nymphs hatch in spring, they are infected and eventually killed. It is only effective on the nymphs of most grasshopper species. You can also try Garlic Barrier AG+ which can be applied throughout the growing season to help deter pests from fields, gardens and pastures.
According to Texas AgriLife Extension, There are a number of grasshopper species common in Texas, including:
– Differential Grasshopper, Melanoplus differentialis, are probably going to be the first grasshopper to invade your gardens this spring. Theyare brown to olive green and yellow to nearly black and grow up to 1-3/4” long. They have very large hind legs (femora) which enable them to jump long distances. Their hind legs have chevron like black markings. They winter in egg stage in cold climates but some adults overwinter in very mild climates. They live in grasslands, open woods, wet crop areas and any lush vegetation and live in large groups. Nymphs tend to stay in the area where they hatched until their third instar. At this point, they crawl or hop to their food sources of alfalfa and wheat. The nymphs move in one direction in a large band towards their food sources. As adults, they can fly long distances in search of food. They eat many kinds of plants including crops, fruit trees, grasses and forbs. They eat corn, alfalfa, soybean, wheat and barley along with ragweed, sunflowers and prickly lettuce. They are often preyed upon by thread-waisted wasps, tiger beetles, soldier beetles and blister beetles, flies (robber flies and bee flies), birds and field crickets
– Redlegged grasshopper, Melanoplus femurrubrum, adults are 3/4 to 1-1/2” long and have bright red, herringboned patterned hind legs. This short-horned grasshopper’s back is reddish-brown with a yellow belly. This grasshopper is one of the last to hatch each year. They overwinter as eggs in soil and hatch in spring and early summer. Nymphs feed and grow through 5 instars for about 30 days to become mature grasshoppers. They prefer low, moist soils. They are very attracted to alfalfa and legumes. They can fly for up to 40 feet, about a yard above vegetation. When food sources are sparse, they can develop longer wings to fly rapidly to find more food sources. They are considered a crop pest damaging grains, grasses, alfalfa, soybeans and vegetables. Both adults and nymphs prefer grasses, legumes, dandelions, vetches, goldenrods and ragweed. They are hosts for poultry tapeworms and parasites and can infect the wild game birds and domestic fowl who eat them.
– Bigheaded grasshopper, Aulocara elliotti, eggs undergo embryonic development in summer, entering dormancy to overwinter. In early spring, the eggs hatch into nymphs. Adults begin laying eggs when they are 12-20 days old. They are over ½” to nearly 1” with large heads, slanted faces, with a gray body, spotted forewings and dark markings with blue hind tibias. Adults are active until the first frost and feed mostly on sedges and grasses. They can develop in large populations of 20 per square yard in grasses and up to 40 per square yard in desert grasslands. They can destroy grazing rangelands and sometimes lay the land bare. They not only eat grass forage but also cut it down and feed on the ground. They feed on sedges and 22 species of grasses.
– Lubber Grasshopper, Brachystola magna, can grow up to 2-1/2” long. They have small wings, tegmina, which makes them unable to fly. They are brownish-red with green to brown markings with red and black spots on their wings. They have a row of light dots on each abdominal segment. Females lay eggs in the ground in pods of up to 20 eggs. Wingless nymphs hatch in late spring to early summer and develop through 5 molts, or instars, becoming adults from summer to fall. Their main food are plants in the forb family (blanket flowers, ragweed, cotton, sunflowers, feverfew and lettuce). They also eat live and dead insects and you will find them in weedy areas along roadsides, open fields and areas with rocky soil. They are not considered to be pests of the grasslands they prefer.
– Packard Grasshopper, Melamoplus packardii, are spur throated grasshoppers. They are mostly a rangeland species and can be found in grasses and desert prairies. They prefer abundant vegetation like grasses, crops and forbs. They will also feed on ground litter like dead arthropods. They have adapted to crop and rural areas like cultivated fields, roadsides, fence rows, and uncultivated or abandoned farm lands. Some years they do develop large populations and cause damage to alfalfa and grains. The further south they are, the less damage they cause. They are a medium sized ½ to 1” long, green to brown in color, which helps them camouflage. They have a dark stripe across the top of the head, bordered by a pale yellow stripe, to their posterior. They have long wings that are speckled with spots that enable them to fly 30 to 60’. They shelter on the ground at night under grasses and forbs.
– Twostriped Grasshopper, Melanoplus bivittatus, are large, 1-1/3 to 2-1/4”, with a pair of pale yellow stripes on the top of the body (from eyes to hind tip wings). They are usually a yellowish-green coloration, resulting from carotenoids and chromoprotein which are synthesized by the plants they consume . During winter, their eggs are laid and hatch late April to early May. They have long hours of mating with some copulations lasting up to 9-10 hours while food and sperm are injected into females. This is productive for stronger sperm and transfer of nutrients. Once the female has mated, they usually become receptive to re-mating within 4 to 20 days. They eat weeds, grains, barley, wheat, corn, and lentil crops but, when food is scarce, can eat each other. They tend to eat the flowers, sepals and pods of plants preventing the plants from regenerating meaning they can become a major crop pest. Nymphs are attracted to forbs (broad-leaf plants) which help them survive and grow faster. A population of 10 adults per square yard can destroy and defoliate the entire crop. They waste as much as 6 times as much foliage as they eat. In gardens, they attack flowers and vegetables.
– Migratory Grasshopper, Melanoplus sanguinipes, are considered one of the most common and most destructive grasshoppers here in Texas. They grow up to 1-3/4” long and are usually green and yellow but some are black. They tend to not only fly long distances, but also swarm, making them very hard to control. They are found in grasslands, agriculture fields, weedy areas, especially around the edges pf crops, and meadows. They will eat many plants including mustards, ragweed, grasses and dandelions. It is also a very adaptable grasshopper, populating the entire continental U.S. and Canada.
If you have any gardening questions, call the Taylor County Extension Office at 325-672-6048 or email us at mgardeners@yahoo.com. We hope you visit bcmgtx.org for information on all Big Country Master Gardener events, like us on BCMGA Facebook, and check out training presentations on BCMGA YouTube. We are here to help you.
