Where grasshopper lay eggs that come
- Where grasshopper lay eggs that come
- THE GRASSHOPPER LIFE CYCLE
- GRASSHOPPER CLASSIFICATION
- A Grasshopper’s Life Cycle
- Grasshopper Lifecycle
- Grasshopper Life Cycle
- Where grasshopper lay eggs that come
- Orthoptera & Allied Insects
- Crickets and grasshoppers
- Vermiform larvae
- Courtship display
- Egg laying and oviposition sites
- Thermoregulation and Diapause
- Mortality of Orthoptera
- Natural enemies
Where grasshopper lay eggs that come
- oversized back legs used for jumping
- large compound eyes
- fairly large size
- it’s fluttery way of flying short distances
- often grasshoppers make pops or snaps when they fly
THE GRASSHOPPER LIFE CYCLE
When a female grasshopper is ready to lay her eggs, there’s hardly anyplace better for her to go than an open, sunny field. She needs soil to be loose enough for her to work her rear end into it. Once her rear end is well underground, while she is laying her eggs, a frothy, gluelike substance is deposited over them. This substance hardens around the eggs as it dries. The frothy mass, which can be called an egg pod, dries into something like a stiff sponge, so that when the eggs hatch there’ll be plenty of air for the newborn, and it won’t be too hard for the newborn to escape. The number of eggs in a pod varies from individual to individual, and species to species — maybe as few as six or so, or more than 150. Each female deposits several pods. Some species, instead of laying in pods, just cram them haphazardly here and there in the ground.
So, when young grasshoppers emerge from their eggs, they find themselves inside a honeycombed egg pod, and buried underground. They must push their delicate bodies upward through the soil, especially using their long back legs. During this process their bodies are covered by a membranous hatching skin, which to some degree both protects the body’s delicate parts, but also restricts movements of the legs, making it even harder to push upward.
At the ground’s surface, the hatching skin comes off, giving the legs full mobility. Grasshoppers undergo simple metamorphosis, so immature grasshoppers look more or less like adults, only smaller. As nymphs grow, they molt several times, shedding their “skins,” or exoskeletons. As with other insects that undergo simple metamorphosis, each progressive stage of nymph development is referred to as an “instar,” so we might speak of a 2nd instar grasshopper or a 4th instar one. The final molting results in a full-size adult with wings. Though it varies with species, five or six instar stages usually take place. The time from egg to adult typically is 40 to 60 days. That’s probably a 5th instar nymph in the picture below:
The above grasshopper is clearly a nymph because its wings are so short. The wing is the oval, finely pitted item appearing to issue from beneath the cape-like “back shield,” or prothorax. On an adult grasshopper the wings would project well beyond the abdomen’s rear end, but you can see that on this nymph it reaches only about a fourth of the distance.
Grasshoppers belong to the insect order Orthoptera, which also holds katydids, crickets, mantids, walkingsticks and cockroaches.
But, thing is, when you look at all the kinds of grasshoppers in the world along with all known grasshopper relatives, it becomes hard to decide where grasshoppers end and other insects, such as crickets and katydids, begin and end. According to the Peterson Field Guide A Field Guide to the Insects, here is one breakdown of the different kinds of grasshoppers found in North America:
found in North America
- Short-horned Grasshoppers, family Acrididae
- Long-horned Grasshoppers, family Tettigoniidae
- Cone-headed Grasshoppers, subfamily Copiphorinae
- Meadow Grasshoppers, subfamily Conocephalinae
- Shield-backed Grasshoppers, subfamily Decticinae
- Pygmy Grasshoppers, family Tetrigidae
- Monkey Grasshoppers, family Tanaoceridae
- Eumastacid Grasshopper, family Eumastacidae
Other field guides group them a little differently, plus some experts would refer to our “Meadow Grasshoppers” as “Meadow Katydids,” and make other similar name changes. The truth is that there’s no point to debate what’s a grasshopper and what’s not. The word “grasshopper” is standard English, but it has very little if any scientific value.
If you’d like to see the current breakdown of families and subfamilies in the Orthoptera, showing how grasshoppers mix in with crickets, katydids and the rest, check on the NCBI Taxonomy Browser’s Orthoptera Page.
You’ve probably heard of plagues of locusts and how sometimes vast clouds of them darken the sky. Locusts are grasshoppers. You may be interested in Naturalist Jim’s experience with locusts in Mexico, and seeing some pictures, as reported in his Naturalist Newsletter.
A Grasshopper’s Life Cycle
The grasshopper is a flying animal belonging to order Orthoptera and class Insecta. About 11,000 species exist. They are herbivorous and commonly seen in autumn; a few appear in summer and spring. During mating the male grasshopper deposits sperm into the female’s vagina, which finds its way to the eggs through canals known as micropyles. An adult grasshopper goes through the stages egg, nymph and adult, and has a lifespan of approximately one year.
This is the initial stage of a grasshopper’s life cycle. The mother grasshopper lays fertilized eggs in midsummer, and they remain 1 or 2 inches under the sand or in leaf litter. She sprinkles them with a sticky semisolid substance that sets to form an egg pod. Each egg pod contains 15 to 150 eggs, depending on the species. Normally a female grasshopper can lay up to 25 pods. The eggs remain underneath for about 10 months in autumn and winter before hatching into nymphs during spring or in the initial days of summer.
This is the second stage of the grasshopper’s life cycle and the initial stage during which a young grasshopper sees the outside world. Nymphs look like adult grasshoppers, called molts, apart from the fact that they are wingless and lack reproductive organs. They undergo five substages known as instars before fully developing into adult grasshoppers; each instar is characterized by shedding of the cuticle skin and gradual growth of wings. In order to survive, nymphs start to feed on succulent and soft plant foliage barely one day after hatching from the egg. This stage lasts for about five to six weeks before the young nymphs mature to adult grasshoppers.
Molting takes place during the nymph stage. The locust sheds its exoskeleton before maturing into an adult. While the exoskeleton covers the nymph’s body, providing it with protection against external injuries, it inhibits its growth because of its rigidity and inability to give room for expansion. The nymph has to shed it in order to achieve growth. It undergoes five to six molts in which it changes its structure and form before reaching adulthood.
This is a fully grown grasshopper. It takes about one month before the wings are fully developed. The mature grasshopper is more mobile than the nymph, a characteristic that helps them to hunt and flee from predators. The reproductive organs are fully grown, so the females can lay eggs and the males can fertilize. However, female grasshoppers do not lay eggs until they are 1 or 2 weeks old, to allow them to gain enough weight before they start laying eggs. Once she starts laying eggs, the female continues to lay eggs at intervals of three to four days until she dies. Adult grasshoppers live for about two months, depending on the weather.
Grasshopper Life Cycle
During reproduction, the male grasshopper introduces sperm into the vagina through its aedeagus (reproductive organ), and inserts its spermatophore, a package containing the sperm, into the females ovipositor. The sperm enters the eggs through fine canals called micropyles.
In the summer, the female grasshopper lays the fertilized egg pod, using her ovipositor and abdomen to insert the eggs about one to two inches underground, although they can also be laid in plant roots or even manure and usually in their habitats. These are immediately incubated. She lays the eggs in a row and sprays them with a stick substance which forms a pod. Each ‘pod’ has 15 – 150 eggs inside it, depending on the species. The female grasshopper can lay up to 25 pods.
Grasshoppers undergo simple complete or incomplete metamorphosis that consists of 3 or 4 stages:
Complete metamorphosis: Incomplete metamorphosis:
Grasshopper eggs with one egg split showing a young nymph about to emerge.
Egg pods are oval to elongate and often curved. Often the size of kernels of rice, eggs may be white, yellow-green, tan or various shades of brown depending on the species.
Eggs hatch into nymphs, which look like little adults without wings and reproductive organs. Nymphs resemble small, wingless adults.
Newly hatched nymphs are white, however, after exposure to sunlight, they assume the distinctive colours and markings of adults. Nymphs molt their skins many times as they grow to be adults.
Female grasshoppers try to choose a good place to lay their eggs, however, this is the only parental care they provide. Grasshoppers do not take care of their young once they have hatched.
Where grasshopper lay eggs that come
All grasshoppers begin their lives as eggs. Yet eggs represent the least known stage of the grasshopper life cycle. They are laid in the soil of the habitat and develop hidden from the view of humans. Eggs of a few species, however, have been studied in both field and laboratory (Fig. 9).
Figure 9. One intact and one broken egg pod, exposing the eggs of the migratory grasshopper, Melanoplus sanguinipes (Fabricius).
Incubation of eggs begins immediately after females deposit them in the soil. The embryo, at first a tiny disc of cells laying on the ventral side of the yolk surface and at the posterior end of the eggs (Fig. 10), grows rapidly, receiving nourishment from the nutrient stores in the yolk.
From left to right: Stage 1 (5%) Stage 3 (10%) Stage 7 (20%) Stage 10 (30%) Stage 12 (40%) Stage 19 (50%)
Figure 10. Selected stages in the development of a grasshopper embryo (Melaoplus sanguinipes) held at a constant temperature of 30 C. Left two figures show whole egg; other figures show embryos removed from egg. (Illustrations adapted from Riegert, 1961; stages idetified and designated for embryos of Aulocara elliotti by Saralee Visscher, 1966).
In seven days the embryo of the migratory grasshopper, Melanoplus sanguinipes , held at an incubation temperature of 30½C, reaches Stage 19. In this stage the embryos of many rangeland species such as Aulocara elliotti and Camnula pellucida cease growth and begin a diapause . The embryo of the migratory grasshopper, however, continues to develop and at Stage 20 actively moves from the ventral to the dorsal surface and revolves 180½ on its long axis (see Figure 10, Stage 20). After 15 days the embryo has grown to Stage 24, having achieved 80 percent of its development. It then ceases growth and enters diapause. The embryo of the twostriped grasshopper, and probably others also, enter diapause at this stage. Exposed to favorable incubation temperatures, the eggs of a few rangeland species, such as Arphia conspersa and Xanthippus corallipes , develop completely and hatch during the same summer they are laid. The immediate cause of cessation of embryonic growth (diapause) in eggs of the majority of rangeland grasshoppers appears to be the shutdown of growth hormones. The embryos remain physiologically active as transfer of nutrient materials from the yolk into the embryonic fat body and other tissues continues. Cold temperatures of winter, however, slow or end this process and embryos enter a dormant period.
For eggs laid in temperate regions to reach their maximum development before diapause, they must receive sufficient heat, usually measured as day-degrees of heat accumulated in the soil at egg depth. Eggs deposited late in the season or during a cold summer may not receive this amount of heat, especially in northern areas such as the Canadian provinces of Alberta, Manitoba, and Saskatchewan. Eggs that do not reach their potential stage of development have reduced hatchability the following spring and thus do not contribute as much to the maintenance of a population.
During winter, low ground temperatures eventually break egg diapause. As soon as the ground warms above threshold soil temperatures of 50 to 55½F in spring, the embryos are ready to continue their development. Research has shown that for the few species studied, eggs need 400 day-degrees by fall to attain maximum embryonic growth and another 150 day-degrees in spring to initiate hatching. For completion of embryonic growth from start to finish, eggs require totals of 500 to 600 day-degrees.
In spring the emergence of hatching grasshoppers may be readily observed. All embryos of a single pod usually wriggle out one after another within several minutes. Once out, they immediately shed an embryonic membrane called the serosa. An individual hatchling, lying on its side or back and squirming, takes only a few minutes to free itself (Fig. 11). During this time the hatchlings are susceptible to predation by ants. After the shedding of the membrane the young grasshoppers stand upright and are able to jump away and escape attacking predators. In spring, young grasshoppers have available green and nutritious host plants. The majority of individuals in grasslands are grass feeders, but individuals of some species are mixed feeders, eating both grasses and forbs. Others are strictly forb feeders.
Figure 11. The lifecycle of the bigheaded grasshopper, Alucara ellliotti (Thomas). During summer in bare spots of grassland the female deposits at intervals batches of eggs. As soon as the eggs are laid, they begin embryonic development and reach an advanced stage in which they enter diapause and pass the winter. In spring the eggs complete embryonic devlopment and hatch. The young grasshopper sheds a serosal skin, the exoskeleton hardens, and the nymph begins to feed and grow. After molting five times and developing through five instars in 30-40 days, it becomes an adult grasshopper with functional wings. The adult female matures groups of six to eight eggs at a time and deposits them in the soil at intervwls of three to four days for the duration of her short life.
