A locust’s life, from egg to death, typically spans three to five months, though the range stretches from as little as two months under hot conditions to more than half a year in cooler climates. That compact timeline packs in a surprising amount of biological drama: a dormant egg buried in soil, a wingless nymph that sheds its skin multiple times, and a winged adult capable of flying hundreds of kilometers. The specifics shift depending on species, temperature, food quality, and whether the locust is living a quiet solitary existence or caught up in a devastating swarm.
The Egg Stage
A female locust deposits her eggs in a pod buried several centimeters into moist soil. Depending on the species, each pod contains anywhere from about 20 to over 100 eggs glued together with a frothy secretion that hardens into a protective plug. The desert locust, the species responsible for some of the most destructive swarms in history, typically lays three to four pods in her lifetime, spacing them roughly two weeks apart.
Under warm, moist conditions, eggs hatch in about two weeks. But that timeline is extremely sensitive to the surrounding soil. Research on grasshopper and locust eggs in Inner Mongolian grasslands found that higher soil temperatures accelerated hatching by several days, while drought significantly delayed it. A soil temperature of 35°C advanced hatching by roughly three to six days depending on species compared to cooler soils, but when soil moisture dropped to just 2%, hatching was delayed and hatching rates fell.1Frontiers in Ecology and Evolution. Effects of Soil Temperature and Moisture on the Development and Survival of Grasshopper Eggs in Inner Mongolian Grasslands The combination of high heat and low moisture was the worst scenario, significantly reducing both egg survival and the proportion that successfully hatched.
In cooler or temperate regions, eggs can enter a state of dormancy called diapause, overwintering in the soil for months before hatching in spring. This effectively pauses the life-cycle clock. A locust egg laid in autumn might not produce a nymph until four or five months later, which is why the “three to five months” lifespan figure only captures the active portion of the cycle for species in warmer climates.
Nymphal Development
When a locust egg hatches, what emerges is not a larva but a nymph, a miniature version of the adult that lacks wings. The nymph goes through a series of growth stages called instars, molting its exoskeleton each time to accommodate a bigger body. Most locust species pass through five instars, though some individuals, particularly those reared in crowded conditions, go through six.
The entire nymphal period lasts roughly 30 to 40 days for desert locusts kept at typical warm-climate temperatures, but this stretches considerably in cooler environments. Each instar lasts about five to ten days, with the later instars taking longer as the nymph grows larger and more complex structures develop. Wing pads begin appearing around the third instar and become increasingly prominent, though the wings do not become functional until the final molt into adulthood.
Nymphs are voracious feeders. They need to accumulate enough reserves not just for daily survival but for the massive physiological investment of the final molt, which produces a fully winged adult roughly ten times heavier than the first-instar hatchling. Nutrition during this phase matters enormously. Locusts actively regulate their food choices to maintain a balanced protein-to-carbohydrate intake, and nymphs of the migratory locust prefer roughly a one-to-one ratio of protein to digestible carbohydrates. When their diet is deficient in an essential nutrient, they compensate by eating more, even if it means slower development.2ScienceDirect (Elsevier). Review: Nutrient requirements of migratory and desert locusts farmed for food or feed
Adult Life and Sexual Maturation
After the final molt, a newly emerged adult locust is soft-bodied and pale. It takes several days for the cuticle to harden and darken. But reaching physical adulthood is not the same as reaching reproductive maturity. Desert locusts need an additional maturation period before they can breed, and how long that takes depends heavily on temperature. Warmer conditions speed up both development and the time to sexual maturation, while cooler temperatures slow everything down.3Semantic Scholar. Effect of Temperature on Development, Sexual Maturation Time, Food Consumption and Body Weight of Schistocerca gregaria Forsk. (Orthoptera: Acrididae)
In desert locusts, sexual maturation is orchestrated by juvenile hormone. Males turn bright yellow as they mature, a visual signal that they are ready to mate. This color change, along with the production of a pheromone called phenylacetonitrile, is tightly controlled by specific hormone receptors. When researchers experimentally disrupted these receptors, males failed to turn yellow, could not perform mating behavior, and had dramatically reduced pheromone levels and smaller reproductive organs.4PubMed Central. Crucial Role of Juvenile Hormone Receptor Components Methoprene-Tolerant and Taiman in Sexual Maturation of Adult Male Desert Locusts For the locust, maturation is not just growing up; it is a hormonally gated switch that determines whether the animal can contribute to the next generation at all.
The Australian plague locust offers a contrasting timeline. Females of this species reach reproductive maturity in about 12 days, and populations show cyclic fluctuations in the frequency of gravid females, with successive egg-laying waves roughly every 12 days.5Australian Journal of Zoology. On the sexual maturation, breeding, and ovipsition behaviour of the Australian plague locust, Chortoicetes terminifera (Walk.) That rapid turnaround allows this species to squeeze in multiple generations during a single favorable season.
Adult locusts generally live two to four months after their final molt, though some individuals in cooler conditions or in laboratory settings survive longer. Females tend to outlive males, in part because males often die sooner after mating. The total lifespan from hatching to death for an adult desert locust under field conditions is typically in the range of three to five months, with the egg stage adding anywhere from two weeks to several months on top of that depending on whether diapause occurs.
How Solitarious and Gregarious Phases Affect the Life Cycle
What makes locusts so different from ordinary grasshoppers is phase polyphenism: the ability to switch between a solitary, cryptic form and a gregarious, swarming form. These are not different species but the same animal expressing radically different body plans, colors, and behaviors depending on how crowded its environment is. Crowding biases conversion toward the gregarious form.6PubMed Central. Locust dynamics: behavioral phase change and swarming The trigger is surprisingly specific. In desert locusts, the behavioral switch from solitarious to gregarious is initiated by repeated mechanical contact on the outer surface of the hind legs. Stimulating ten other body regions did not produce the same effect.7PubMed. Gregarious behavior in desert locusts is evoked by touching their back legs
Phase matters for lifespan. Gregarious locusts develop faster as nymphs, sometimes completing the nymphal period several days sooner than their solitarious counterparts. They also tend to be smaller-bodied but more metabolically active. This faster pace of life means gregarious adults often burn through their reproductive potential more quickly. Solitarious locusts, by contrast, develop more slowly, are larger and more cautious, and may live somewhat longer as individuals, though the difference varies by species and conditions.
The phase shift even reaches into the gut. Gut bacterial communities differ dramatically between solitary and gregarious migratory locusts. In gregarious individuals, the bacterium Serratia dominates the gut, averaging about 77% of the bacterial community, while in solitary locusts the gut is dominated instead by Klebsiella, at roughly 74%.8PubMed Central. Behavioural phase transitions in the migratory locust, Locusta migratoria, are related to changes in the gut bacterial composition Whether this gut reshuffling directly influences lifespan is still being investigated, but it underscores just how profoundly the phase transition reshapes the animal’s biology.
What Kills Locusts Before Old Age
In the wild, very few locusts die of old age. The list of natural enemies is long. Desert locusts face predation from bombardier beetles, parasitic flies, wasps, ants, mantises, spiders, lizards, finches, crows, snakes, frogs, and toads. Over 140 species of birds have been documented feeding on desert locust nymphs and adults. Different predators target different life stages: some beetle larvae and fly species parasitize eggs in the soil, reducing hatching rates, while birds and lizards focus on nymphs and adults above ground.9Journal of Integrative Agriculture. Review IPM – Biological and integrated management of desert locust
Disease is another major killer. Fungal pathogens in the genus Metarhizium are among the most studied biological control agents for locusts. These fungi attach spores to the locust’s cuticle, germinate, and eventually penetrate into the body cavity, colonizing the insect from the inside. The process from infection to death can take several days to a couple of weeks depending on conditions.10PubMed Central. Host-Pathogen Interactions between Metarhizium spp. and Locusts Researchers have been engineering more virulent strains. One study showed that a genetically modified strain of Metarhizium acridum, enhanced with an additional enzyme gene, significantly increased locust mortality and shortened lifespan compared to the wild-type fungus.11PubMed. Transformation of glycerate kinase (GLYK) into Metarhizium acridum increases virulence to locust
For eggs, the dangers are different. Soil-dwelling parasitoids of the genus Scelio specifically target locust eggs, while beetle larvae of the genus Mylabris consume them underground. Drought, flooding, and temperature extremes also destroy eggs in large numbers. The mortality rate from egg to adulthood in the wild is enormous; only a small fraction of eggs laid ever produce a breeding adult.
The Energy Cost of Swarming
Swarming is one of the most energetically demanding things a locust does, and it has real consequences for how long the animal survives. During long-distance migration, locusts burn through fat reserves at a punishing rate. Experimental work on migratory locusts showed that over three days of sustained tethered flight, locusts lost about 30% of their stored body lipid even when given 19 hours per day of access to high-quality food. They tried to compensate by increasing carbohydrate consumption by roughly 30%, but their intake and assimilation capacity simply could not keep pace with what flight demanded. Modeling suggested that locusts cannot sustain more than about one hour of daily flight without entering an energy deficit, even with unlimited food available.12PubMed. Energetic constraints on multi-day flights in migratory locusts
This means that real-world swarms, which have been tracked by aircraft for 10 to 30 days, require either substantial pre-migratory fattening or extended stopovers where locusts can feed for several days. Genomic analysis has revealed that locust genomes contain expanded families of genes related to energy metabolism and detoxification, consistent with the extraordinary demands of long-distance flight and the need to process large volumes of diverse plant material along the way.13PubMed Central. The locust genome provides insight into swarm formation and long-distance flight
For an individual locust, joining a swarm is a calculated metabolic gamble. The energy spent migrating comes at the expense of body reserves that would otherwise fuel reproduction and general maintenance. Locusts that exhaust their fat stores during migration without finding adequate feeding grounds will die before reproducing. In that sense, swarming can either extend the effective lifespan, by delivering the animal to fresh resources, or dramatically cut it short.
