Why Are Grasshoppers Green
- Why Are Grasshoppers Green?
- Eggs in a Pod
- Pigment Plasticity
- Boldly Unpalatable
- Colour and colour change in the grasshopper, Kosciuscola tristis
- Grasshopper Characteristics
- Types of Grasshopper
- Grasshopper Habitat and Grasshopper Diet
- Grasshopper Behaviour
- Grasshopper Predators
- Critter Catalog
- Local animals in this group:
- Additional information:
- What do they look like?
- Where do they live?
- What kind of habitat do they need?
- How do they grow?
- How long do they live?
- How do they behave?
- How do they communicate with each other?
- What do they eat?
- What eats them and how do they avo >Grasshoppers jump or fly away, and then hide if they can. Some species eat toxic plants and keep the toxins in their bodies to discourage predators.
- What roles do they have in the ecosystem?
- Do they cause problems?
- How do they interact with us?
- Are they endangered?
- What triggers colour change? Effects of background colour and temperature on the development of an alpine grasshopper
- J. Pablo Valverde
- Holger Schielzeth
- Colour morph switches
- Temperature-cued colouration darkening
- Green-brown switches
- Colouration darkening
- Experimental setup
- Background colour treatment
- Temperature treatment
- Scoring of body colour
- Statistical analysis
- Availability of supporting data
Why Are Grasshoppers Green?
Birds, reptiles, amphibians, arachnids and insects are all important and effective predators of grasshoppers and their kin. To protect themselves from these predators, grasshoppers use a number of adaptations, including locomotor escape, crypsis and toxins. While most species are green to camouflage with their habitats, others wear bright colors to warn predators of their noxious chemicals.
Eggs in a Pod
Grasshoppers are leaf-eating herbivores — foliovores — who consume a wide variety of plant species. Females lay about 100 eggs per season; they deposit the eggs in small depressions in the soil. After depositing the eggs, the females surround them with a frothy mixture that hardens protectively over the pods. Grasshoppers exhibit incomplete metamorphosis; the young hatch from their eggs as nymphs, which look somewhat similar to the adults.
Unlike many insects that live in secluded places or have nocturnal habits; grasshoppers are diurnal and spend a lot of time in exposed places like meadows, lawns and grasslands. Many grasshoppers feature a mix of green and brown colors to help them camouflage amid the plants, grass and weeds on which they live. Some species exhibit different colors in different portions of their geographic range to blend more effectively with the local vegetation. To further their cryptic efforts, grasshoppers freeze and remain motionless when they see a predator. If the predator gets too close, the grasshoppers will try to jump or fly to safety. Grasshoppers have many predators, including birds, small mammals, lizards, frogs snakes spiders, wasps, robber flies and praying mantises.
Many grasshoppers change their color over time. The nymphs of many species change color with each successive molt, which may be in response to shifts in microhabitat preference. Other species change colors as their food sources change. In 1953, Salahattin Okay of the University of Ankara found that some species changed from green to brown as the humidity level drops. Okay demonstrated that the brown individuals of the species in his study were missing the blue component of their green pigment — eliminating the green color entirely.
Not all grasshoppers are green. Some — for example luber grasshoppers (Romalea microptera) — display bold colors including red, yellow and black. These colors serve as a warning to potential predators that these grasshoppers possess and emit noxious chemicals when threatened. Often, these boldly colored grasshoppers raise their wings, flail their legs and hiss by forcing air through their breathing tubes. The toxins emitted by these grasshoppers can make birds and opossums very ill.
Colour and colour change in the grasshopper, Kosciuscola tristis
The males of the small grasshopper (Kosciuscola tristis), with a restricted range above 1830 m in the Australian Alps, exhibit a remarkable colour change. They are dark, almost black, when cold and change to a bright sky blue colour within minutes of exposure to warmth.
Sections of cuticle fixed in the two conditions confirm that the cells underlying the cuticle contain two kinds of granules: large (diameter 1·0 μm) spherical, brown granules, and smaller (0·17 μm) less dense granules. In the blue (warm) condition the small granules are closely packed in the distal part of the cells, whereas the ‘black’ granules are found predominantly in the deeper proximal zones. Evidence is presented to suggest that the blue colour arises from Tyndall scattering of light by the suspension of small granules and is intensified by being seen against a dark background.