As insects grow and develop, they molt at intervals, changing structures and their form. This process is called metamorphosis . A number of insects undergo gradual (simple) metamorphosis, such as grasshoppers. With this type of metamorphosis the insect that hatches looks like the adult except for its smaller size, lack of wings, fewer antennal segments, and rudimentary genitalia (Fig. 11). Other insects with gradual metamorphosis include the true bugs, aphids, leafhoppers, crickets, and cockroaches. The majority of insects undergo complete (complex) metamorphosis, as the eggs hatch into wormlike larvae adapted for feeding and have a vastly different appearance from that of the adult insect. Before full-grown larvae can become adult insects they must enter into the pupal stage. In this stage they develop and grow the adult structures. Common examples of insects that undergo complete metamorphosis are beetles, butterflies, bees, wasps, and flies.
For young grasshoppers to continue their growth and development and reach the adult stage, they must periodically molt or shed their outer skin (Fig. 11). Depending on species and sex, they molt four to six times during their nymphal or immature life. The insect between molts is referred to as an instar; a species with five molts thus has five instars. After shedding the serosal skin, the newly hatched nymph is the first instar. After each molt the instar increases by one so that the nymph consecutively becomes a second, third, fourth, and fifth instar. When the fifth instar molts, the grasshopper becomes an adult or an imago.
The new adult has fully functional wings but is not yet ready to reproduce. The female has a preoviposition period of one to two weeks during which she increases in weight and matures the first batch of eggs. Having mated with a male of her species, the female digs a small hole in the soil with her ovipositor and deposits the first group of eggs. Once egg laying begins, the female continues to deposit eggs regularly for the rest of her short life. Depending on the species, production may range from three pods per week to one pod every one to two weeks. The species that lay fewer eggs per pod oviposit more often than those that lay more eggs per pod.
The egg pods of grasshoppers vary not only in the number of eggs they contain but also in their size, shape, and structure. Based on structure, four types have been recognized. In type I a stout pod forms from frothy glue and soil surrounding the eggs; froth is lacking between the eggs. In type II a weaker pod is formed from frothy glue between and surrounding the eggs. In type III frothy glue is present between the eggs but does not completely surround them. In type IV only a small amount of froth is secreted on the last eggs of a clutch, and most of the eggs lie loosely in the soil. Grasshopper eggs themselves vary in size, color, and shell sculpturing. Depending on the species eggs range from 4 to 9 mm long and may be white, yellow, olive, tan, brownish red, or dark brown. Eggs of certain species are two-toned brown and tan.
Events in the life cycle of an individual species of grasshopper — hatching, nymphal development, and adulthood — occur over extended periods. The eggs may hatch over a period of three to four weeks. Nymphs may be present in the habitat eight to ten weeks and adults nine to 11 weeks. Because of the overlapping of stages and instars, raw field data obtained by sampling populations do not answer several important questions. For example, how many eggs hatched? How many individuals molted successfully to the next instar? What was the average duration of each instar? How many became adults? What was the average length of life and the average fecundity of adult females? To obtain answers to these questions, detailed sampling data must be treated mathematically.
Laboratory data may also be used in studying grasshopper life histories. Table 4 provides information on the life history of the migratory grasshopper, Melanoplus sanguinipes , reared at a constant temperature of 86½F and 30-35% relative humidity and fed a nutritious diet of dry feed, green wheat, and dandelion leaves. The entire nymphal period averages 25 days for males and 30 days for females. Each instar takes four to five days to complete development except for the last instar, which takes seven days. Adult longevity of males averages 51 days and females, 52 days. Longevity of adults in the field is no doubt briefer because of the natural predators and parasites cutting short the lives of their prey.
TABLE 4. Life history of the migratory grasshopper, Melanoplus sanguinipes, reared in the laboratory at a constant temperature of 86.5 F.
Orthoptera & Allied Insects
Crickets and grasshoppers
The order Orthoptera is divided into two major divisions: Ensifera (true crickets) and Caelifera (true grasshoppers). Ensifera includes the families Gryllidae (crickets) and Tettigoniidae (bush crickets; long-horn grasshoppers referring to their long antennae). Caelifera encompasses the true grasshoppers in the family Acrididae (short-horn grasshoppers referring to their short antennae).
