Hatching grasshopper that restricts feeding to grasses. In areas of the West Slope and around Steamboat Springs. The primary species present in recent outbreaks reported It tends to be most abundant in moist sites and is Hatches in late spring, a few weeks later than many grasshoppers.Ī widely distributed grasshopper that feeds on many Often the most common species damaging gardens, it migratesįrom empty lots, roadsides, and other undisturbed sites. Hatching species and capable of long migration flight. Often the most damaging species to croplands. Gardens and one of the largest in the genus Melanoplus. Often one of the first grasshoppers found moving into Primary grasshoppers that damage gardensĪnd small acreage pasture areas in Colorado Both the fungus disease and nematode parasite are favored by wet weather. A very large nematode ( Mermis nigriscens) also sometimes develops in grasshoppers. Stiff, dead grasshoppers found stuck to a grass stem or twig indicate infection with this disease. A fungus ( Entomophthora grylli) infects grasshoppers causing them to move upwards and cling to plants shortly before they kill the insect host. Grasshoppers are also subject to some unusual diseases. Grasshoppers are also frequently eaten by coyotes. Many birds, notably horned larks and kestrals, feed heavily on grasshoppers. Adult robber flies are common predators of grasshoppers during summer and other flies develop as internal parasites of grasshoppers. Many species of blister beetles (see fact sheet 5.524, Blister Beetles in Forage Crops) develop on grasshopper egg pods and blister beetle abundance cycles along with their grasshopper hosts. Some insects commonly feed on grasshoppers. However, very dry winter and spring conditions also can be harmful to survival since required tender new plant growth is not available. For example, cold, wet weather is very destructive to newly hatched grasshoppers. The most important factors are weather related, particularly around the time of egg hatch. A few species, perhaps most conspicuously the speckledwinged grasshopper, spend winter as a nymph, remain active during warm periods, and may develop to the adult form by late winter. Species that winter in the egg stage die out in late summer and early fall. Surviving grasshoppers continue to develop over the next several weeks, usually molting through five or six stages, before ultimately reaching the adult form.Īdult grasshoppers may live for months, interspersing feeding with mating and egg laying. Adverse weather or absence of suitable foods can cause high mortality. The first few days are critical to survival. At egg hatch the tiny first stage nymphs move to the surface and seek tender foliage on which to feed. For the majority of species the eggs hatch in mid- to late-spring, varying with soil temperatures. The egg stage is the overwintering stage of most, but not all, grasshoppers. Egg laying may be concentrated at certain sites with favorable soil texture, slope, and orientation, producing ‘egg beds.’ Relatively dry soils, undisturbed by tillage or irrigations, are preferred. Differential grasshopper.Īll grasshoppers lay their eggs in soil, in the form of tight clustered pods. Furthermore, grasshoppers may incidentally damage shelterbelt plantings when they rest on twigs and gnaw on bark, sometimes causing small branches to die back. However, during outbreak years even these may be damaged. Grasshoppers less commonly feed on leaves of trees and shrubs. Squash, peas, and tomatoes (leaves, not fruit) are among the plants that tend to be avoided. However, others will readily feed on garden and landscape plants (Table 1).Īmong vegetable crops certain plants are favored, such as lettuce, carrots, beans, sweet corn, and onions. Other grasshoppers restrict their feeding to plants of no great economic value and a few even feed primarily on weed species (e.g., snakeweed). Some primarily feed on grasses or sedges, while others prefer broadleaved plants. Over 100 species of grasshoppers occur in Colorado and their food habits vary. Problems tend to increase beginning in early summer and can persist until hard frosts. For many reasons, grasshopper populations fluctuate greatly from year to year, and may cause serious damage during periodic outbreaks. They also are among those most difficult to control, since they are highly mobile. Grasshoppers can be the most noticeable and damaging insects to yards and fields. During periods when local outbreaks are developing, control usually involves using sprays or baits. There are over 100 species of grasshoppers in Colorado.All grasshoppers lay their eggs in soil.Grasshoppers are the most difficult insect to control because they are highly mobile.
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