A larva ( / ˈ l ɑːr v ə / ; pl. : larvae / ˈ l ɑːr v iː / ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects , some arachnids , amphibians , or cnidarians typically have a larval phase of their life cycle .
101-678: Caterpillars ( / ˈ k æ t ər p ɪ l ər / KAT -ər-pil-ər ) are the larval stage of members of the order Lepidoptera (the insect order comprising butterflies and moths ). As with most common names, the application of the word is arbitrary, since the larvae of sawflies (suborder Symphyta) are commonly called caterpillars as well. Both lepidopteran and symphytan larvae have eruciform body shapes. Caterpillars of most species eat plant material ( often leaves ), but not all; some (about 1%) eat insects , and some are even cannibalistic. Some feed on other animal products. For example, clothes moths feed on wool, and horn moths feed on
202-548: A pupal stage before becoming adults. Caterpillars grow very quickly; for instance, a tobacco hornworm will increase its weight ten-thousandfold in less than twenty days. An adaptation that enables them to eat so much is a mechanism in a specialized midgut that quickly transports ions to the lumen (midgut cavity), to keep the potassium level higher in the midgut cavity than in the hemolymph . Most caterpillars are solely herbivorous . Many are restricted to feeding on one species of plant, while others are polyphagous. Some, including
303-458: A supergene for the development of butterfly color patterns. The model is supported by computational simulations of population genetics . The Batesian mimicry in Papilio polytes is controlled by the doublesex gene. Some mimicry is imperfect. Natural selection drives mimicry only far enough to deceive predators. For example, when predators avoid a mimic that imperfectly resembles a coral snake,
404-484: A caterpillar with an aggressive defense mechanism will learn and avoid future attempts. Some caterpillars regurgitate acidic digestive juices at attacking enemies. Many papilionid larvae produce bad smells from extrudable glands called osmeteria . Many caterpillars display feeding behaviors which allow the caterpillar to remain hidden from potential predators. Many feed in protected environments, such as enclosed inside silk galleries, rolled leaves or by mining between
505-418: A complex cluster of linked genes that cause large changes in morphology. The second step consists of selections on genes with smaller phenotypic effects, creating an increasingly close resemblance. This model is supported by empirical evidence that suggests that a few single point mutations cause large phenotypic effects, while numerous others produce smaller effects. Some regulatory elements collaborate to form
606-416: A deceptive distraction display to lure predators away from their flightless young: When a man comes by chance upon a young brood [of partridges], and tries to catch them, the hen-bird rolls in front of the hunter, pretending to be lame: the man every moment thinks he is on the point of catching her, and so she draws him on and on, until every one of her brood has had time to escape; hereupon she returns to
707-583: A distinct environment, larvae may be given shelter from predators and reduce competition for resources with the adult population. Animals in the larval stage will consume food to fuel their transition into the adult form. In some organisms like polychaetes and barnacles , adults are immobile but their larvae are mobile, and use their mobile larval form to distribute themselves. These larvae used for dispersal are either planktotrophic (feeding) or lecithotrophic (non-feeding) . Some larvae are dependent on adults to feed them. In many eusocial Hymenoptera species,
808-467: A dormant state. The appearance of a caterpillar can often repel a predator: its markings and certain body parts can make it seem poisonous, or bigger in size and thus threatening, or non-edible. Some types of caterpillars are indeed poisonous or distasteful and their bright coloring warns predators of this . Others may mimic dangerous caterpillars or other animals while not being dangerous themselves. Many caterpillars are cryptically colored and resemble
909-509: A drug-induced dream, while in labor, that she captures a caterpillar and holds it firmly in her hand. In The Sopranos season 5 episode " The Test Dream ", Tony Soprano dreams that Ralph Cifaretto has a caterpillar on his bald head that changes into a butterfly. Click left or right for a slide show. Larva A larva's appearance is generally very different from the adult form ( e.g. caterpillars and butterflies ) including different unique structures and organs that do not occur in
1010-645: A family totally different in structure and metamorphosis from the Heliconidae , without examining them closely after capture. The German naturalist Fritz Müller also spent many years studying butterflies in the Amazon rainforest. He first published a journal article on mimicry in German in 1878, followed in 1879 by a paper to the Entomological Society of London (translated and presented by Ralph Meldola). He described
1111-430: A genus of flatworm , matures in the digestive system of songbirds , their eggs then passing out of the bird in the faeces . They are then taken up by Succinea , a terrestrial snail. The eggs develop in this intermediate host , and must then find a suitable bird to mature in. Since the host birds do not eat snails, the sporocyst has another strategy to reach its host's intestine. They are brightly coloured and move in
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#17328686845731212-431: A mimic resembles a model, so as to deceive a dupe, all three being of different species. A Batesian mimic, such as a hoverfly , is harmless, while its model, such as a wasp , is harmful, and is avoided by the dupe, such as an insect-eating bird. Birds hunt by sight, so the mimicry in that case is visual, but in other cases mimicry may make use of any of the senses. Most types of mimicry, including Batesian, are deceptive, as
1313-431: A pulsating fashion. A sporocyst-sac pulsates in the snail's eye stalks, coming to resemble an irresistible meal for a songbird. In this way, it can bridge the gap between hosts, allowing it to complete its life cycle. A nematode ( Myrmeconema neotropicum ) changes the colour of the abdomen of workers of the canopy ant Cephalotes atratus to make it appear like the ripe fruits of Hyeronima alchorneoides . It also changes
1414-548: A reward. This reproductive mimicry may not be readily apparent as members of the same species may still exhibit some degree of sexual dimorphism . It is common in many species of Caricaceae . In Dodsonian mimicry, named after Calaway H. Dodson , the model belongs to a different species than the mimic. By resembling the model, a flower can lure its pollinators without offering nectar. The mechanism occurs in several orchids, including Epidendrum ibaguense which mimics flowers of Lantana camara and Asclepias curassavica , and
