Grasshoppers Mating: How They Find Mates & Reproduce

Grasshoppers find mates primarily through sound, producing species-specific songs by rubbing their hind legs against their forewings in a behavior called stridulation. But acoustic signals are only part of the story. Chemical cues on the body surface, visual leg displays, and even physical combat all play roles in bringing males and females together and determining who gets to reproduce. The whole process, from the first chirp to the burial of an egg pod underground, involves more complexity and more conflict than most people would guess from watching a grasshopper sitting quietly on a blade of grass.

Songs That Double as Species Filters

The calling song is the grasshopper’s primary long-range signal. Males of most species in the family Acrididae produce sound by scraping a row of tiny pegs on the inner surface of the hind femur against a thickened vein on the forewing. Each species has a distinct song pattern defined by the timing, rhythm, and frequency of its syllables and pauses. Females listen using tympanal organs on the sides of their abdomen, and they respond only to songs that match their species’ template. This selectivity keeps closely related species from wasting time and energy on cross-species encounters.

Female preferences are not just about recognizing the right species. Within a species, females favor certain song qualities over others. In the well-studied grasshopper Chorthippus biguttulus, researchers found that louder songs, a particular ratio of pauses to syllables, and shorter gaps within syllables all made males more attractive. Rhythm also mattered, but only in combination with gap duration. Together, these traits explained a substantial share of the variation in male attractiveness.¹ So female grasshoppers are not simply checking a box for “right species.” They are evaluating male quality through the fine structure of the song.

An interesting wrinkle is that grasshopper ears evolved before grasshopper songs did. Phylogenomic work on the order Orthoptera found that in the suborder Caelifera (which includes grasshoppers and locusts), abdominal tympanal ears first appeared in a non-sexual context and were only later co-opted for sexual signaling once sound-producing organs evolved.² In other words, grasshoppers could hear before they could sing. The ears likely started as predator-detection devices and were repurposed for mate finding over evolutionary time.

Chemical and Visual Signals Add Extra Layers

Sound carries well across a meadow, but once a male gets close to a potential mate, other senses take over. The waxy coating on an insect’s body, made up of compounds called cuticular hydrocarbons, carries chemical information about species identity and sex. Males of C. biguttulus and C. mollis respond to the chemical profile of females of their own species by launching into courtship song, but they ignore the chemical profiles of males or females of the wrong species.³ This means mate recognition is multimodal: a male needs both the right acoustic signal and the right chemical signature before he commits to courtship.

Research on the closely related species C. biguttulus and C. mollis has shown that chemical cues play a key role in keeping the two species reproductively isolated. Even where the species live side by side, their distinct cuticular hydrocarbon profiles help prevent hybridization.⁴ Without this chemical checkpoint, overlapping ranges could lead to much more interbreeding than actually occurs.

Some grasshopper species also use visual displays. Males of the band-winged grasshopper Chortophaga viridifasciata use their hind legs as semaphore-like signaling devices, waving them in patterns that are visible to nearby females.⁵ Other band-winged species flash brightly colored hindwings during short display flights, called crepitation, creating both a visual and auditory signal as their wings snap in the air. Not all grasshoppers use visual signals to the same degree, but in species that do, the combination of sight, sound, and smell creates a remarkably rich communication system for an insect brain to process.

When Males Fight for Access

Not all mating success comes down to song quality. In some species, males physically fight each other for access to females. Observations of the Australian alpine grasshopper Kosciuscola tristis documented serious combat involving biting, kicking with the powerful hind legs, mounting rivals, and grappling. Males became progressively more aggressive as the breeding season wore on, with the fiercest fighting occurring at the end of the season when mating opportunities were running out.⁶

In another study, researchers observed challengers swarming around a male-female pair, attacking the male guarding the female. Defenders kicked challengers away with their hind legs and flared their mandibles as a threat display, something challengers never did. Bites sometimes caused visible damage.⁷ These fights are not ritualized sparring matches. They are genuine contests with real physical costs, which makes sense given that the prize is direct reproductive access.

What Happens During Copulation

Once a pair forms, copulation in grasshoppers involves a physical locking mechanism. The male’s genitalia include specialized valves that interlock with structures in the female’s reproductive tract. In the lubber grasshopper Taeniopoda eques, the male attaches using this genital lock and then passes a series of small sperm packets called spermatophores. Each spermatophore is emptied of sperm, then extracted and replaced with a fresh one, all while the pair remains coupled. This arrangement allows the male to fully load the female’s sperm storage organ (the spermatheca) while maintaining a grip that prevents rival males from taking over.⁸

The internal anatomy involved is surprisingly elaborate. Correlative microscopy of a pair of Melanoplus rotundipennis grasshoppers frozen mid-copulation revealed numerous interlocking genitalic components in both sexes, the majority of which appear to be directly involved in the mechanics of mating.⁹ This level of genitalic complexity is common across insects and is often interpreted as the result of sexual conflict: an evolutionary arms race between males trying to ensure their sperm is used and females retaining some control over paternity.

Mate Guarding and Sperm Competition

For many male grasshoppers, copulation is not the end of the mating effort. After uncoupling, males in several species stay mounted on the female’s back, sometimes for days, physically blocking other males from mating with her. In the eastern lubber grasshopper Romalea microptera, males ride on inseminated females until the female lays her eggs, kicking at any rival that approaches.¹⁰

This guarding behavior reflects a real threat: sperm from a second male can displace or dilute the sperm already stored. Studies of Chorthippus grasshoppers using a sterile-male technique showed that the second male to mate fathered anywhere from half to all of the first clutch of offspring. Over time, this advantage either faded gradually (suggesting the two males’ sperm slowly mixed inside the spermatheca) or stayed high (suggesting the second male’s sperm sat on top of the first male’s in a layered arrangement).¹¹ Either way, the last male to mate often has a significant paternity advantage, which explains why males invest so heavily in post-copulatory guarding.

Lab experiments with the grasshopper Atractomorpha lata confirmed that guarding scales with competition. When the ratio of males to females was skewed toward more males, both copulation and post-copulatory mounting increased sharply compared to balanced or female-biased groups.¹² Males are reading the competitive environment and adjusting their guarding effort accordingly.

How Females Lay Eggs

After mating, the female’s job shifts to finding a suitable egg-laying site, usually a patch of bare or lightly vegetated soil. Grasshoppers in the family Acrididae have two pairs of shovel-shaped ovipositor valves at the tip of the abdomen. The female drives these into the ground, extending her abdomen to remarkable lengths (sometimes several centimeters deep) by rhythmic digging motions, creating a vertical chamber for the eggs.¹³ If you have ever watched a grasshopper seemingly push her abdomen straight down into the soil like a drill, that is exactly what is happening.

The eggs are laid in a tight cluster called a pod, and the female coats them with a frothy secretion. In Romalea microptera, glands beside the reproductive opening produce a chemical that triggers tanning of both eggs and froth over the following hours, hardening and darkening them.¹⁴ The hardened froth cap provides mechanical protection and helps regulate moisture around the developing embryos during the weeks or months before they hatch. A single female may produce multiple egg pods over her adult life, each containing anywhere from a handful to over a hundred eggs depending on the species.

Hormones and Female Receptivity

Whether a female is willing to mate at all depends on her hormonal state. In the grasshopper Gomphocerus rufus, researchers found that removing the corpora allata (small hormone-producing glands near the brain) eliminated female sexual receptivity entirely. Males, on the other hand, continued to court normally after the same surgery.¹⁵ When corpora allata were reimplanted into females that had been surgically deprived of them, yolk production in the ovaries resumed. This hormone-behavior link means that female grasshoppers are physiologically gatekept: they become receptive only when their bodies are ready to produce eggs, which ties mating behavior directly to nutritional condition and ovarian development.

Diet Quality and Reproductive Output

What a female grasshopper eats has a direct effect on how many eggs she produces. Research on Melanoplus sanguinipes showed that egg production dropped when the diet was high in carbohydrates, and it peaked at an intermediate level of dietary nitrogen.¹⁶ Protein, in other words, matters more than sugar for making eggs.

A more targeted experiment took this further. When female grasshoppers were fed a diet whose amino acid composition matched that of vitellogenin (the precursor protein that gets packed into egg yolk), they produced more eggs and also accumulated higher levels of storage proteins in their body compared to females on a nutritionally unbalanced diet.¹⁷ The finding makes intuitive sense: if the building blocks coming in match the building blocks needed for eggs, less metabolic reshuffling is required and more resources end up as offspring. From an ecological perspective, this means grasshopper populations in habitats with high-quality forage should produce more eggs per female than those in protein-poor environments.

Solitarious Versus Gregarious Mating in Desert Locusts

Desert locusts (Schistocerca gregaria) are grasshoppers that famously shift between a solitary phase and a swarming gregarious phase depending on population density. This phase shift changes mating behavior dramatically. Solitarious males invest much more in pre-copulatory courtship: they stridulate more, vibrate their hind legs more, and generally work harder to maintain contact with the female throughout the encounter. Solitarious females, in turn, are more receptive and less likely to reject a courting male.¹⁸

Gregarious males, by contrast, skip much of this courtship. When population density is high and potential mates are everywhere, elaborate signaling may be less necessary, and speed matters more. In cross-phase experiments, the most successful pairing was a gregarious male with a solitarious female, while a solitarious male paired with a gregarious female was least successful. The gregarious female’s high rejection rate overwhelmed the solitarious male’s elaborate courtship, while the gregarious male’s direct approach paired well with the solitarious female’s willingness to mate.¹⁸ This asymmetry could have real consequences for how genes flow between locust phases in wild populations where solitary and swarming individuals occasionally meet.

Does Mating More Help the Female

Females of many grasshopper species mate with multiple males, which raises the question of whether doing so boosts their reproductive output. The answer appears to be: not necessarily. In the grasshopper Sphenarium purpurascens, females that mated with one male actually produced more eggs and heavier egg pods than females that mated with two different males. Longer individual matings did boost fecundity, but adding a second partner did not.¹⁹ This suggests that the benefits of multiple mating in grasshoppers (if any) may be genetic rather than nutritional, or that the costs of mating with additional males, such as exposure to disease, lost foraging time, or physical wear, sometimes outweigh any gains.

Parasites That Undermine Reproduction

Grasshoppers face threats to their reproductive success from parasites. Grasshopper mites (Eutrombidium locustarum) are short-lived ectoparasites that attach to the host and can reduce its reproductive capacity.²⁰ Parasitic nematodes and tachinid flies also target grasshoppers, sometimes castrating them outright by destroying gonadal tissue. In heavily parasitized populations, a meaningful proportion of adults may be functionally sterile despite going through the motions of courtship and mating. For researchers studying grasshopper reproductive behavior in the field, parasite load is one of those confounding variables that can distort what the data seem to show about mate choice and fertility.

How Road Noise Is Changing Grasshopper Songs

One of the more striking findings in recent grasshopper research is that human-generated noise is altering the very songs males use to attract mates. Males of C. biguttulus collected from habitats near busy roads produce courtship signals with higher frequency components than males from quiet habitats, even when both are recorded under identical silent lab conditions.²¹ Low-frequency road noise overlaps with part of the grasshopper’s song spectrum, so shifting the song upward in pitch helps it cut through the din.

Follow-up work showed that this shift has at least two sources. One is developmental plasticity: males raised with road noise playing in the background during their nymphal development produced higher-frequency songs as adults compared to males raised in quiet conditions. The other is a genetic or otherwise more permanent population-level divergence, because males from roadside populations still differed from quiet-population males even after being raised in identical quiet environments.²² Roadside males also had a higher syllable-to-pause ratio in their songs, which is one of the traits that females prefer, raising the possibility that noise-driven changes in song could inadvertently affect female mate choice and sexual selection dynamics in roadside populations.

Similar effects have been documented in related Orthoptera. Male field crickets living near highways chirp at a faster rate than those in quieter areas, and this behavioral adjustment interacts with intrasexual competition: the speed-up is most pronounced when rival males are nearby.²³ Whether these noise-driven changes help or harm the insects in the long run remains an open question. A song shifted to avoid masking by traffic noise might be easier for females to detect, but it could also fall outside the frequency window that females are tuned to prefer, creating a tension between audibility and attractiveness that populations living next to highways must navigate every generation.