How Many Generations Per Year
A locust’s lifespan determines how many generations a population can fit into a single year, and this varies enormously by geography. The migratory locust provides a clear example. In northern regions with short summers, it completes just one generation per year. Farther south, where warm seasons are longer, populations shift to two or even three generations annually. Body size tracks these patterns: in the single-generation northern zone, locusts are larger toward the southern edge, but the trend reverses at the latitudes where the number of generations per year increases.14Journal of Orthoptera Research. Geographic variation in body size of the migratory locust Locusta migratoria (Orthoptera, Acrididae): Masaki’s cline and phase polyphenism Squeezing in an extra generation means each individual develops faster and ends up smaller.
Desert locusts in tropical and subtropical zones can produce two to three generations per year when conditions are favorable, with each generation completing its cycle in roughly three to four months. In the semi-arid regions where desert locusts breed most successfully, rainfall determines everything. A good rain triggers egg laying; if subsequent rains arrive while the first generation’s offspring are maturing, a second generation follows almost immediately. This cascading effect is what transforms a modest locust population into a continental-scale plague within a single year.
The Australian plague locust illustrates yet another strategy. Second-generation females, those born during the January-to-March summer period, lay more egg pods than first-generation females from the preceding spring.5Australian Journal of Zoology. On the sexual maturation, breeding, and ovipsition behaviour of the Australian plague locust, Chortoicetes terminifera (Walk.) This suggests that later generations, which develop under peak summer conditions, may invest more heavily in reproduction, even if that investment shortens their own lives.
Climate Change and the Locust Calendar
Rising global temperatures are already reshaping where and how often locusts can breed. Warmer conditions accelerate every temperature-dependent phase of the life cycle, from egg development to nymphal growth to adult maturation. The practical result is that populations in regions previously limited to one generation per year may begin producing two, and regions with two may see three.
Modeling work on the migratory locust projects that warming will expand suitable habitat into new regions, particularly in Europe, where the species has historically been a minor concern.15PubMed Central. Locusta migratoria (L.) (Orthoptera) in a warming world: unravelling the ecological consequences of climate change using GIS For agricultural communities in these newly suitable zones, the arrival of a locust species capable of phase-shifting into swarms represents a genuinely novel threat. And because warmer conditions speed up the life cycle, each invasion season could produce more generations and therefore more total locusts before winter shuts things down.
The relationship between climate and locust lifespan is not straightforward, though. Hotter temperatures shorten the life cycle but also increase metabolic costs and water loss. At extreme temperatures, egg survival drops sharply, nymphs die during molts, and adults burn through their energy reserves faster. The soil moisture findings from Inner Mongolia illustrate this tension: higher soil temperatures accelerated hatching, but combined with drought they actually reduced the proportion of eggs that survived.1Frontiers in Ecology and Evolution. Effects of Soil Temperature and Moisture on the Development and Survival of Grasshopper Eggs in Inner Mongolian Grasslands Climate change does not simply hand locusts a better deal; it reshuffles the deck in ways that create new windows of opportunity and new bottlenecks simultaneously.
Locusts Raised in Captivity
Laboratory-reared locusts typically live longer than their wild counterparts, for straightforward reasons: no predators, no parasites, consistent food, and controlled temperatures. Under standard lab conditions of around 30 to 32°C with ample food, adult desert locusts routinely survive three to four months, and some individuals reach five or six months. Females kept at lower temperatures and given high-quality diets occasionally live even longer.
This has practical implications for the growing industry of farming locusts for food and animal feed. Lifespan and generation time determine production schedules. Faster-growing, shorter-lived generations produce more harvestable biomass per year but require more frequent colony restocking. The nutritional balance of the feed matters too. Diets deficient in protein slow nymphal development and extend the time to harvest, while excess protein increases waste output through higher uric acid excretion.2ScienceDirect (Elsevier). Review: Nutrient requirements of migratory and desert locusts farmed for food or feed Getting the diet right is not just about nutrition; it is about controlling the pace of the life cycle itself.
Captive colonies also allow researchers to study lifespan in ways that field observation cannot. The hormonal controls on maturation, the effects of crowding density on development speed, and the precise caloric costs of flight have all been measured using lab-reared animals. Much of what we know about how long individual locusts live comes from these controlled settings, since tracking a single wild locust through its entire life cycle is essentially impossible.