In the black condition the black granules are found to have moved towards the surface, mingling with the smaller granules and ‘quenching’ the light scattering.
The smaller granules are white in the isolated state. They consist of a mixture of uric acid and a pteridine, probably leucopterin.
The epidermal cells contain numerous microtubules, which are directed towards the cell surface, that is, parallel to the direction of movement of the granules. It is possible that the microtubules are associated with the movement.
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Grasshoppers are herbivorous insects of the suborder Caelifera in the order Orthoptera. To distinguish them from bush crickets or katydids, they are sometimes referred to as short-horned grasshoppers. Species that change colour and behaviour at high population densities are called locusts.
A Grasshopper is an amazing insect that can leap 20 times the length of its own body. If you or I could do that, we would be able to jump almost 40 yards!
A Grasshopper does not actually ‘jump’. What they do is use their legs as a catapult. Grasshoppers can both jump and fly and they can reach a speed of 8 miles per hour when flying. There are about 18,000 different species of grasshoppers.
Grasshoppers are medium to large insects. Adult length is 1 to 7 centimetres, depending on the species. Like their relatives the ‘katydids’ and ‘crickets’, they have chewing mouthparts, two pairs of wings, one narrow and tough, the other wide and flexible, and long hind legs for jumping. They are different from these groups in having short antennae that do not reach very far back on their bodies.
Grasshoppers usually have large eyes, and are coloured to blend into their environment, usually a combination of brown, grey or green. In some species the males have bright colours on their wings that they use to attract females. A few species eat toxic plants, and keep the toxins in their bodies for protection. They are brightly coloured to warn predators that they taste bad.
Female grasshoppers are larger than the males and have sharp points at the end of their abdomen that are there to help them lay eggs underground. Male grasshoppers sometimes have special structures on their wings that they rub their hind legs on or rub together to make sounds.
Grasshoppers can be found almost everywhere in the world, except for the colder regions near the North and South poles.
Types of Grasshopper
There are two main groups of grasshoppers:
(1) long-horned grasshoppers
(2) short-horned grasshoppers
Grasshoppers are divided according to the length of their antennae (feelers), which are also called horns. Short-horned grasshoppers are usually called ‘locusts’.
Grasshopper Habitat and Grasshopper Diet
Grasshoppers live in fields, meadows and just about anywhere they can find generous amounts of food to eat. A grasshopper has a hard shell and a full grown grasshopper is about one and a half inches, being so small you would not think they would eat much – but you would be so wrong – they eat lots and lots – an average grasshopper can eat 16 time its own weight.
The grasshoppers favourite foods are grasses, leaves and cereal crops. One particular grasshopper – the Shorthorn grasshopper only eats plants, but it can go berserk and eat every plant in sight – makes you wander where they put it all.
Grasshoppers are most active during the day, but also feed at night. They do not have nests or territories and some species go on long migrations to find new supplies of food. Most species are solitary and only come together to mate, but the migratory species sometimes gather in huge groups of millions or even billions of individuals.
When a grasshopper is picked up, they ‘spit’ a brown liquid which is known as ‘tobacco juice’. Some scientists believe that this liquid may protect grasshoppers from attacks by insects such as ants and other predators – they ‘spit’ the liquid at them then catapult up and fly off quickly.
Grasshoppers also try to escape from their enemies hiding in the grass or among leaves. If you have ever tried to catch grasshoppers in a field, you know how quickly they can disappear by dropping down into the tall grass.
The grasshoppers greatest enemies include various kinds of flies that lay their eggs in or near grasshopper eggs. After the fly eggs hatch, the newborn flies eat the grasshopper eggs. Some flies will even lay their eggs on the grasshoppers body, even while the grasshopper is flying. The newborn flies then eat the grasshopper. Other enemies of grasshoppers include beetles, birds, mice, snakes and spiders.
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Find grasshoppers information at
What do they look like?
Grasshoppers are medium to large insects. Adult length is 1 to 7 cm, depending on the species. Like their relatives the katydids and crickets, they have chewing mouthparts, two pairs of wings, one narrow and tough, the other wide and flexible, and long hind legs for jumping. They are different from these groups in having short antennae that don’t reach very far back on their bodies.
Grasshoppers usually have large eyes, and are colored to blend into their environment, usually a combination of brown, gray or green. In some species the males have bright colors on their wings that they use to attract females. A few species eat toxic plants, and keep the toxins in their bodies for protection. They are brightly colored to warn predators that they taste bad.
Female grasshoppers are larger than the males, and have sharp points at the end of their abdomen that they to help lay eggs underground. Male grasshoppers sometimes have special structures on their wings that they can rub their hind legs on or rub together to make sounds.
- Other Physical Features
- bilateral symmetry
- Sexual Dimorphism
- female larger
- male more colorful
- Range length 1.0 to 7.0 cm 0.39 to 2.76 in
Where do they live?
Grasshoppers are found on all continents except Antarctica. There are over 10,000 species of grasshoppers known, about 50 of which are found in Michigan.
What kind of habitat do they need?
Most grasshoppers prefer dry open habitats with lots of grass and other low plants, though some species live in forests or jungles. Many of the grassland species invade farmer’s fields too.
How do they grow?
Grasshoppers all hatch from eggs, and as they grow they go through incomplete metamorphosis. This means that each stage looks a lot like the adult, but adds a few changes each time the young grasshopper sheds its skin. Grasshoppers usually shed 5 or 6 times. After the last time, they are adults and can reproduce. Most species also get wings when they are adults.
How long do they live?
Most grasshoppers can only survive the winter as an egg; the adults all die when it gets cold. In warm climates which don’t have freezing winters, grasshoppers can probably live longer, maybe for several years. Most die long before that though, from disease or predators or drought.
How do they behave?
Grasshoppers are most active during the day, but also feed at night. They don’t have nests or territories, and some species go on long migrations to find new supplies of food. Most species are solitary, and only come together to mate, but the migratory species sometimes gather in huge groups of millions or even billions of individuals.
How do they communicate with each other?
Grasshoppers mainly use sound and sight to communicate, though like animals, scent and touch are important during mating. In some species males vibrate their wings or rub their wings with their legs to make sounds that attract females.
What do they eat?
Grasshoppers are herbivores, they eat plants. They mostly eat leaves, but also flowers, stems and seeds. Sometimes they also scavenge dead insects for extra protein.
What eats them and how do they avo >Grasshoppers jump or fly away, and then hide if they can. Some species eat toxic plants and keep the toxins in their bodies to discourage predators.
What roles do they have in the ecosystem?
Grasshoppers can be important herbivores. There are sometimes so many, eating so much, that they change the richness and abundance of plant species where they live.
Do they cause problems?
Some grasshopper species are important pests of agriculture. They eat the plants that farmers grow in their fields. This is not usually a big problem in North America, but it has been in the past, and is still a major problem in Africa and Asia.
- Ways that these animals might be a problem for humans
- crop pest
How do they interact with us?
Grasshoppers are an important food for other animals. Some species eat weed plants that are bad for cattle and horses.
Are they endangered?
No grasshoppers are known to be endangered.
- IUCN Red List [Link] Not Evaluated
George Hammond (author), Animal Diversity Web.
What triggers colour change? Effects of background colour and temperature on the development of an alpine grasshopper
J. Pablo Valverde
Department of Evolutionary Biology, Bielefeld University, Morgenbreede 45, 33615, Bielefeld, Germany
Department of Evolutionary Biology, Bielefeld University, Morgenbreede 45, 33615, Bielefeld, Germany
Colour polymorphisms are a fascinating facet of many natural populations of plants and animals, and the selective processes that maintain such variation are as relevant as the processes which promote their development. Orthoptera, the insect group that encompasses grasshoppers and bush crickets, includes a particularly large number of species that are colour polymorphic with a marked green-brown polymorphism being particularly widespread. Colour polymorphism has been associated with the need for crypsis and background matching and background-dependent homochromy has been described in a few species. However, when and how different environmental conditions influence variation in colour remains poorly understood. Here we test for effects of background colour and ambient temperature on the occurrence of colour morph switches (green to brown or brown to green) and developmental darkening in the alpine dwelling club-legged grasshopper Gomphocerus sibiricus.
We monitored individually housed nymphae across three of their four developmental stages and into the first week after final ecdysis. Our data show an absence of colour morph switches in G. sibiricus, without a single switch observed in our sample. Furthermore, we test for an effect of temperature on colouration by manipulating radiant heat, a limiting factor in alpine habitats. Radiant heat had a significant effect on developmental darkening: individuals under low radiant heat tended to darken, while individuals under high radiant heat tended to lighten within nymphal stages. Young imagoes darkened under either condition.
Our results indicate a plastic response to a variable temperature and indicate that melanin, a multipurpose pigment responsible for dark colouration and presumed to be costly, seems to be strategically allocated according to the current environmental conditions. Unlike other orthopterans, the species is apparently unable to switch colour morphs (green/brown) during development, suggesting that colour morphs are determined genetically (or very early during development) and that other processes have to contribute to crypsis and homochromy in this species.
Colour polymorphism has fascinated biologists since the time of Darwin, and its evolutionary meaning is still being revealed [1–3]. Colour polymorphism, defined here as within-species phenotypic variation, occurs throughout the animal kingdom in several taxa of birds, fish, mammals, frogs, molluscs, spiders, several insect orders and also in plants [4–9]. The occurrence of colour polymorphisms in natural populations can result from biased mutation, pleiotropy and trade-offs, gene flow, spatially and/or temporally fluctuating selection and negative frequency-dependent selection that can counter loss of variation by genetic drift [10–13]. Furthermore, developmental plasticity and phenotypic flexibility, if they do not invoke significant cost, might allow the maintenance of polymorphisms. This can be particularly advantageous in unpredictably variable environments.
Insects offer a multitude of examples for the coexistence of two or more colour morphs in groups such as grasshoppers, mantoids, cicadids, damselflies, lepidopterans and beetles [13–15]. There is ample evidence for genetic and environmental effects, as well as genotype-by-environment interactions in colour determination [14–18]. Several species appear capable of modifying their colour in response to various environmental cues such as temperature, predation threats, behaviour stimulus (e.g., crab spiders which try to blend with their background to ambush prey, ), among others . Within Orthoptera, colour polymorphism is present in dozens of species (reviewed in , see also [19, 20]). Two particularly eye-catching forms of colour polymorphism in orthopterans are a widespread green-brown polymorphism in grasshoppers and bush crickets and the famous phase polymorphism in locusts [14, 21]. Phase polymorphism is triggered by changes in population density which induces changes in colour (typically black patterns in gregarious versus pale green or brown colours in solitary phases) as part of more complex changes in morphology, physiology, behaviour and life history [22–26].
The green-brown polymorphism is far more widespread among orthopterans than phase polymorphism and does not correlate with obvious changes in morphology and/or behaviour. Many families and genera of orthopterans comprise species that display either green or brown morphs, while other species are polymorphic (e.g., in genera Decticus, Metrioptera, Oedaleus). In some species, one of the morphs is very rare (such as brown morphs in Decticus verrucivorus), while in others the ratios are far more even (as in Metrioptera roeselii) . With respect to environmental effects, green morphs seem to develop primarily under high humidity, while brown morphs are favoured under dry environmental conditions [15, 27, 28]. Besides the two very striking forms of colour polymorphism mentioned before, there is a range of more fine-scaled within-species variation in colour pattern and colouration among orthopterans [29, 30]. Groundhoppers, for example, differ substantially in their colour patterns, which can be categorized into variable numbers of discrete morphs [31, 32]. In other species, differences in colour are more continuous such as with colouration of species in the genus Oedipoda. Such fine-scaled variation seems to be partly under genetic, partly under environmental control [15, 16, 33]. Many species also show occasional pinkish, purple, yellow or blue colour morphs , further illustrating the diversity of colour in orthopterans.