1515-527: A situation where different species were each unpalatable to predators, and shared similar, genuine, warning signals. Bates found it hard to explain why this should be so, asking why they should need to mimic each other if both were harmful and could warn off predators on their own. Müller put forward the first mathematical model of mimicry for this phenomenon: if a common predator confuses the two species, individuals in both those species are more likely to survive, as fewer individuals of either species are killed by
1616-461: A twig or flower, they commonly do so upside down and shift their rear wings repeatedly, causing antenna-like movements of the "tails" on their wings. Studies of rear-wing damage support the hypothesis that this strategy is effective in deflecting attacks from the insect's head. Aggressive mimicry is found in predators or parasites that share some of the characteristics of a harmless species, allowing them to avoid detection by their prey or host ;
1717-412: Is a sheep in wolf's clothing . Mimics are less likely to be found out (for example by predators) when in low proportion to their model. Such negative frequency-dependent selection applies in most forms of mimicry. Specifically, Batesian mimicry can only be maintained if the harm caused to the predator by eating a model outweighs the benefit of eating a mimic. The nature of learning is weighted in favor of
1818-586: Is a combination of visual, by olfaction , and by touch. Vavilovian mimicry is found in weeds that come to share characteristics with a domesticated plant through unintentional selection . It is named after Russian botanist and geneticist Nikolai Vavilov . Selection against the weed may occur either by manually killing the weed, or by separating its seeds from those of the crop by winnowing . Vavilovian mimicry illustrates unintentional selection by man . Weeders do not want to select weeds and their seeds that look increasingly like cultivated plants, yet there
1919-441: Is a postulated form of automimicry ; where the model belongs to the same species as the mimic. This is the analogue of Batesian mimicry within a single species, and occurs when there is a palatability spectrum within a population. Examples include the monarch and the queen from the subfamily Danainae , which feed on milkweed species of varying toxicity. These species store toxins from its host plant, which are maintained even in
2020-414: Is also unclear. The model is usually another species, except in automimicry , where members of the species mimic other members, or other parts of their own bodies, and in inter-sexual mimicry, where members of one sex mimic members of the other. Many types of mimicry have been described. An overview of each follows, highlighting the similarities and differences between the various forms. Classification
2121-602: Is among the most potent defensive chemicals in any animal is produced by the South American silk moth genus Lonomia . Its venom is an anticoagulant powerful enough to cause a human to hemorrhage to death (See Lonomiasis ). This chemical is being investigated for potential medical applications. Most urticating hairs range in effect from mild irritation to dermatitis . Example: brown-tail moth . Plants contain toxins which protect them from herbivores, but some caterpillars have evolved countermeasures which enable them to eat
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#17328686845732222-405: Is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. Often, mimicry functions to protect from predators . Mimicry systems have three basic roles: a mimic, a model, and a dupe. When these correspond to three separate species, the system is called disjunct; when
2323-568: Is another approach used in reducing the impact of caterpillars on crop plants. Some caterpillars are used in industry. The silk industry is based on the silkworm caterpillar. Caterpillar hair can be a cause of human health problems. Caterpillar hairs sometimes have venoms in them and species from approximately 12 families of moths or butterflies worldwide can inflict serious human injuries ranging from urticarial dermatitis and atopic asthma to osteochondritis , consumption coagulopathy , kidney failure , and brain bleeding . Skin rashes are
2424-465: Is based on Antonio Berlese classification in 1913. There are four main types of endopterygote larvae types: Mimicry In evolutionary biology , mimicry is an evolved resemblance between an organism and another object, often an organism of another species. Mimicry may evolve between different species, or between individuals of the same species. In the simplest case, as in Batesian mimicry ,
2525-401: Is inherited through the female line in so-called gentes (gens, singular). Intraspecific brood parasitism, where a female lays in a conspecific's nest, as illustrated by the goldeneye duck ( Bucephala clangula ), do not involve mimicry The parasitic butterfly Phengaris rebeli parasitizes the ant species Myrmica schencki by releasing chemicals that fool the worker ants to believe that
2626-434: Is no other option. For example, early barnyard grass, Echinochloa oryzoides , is a weed in rice fields and looks similar to rice; its seeds are often mixed in rice and have become difficult to separate through Vavilovian mimicry. Vavilovian mimics may eventually be domesticated themselves, as in the case of rye in wheat; Vavilov called these weed-crops secondary crops . Inter-sexual mimicry (a type of automimicry, as it
2727-594: Is not limited to animals; in Pouyannian mimicry , an orchid flower is the mimic, resembling a female bee, its model; the dupe is the male bee of the same species, which tries to copulate with the flower, enabling it to transfer pollen, so the mimicry is again bipolar. In automimicry , another bipolar system, model and mimic are the same, as when blue lycaenid butterflies have 'tails' or eyespots on their wings that mimic their own heads, misdirecting predator dupes to strike harmlessly. Many other types of mimicry exist. Use of
2828-461: Is often based on function with respect to the mimic (e.g., avoiding harm). Some cases may belong to more than one class, e.g., automimicry and aggressive mimicry are not mutually exclusive, as one describes the species relationship between model and mimic, while the other describes the function for the mimic (obtaining food). The terminology used has been debated, as classifications have differed or overlapped; attempts to clarify definitions have led to
2929-412: Is one species that preys upon caterpillars. The flycatcher typically finds caterpillars among oak foliage. