A sudden increase in grasshoppers across your yard and garden can be unsettling. These insects, part of the suborder Caelifera, are common inhabitants, but their populations are usually low enough to go unnoticed. A surge is often the result of large-scale weather patterns converging with specific, localized conditions. The high numbers indicate that the environment has become uniquely favorable for their survival and reproduction.
Climatic Factors That Cause Population Explosions
Grasshopper populations are cyclical, and large-scale outbreaks are tied to sustained weather conditions over multiple seasons. Extended periods of warm, dry weather benefit grasshopper survival and reproduction. Drought conditions reduce soil moisture, which lowers the prevalence of fungal pathogens that naturally infect and kill grasshopper eggs and nymphs.
A mild winter followed by a warm, dry spring creates an ideal sequence for a population increase. The hard-cased egg pods, laid in the soil the previous fall, survive better without excessive moisture or cold stress. Warm spring temperatures then trigger an early and synchronized egg hatch, allowing a greater number of nymphs to emerge and begin feeding.
The drier environment also concentrates the available food supply, pushing young grasshoppers into closer proximity. Grasshopper outbreaks are most common in areas receiving less than 25 inches of annual rainfall, highlighting the importance of arid conditions. This dependence on dry conditions means that a localized population explosion often echoes regional weather patterns from the past year.
Specific Yard Conditions That Attract Grasshoppers
While regional climate sets the stage for a population boom, specific features of your yard act as a powerful magnet for high numbers of grasshoppers. Irrigated lawns and gardens become an “oasis” of lush, green vegetation when surrounding areas are dry. This abundant, moist forage is attractive to hungry grasshoppers seeking food and relief from heat.
Grasshoppers prefer areas that provide safe, undisturbed sites for egg-laying, which occurs in the late summer or fall. Untilled patches, such as weedy fence rows, field edges, or tall, neglected grass, are prime locations for females to deposit egg pods in the soil. These surrounding areas serve as a nursery, producing the next generation that migrates into cultivated spaces.
The presence of preferred food plants also acts as a strong attractant. Grasshoppers prefer tender, succulent plants, including lettuce, beans, sweet corn, and onions. The absence of natural enemies, such as certain birds, spiders, or parasitic wasps, can contribute to the high survival rate in a localized yard.
Understanding the Grasshopper Life Cycle
The current high numbers are directly related to the timing of the life cycle, which involves three stages: egg, nymph, and adult. Most pest species spend the winter as an egg pod buried beneath the soil surface, protected by a hard, frothy case. These eggs hatch in the spring, typically between April and June, depending on the accumulated heat units in the soil.
The initial surge in visible grasshoppers is often the nymph stage, which are smaller, wingless versions of the adults. Nymphs are voracious feeders and must molt five or six times over 35 to 50 days to reach maturity. During this rapid growth, they feed intensely, often remaining congregated near their hatching areas while food is plentiful.
The population peak is most noticeable in late spring through mid-summer as nymphs grow into larger, more mobile adults. Once they develop functional wings, adults can fly for miles, moving into yards from nearby fields when original food sources dry up or are harvested. A high number of adults means females, which can lay up to 300 eggs in a season, are preparing to deposit the next generation of eggs.
Potential Damage to Plants and Gardens
The high number of grasshoppers can translate into significant damage to ornamental plants and vegetable gardens. Grasshoppers are chewing insects, and their feeding leaves distinctive signs of injury. They create large, ragged holes and notches in plant foliage, often consuming the tissue between the leaf veins.
They target tender, new growth first, which means young plants and soft-leafed vegetables are at the highest risk. In severe infestations, grasshoppers can completely strip the leaves from plants, a process known as defoliation. This intense feeding can quickly destroy unprotected gardens and threaten the health of small trees and shrubs.
While most yard issues involve common species like the differential or redlegged grasshopper, these insects are sometimes confused with true locusts. Locusts are specific grasshopper species that change color and behavior under high population density to form massive, migratory swarms. However, the issue in a typical yard is almost always caused by non-swarming, localized species feeding heavily on cultivated plants.