A very interesting phenomenon associated with colour polymorphism is homochromy, which describes matching of body colouration with variation in the background pattern of the local habitat [14, 15, 20, 35]. Such matching might arise for four different reasons: (i) local adaptation due to multi-generational history of selection on genetic polymorphisms, (ii) selective mortality within generations, (iii) individual-level choice of matching habitat patches , and (iv) developmental plasticity of body colouration to match local conditions . Developmental switches are particularly intriguing, because they allow individual-level matching, which is likely advantageous if habitats are unpredictably variable across generations, but predictable from environmental cues over the lifetime of individuals. Developmental matching has been reported in orthopterans for species with fine-scale variation in colour pattern [37, 38], but also for species which present the green and brown colour polymorphism (Table 1 ).
Studies on the effects of background colouration on the occurrence of colour morph switches in green-brown polymorphic (upper section) and other polymorphic (lower section) orthopterans
|Proportion of Switches|
|Species||Background Material||matched||non-matched||matched||non-matched||Stages with Switches||Reference|
|a) Green-Brown Polymorphism|
|Acrida turrita||fresh/dry grass||62||145||4 %||86 %||after ecdysis|||
|Acrida turrita||painted sawdust||14||15||0 %||100 %||after ecdysis|||
|Acrida turrita||painted sawdust||32||0 %||imago|||
|Oedaleus decorus||NA||10||66||0 %||88 %||after ecdysis|||
|Schistocerca americana||coloured paper||74||0 %||across stages|||
|Schistocerca gregaria||coloured paper||58||312||0 %||63.5 %||within stages|||
|Locusta migratoria||coloured paper||58||237||69 %||24 %||across stages|||
|Rhammatocerus||habitat background||3000 >||90 % >||imago|||
|Chorthippus biggutulus||coloured paper||257||30 %||across stages|||
|b) Other Polymorphisms|
|Oedipoda sp.||earth, clay, coal, stone, chalk||12||92||0 %||80 %||after ecdysis|||
|Tetrix subulata||sand||312||16 %||across stages|||
|Tetrix ceperoi||sand||228||16 %||across stages|||
The proportion of switches was calculated for various studies based on multiple assays either on matched or non-matched background colour. Studies do not indicate precise time of colour morph switch occurrence, only final results of repeated colour assessments across nymphal stages are stated (in the case of Ergene all switches occur after an ecdysis event). Percentages reflect amount of indiv >
Orthopterans are preyed upon by a large diversity of species, including birds, lizards, amphibians, spiders and other insects and are frequently parasitized by parasitic flies and mites [24, 34]. Visually hunting predators might constitute a force that can favour homochromy and crypsis, since survival to the imago stage is critical to individual fitness. Predators might also impose frequency-dependent selection if they develop search images and preferentially prey upon the most common morphs . However, there are other influences that might affect body colour and this may or may not be in conflict with crypsis. For example, body colour is likely to affect the absorption of radiant heat and therefore play an important role in thermoregulation [13, 39–41]. It has repeatedly been reported that orthopterans raised under cool conditions are darker than those raised under warm conditions [16, 19, 42–44].
The club-legged grasshopper Gomphocerus sibiricus is a highly sexually dimorphic alpine dwelling grasshopper that exhibits the green-brown polymorphism present in many other orthopterans. Green individuals are rarer than brown morphs in most populations. Despite substantial fluctuations in population density [24, 45], the species does not show any typical phase polymorphism . It inhabits alpine pastures and grassland with a very heterogeneous composition of open terrain strewn with stones and mottled by various types of short grasses and herbaceous plants. Climate conditions in the mountains are very unpredictable and variable within and between years. The maintenance of the green-brown colour polymorphism could be aided by the heterogeneous habitat and/or temporal variability in climate conditions in the native habitat of G. sibiricus.
In the present study we aimed to test the effect of two known factors on developmental colour changes in G. sibiricus. First, we assessed the effect of background colour (green or brown) on colour morph development across almost the entire ontogeny. We were particularly interested in whether individuals are able to switch colour morphs to achieve homochromy as it has been described in other species (Table 1 ). We predicted that if individuals were able to switch colour morphs, then individuals whose colour morph mismatched the background colour would be capable of matching their background at an advanced developmental stage. Second, we assessed the effect of temperature by means of a radiant heat treatment on developmental darkness, while controlling for humidity, population density and food moisture content. Here we predicted that if individuals were capable of manipulate the degree of melanin in their cuticle, thermoregulation needs would promote a colouration darkening under conditions of low radiation. We followed individuals from the second nymphal stage through to the imaginal stage during two independent rounds of trials with two different radiant heat regimes. Individuals were exposed to experimental treatments from the second nymphal stage onwards. The long exposure to experimental conditions allowed us to evaluate if colour changes occur exclusively in connection with moults or if changes were possible even within nymphal stages.