Orthoptera and allied insects have an incomplete metamorphosis (they are exopterygote). This means that they don’t have a pupal stage and that the immature stages (called nymphs) closely resemble the adults. Female adults lay eggs which vary in size and shape between species. The first instar (first nymphal stage) nymphs hatch (eclose) in the spring when the temperature is suitable for development and food is abundant, especially young, succulent vegetation. The number of nymphal instars (discrete nymphal stages) varies between species but most Acrididae have four nymphal instars and most Tettigoniidae have five or six. Nymphal development takes about two months and the adults usually emerge in July.
Males and females mate after a courtship display in which song (stridulation) plays an important role. Females lay eggs throughout their adult lives. Each species has a preferred habitat for egg laying. The eggs of Tettigoniidae are always laid singly and those of Acrididae are laid in groups protected by a tough case (egg pod). It is possible to identify egg pods to species.
The egg is the overwintering stage for most species of Orthoptera; development of the egg is arrested during winter (diapause). Hatching is triggered by increased temperature and humidity such as after spring rainfall. Nymphs first appear as vermiform larvae on emergence.
Orthoptera hatch as “vermiform larvae” – newly emerged nymphs are surrounded by a protective embryonic cuticle (a thin membranous sleeve). Acrididae need to emerge not only from their egg shell but also from the egg pod. Additionally some acridids and tettigoniids lay their eggs in soil and the vermiform larva has to travel to the soil surface. It is only at the soil surface that the embryonic cuticle is shed and the first instar nymph emerges.
Orthoptera song is produced through stridulation. A typical stridulatory mechanism consists of a file (series of pegs) and a scraper (thickened ridge). Rubbing together of the file and scraper produces the characteristic sound of Orthoptera.
Acridid males are more effective at sound production than females. Their file is longer and has more stridulatory pegs than females. The prominent fore wing veins constitute the scraper. The space between the fore wings is thought to have a role in resonance. Some short winged females (such as the Meadow Grasshopper, Chorthippus parallelus) do not make any sound despite stridulatory movements.
Male acridids are thought to produce five types of song during courtship and mating. The songs vary in intensity of sound, form of pulse and frequency of repetition.
Single males or groups of males produce ‘normal song’ to attract females. Rival males in close proximity to a female can alternately stridulate in a ‘rivals duet’. Females sometimes respond through stridulation as they orientate towards the male. ‘Courtship song’ follows and this form can be elaborate and very different to the ‘normal song’. Some species combine song with dance.
At the end of the courtship display males produce a short ‘assault song’ just prior to mating. In acridids, the male grips the female with his two fore legs and curls his abdomen beneath the female abdomen during mating. The male is hooked to the female through special structures on the male organ. The male sperm is transferred in a package called the spermatophore. During the process of mating the male continues to stridulate producing a ‘copulation song’.
Egg laying and oviposition sites
Female orthoptera position and lay their eggs through structures called ovipositors. In tettigoniids the ovipositor consists of three long valves. Acridids have short, stout anterior and dorsal valves with the inner pair also reduced.
The acridid ovipositor is adapted for laying egg pods into the ground; the short, stout structure is used for digging and probing prior to egg laying. After each egg is laid the female injects a frothy secretion into the hole which mixes with soil particles to form the outer surface of the egg pod. When all the eggs are laid further froth is excreted to complete the egg pod.
The long tettigoniid ovipositor is adapted for laying eggs deep into plant tissue or into the ground. There is considerable variation in ovipositor form between species and this relates to differing functions. Females select an egg-laying site after examining the substrate with the sensory palps (mouthparts). Some species use their mouthparts to bite through the substrate to assist oviposition. The ovipositor is covered with sensory hairs that allow the female to assess the oviposition site and the placement of the egg.
Tettigoniids are relatively specific in oviposition site selection. The acridids all lay their egg pods in the soil.