A total of 78 indiv >2 = 5.05, df = 1, p = 0.025).
Colour morph switches
No colour morph switch was observed among the 34 individuals in cages with matched background colours (6 green individuals in green cages and 28 brown in brown cages in total for both rounds). Forty-four individuals (33 brown and 11 green) were exposed to unmatched backgrounds, but no colour morph switches were observed among these 44 individuals. Reasoning based on binomial sampling (see methods section) suggests that if G. sibiricus is capable of switch colour, the rate of colour morph switches is well below values reported in previous studies (c ≤ 0.07, Table 2 ). When we concentrate on the subset of the data where colour morph switches were most likely, given both non-matched background and temperature treatment (brown individuals on a green background under high radiant heat treatment), the probability of colour morph switch is still well below expectations (c ≤ 0.17, Table 2 ).
Number of individuals of G. sibiricus on mismatched backgrounds, all of which did not switch colour morph during development
|Morph & Background||Temperature|
|Green on Brown||n = 3||n = 0||n = 3|
|c ≤ 0.63||NA||c ≤ 0.63|
|Brown on Green||n = 9||n = 9||n = 18|
|c ≤ 0.28||c ≤ 0.28||c ≤ 0.15|
|Sum||n = 12||n = 9||n = 21|
|c ≤ 0.22||c ≤ 0.28||c ≤ 0.13|
|Morph & Background||Temperature|
|Green on Brown||n = 4||n = 4||n = 8|
|c ≤ 0.53||c ≤ 0.53||c ≤ 0.31|
|Brown on Green||n = 7||n = 8||n = 15|
|c ≤ 0.35||c ≤ 0.31||c ≤ 0.18|
|Sum||n = 11||n = 12||n = 23|
|c ≤ 0.24||c ≤ 0.22||c ≤ 0.12|
|Round 1 + 2|
|Morph & Background||Temperature|
|Green on Brown||n = 7||n = 4||n = 11|
|c ≤ 0.35||c ≤ 0.53||c ≤ 0.24|
|Brown on Green||n = 16||n = 17||n = 33|
|c ≤ 0.17||c ≤ 0.16||c ≤ 0.09|
|Sum||n = 23||n = 21||n = 44|
|c ≤ 0.012||c ≤ 0.13||c ≤ 0.07|
Table depicts number of indiv >
Temperature-cued colouration darkening
We observed a significant change in colouration darkness in both rounds of trials. Individuals in the second and third nymphal stages (N2 and N3) of the round 1, and in the N2 and N4 stages of the round 2 experienced a change in darkness which depended on the direction of the temperature treatment. Individuals in the low radiant heat treatment became darker in colour, while those in the high radiant heat treatment became lighter in colour (Table 3 , Fig. 1 ). Individuals in the N3 stage in the R2 did not show a significant change in colour, yet the sign of the point estimate is the same as in stages N2 and N4. Individuals in the N4 stage of the R1 and under a high radiant heat treatment got significantly darker with age. Most of the low radiant heat treatment individuals from the R1 had perished, with the single remaining individual becoming lighter. Unlike the situation in nymphal stages, individuals in the imago stage undergo a darkening in colour in both treatments within the first week after final ecdysis (Fig. 1 ).
Results of the random-slope mixed effects model used to test for effects of radiant heat treatment and larval age on colouration darkness in both green and brown coloured morphs
|N2 (n = 42)||N2 (n = 35)|
|N1||First nymphal stage|
|N2||Second nymphal stage|
|N3||Third nymphal stage|
|N4||Fourth nymphal stage|
The authors declare that they have no competing interests.
JPV and HS perceived and designed the experiment. JPV performed the experiments and drafted the manuscript. JPV and HS analysed the data and the manuscript. All authors read and approved the final manuscript.