Table = Preferred egg laying sites for UK short-horn grasshoppers (acridids) (from Waloff, 1950)
|Common name||Scientific name||Egg-laying site|
|Field Grasshopper||Chorthippus brunneus||Soil – upper surface|
|Meadow Grasshopper||Chorthippus parallelus||Soil – upper surface|
|Heath Grasshopper||Chorthippus vagans||Soil – upper surface|
|Rufous Grasshopper||Gomphocerippus rufus||Soil – upper surface|
|Mottled Grasshopper||Myrmeleotettix maculatus||Soil – upper surface|
|Woodland Grasshopper||Omocestus rufipes||Soil – upper surface|
|Stripe-winged Grasshopper||Stenobothrus lineatus||Soil – above grass roots|
|Lesser Marsh Grasshopper||Chorthippus albomarginatus||Vegetation – base of grass blades|
|Large Marsh Grasshopper||Stethophyma grossum||Vegetation – base of grass blades|
|Common Green Grasshopper||Omocestus viridulus||Vegetation – base of grass blades|
Thermoregulation and Diapause
Like all insects, orthopterans are “ectotherms”, a term which signifies that they mostly rely on external sources of heat to raise their body temperature. The internal temperature of ectotherms, therefore, tends to vary, often tracking the ambient temperature of the immediate environment. To cope with this, ectotherms have developed various ways of controlling their body temperatures, for example basking on rocks, moving in and out of shade, and dilating or constricting peripheral blood vessels (see photos). In addition, ectotherms often have more complex metabolisms than endotherms (such as mammals), for example they may have many (up to ten) enzyme systems that operate at different temperatures for an important chemical reaction.
Despite these adaptations, ectothermic animals are often more reliant on environmental conditions than endothermic animals. Therefore, they are often constrained to certain microclimatic conditions and, so, changes in climate can trigger corresponding changes in the distributions of ectothermic animals. Therefore, highly mobile, ectothermic insects, such as grasshoppers and crickets are regarded as valuable indicators of climate change. Long-winged Coneheads (Conocephalus discolor) have been expanding into new territories, with rising temperatures under climate change a likely factor. Until the 1980s they were confined to the South Coast, but they can now be found north of Leicester. Similarly Roesel’s Bush Cricket (Metrioptera roeselii) was largely restricted to the Thames and Solent Estuaries in the mid-20th century, but is now seen across south and central England up to the Midlands.
Many insects in the UK also undergo arrested development in winter, a complex physiological process known as diapause. There is another form of arrested development known as acquiescence. Acquiescence ends as soon as conditions are favourable whereas diapause is not terminated even if ambient conditions are suitable for insect activity. Therefore, diapausing eggs do not hatch until diapause has been completed and even warm weather does not stimulate premature hatching. Diapause is a common phenomenon in insects, for example adult ladybirds enter diapause during winter and undergo reproductive maturation during this period.
Mortality of Orthoptera
Temperature and rainfall are major mortality factors of the egg stage. Eggs laid in soil are vulnerable to waterlogging and egg diapause has precise temperature requirements. Natural enemies of Orthoptera are also important mortality factors.
Microbial pathogens (fungi, bacteria, viruses and nematodes) are important natural enemies of all Orthoptera. The prevalence of these pathogens is predicted to increase with climate change.
A number of parasitoids (parasitic Diptera (flies) or Hymenoptera (wasps) with complex life cycles intimately connected to the host) attack Orthoptera. Chalcid (Hymenoptera) wasps lay their eggs into the eggs of Conocephalus dorsalis. Scelionid wasps from the genus Scelio are egg parasites of acridids. Some species of acridid are attacked by Blaesoxipha laticornis (Diptera: Sarcophagidae) as adults. The female fly is viviparous – instead of laying eggs onto the host, she deposits young larvae onto the grasshopper cuticle. The larvae invade the body cavity of the host and emerge from behind the grasshoppers head as final instar (last stage) larvae ready to pupate in the soil.
Ectoparasitic mites are commonly seen on the bodies of Orthoptera in mainland Europe but rarely in the UK. Warmer UK temperatures could increase the occurrence of these mites.
There is very little information on the predators of Orthoptera although birds, small mammals and reptiles have been observed feeding on them. A number of invertebrate predators are known to consume Orthoptera, including spiders, Sphecidae (hunting wasps), Vespidae (wasps) and Asilidae (robber flies). Tettigoniid nymphs and all stages of acridids have been seen in the low-level webs of the spider Agelena labyrinthica. Some bush-crickets are predatory and consume grasshoppers or younger stages of their own species.
The Orthoptera Species File is a taxonomic database of the world’s Orthoptera, both living and fossil.
Wikipedia article on Tettigoniidae (bush-crickets)
Wikipedia article on Gryllidae (crickets)
Wikipedia article on Caelifera (grasshoppers)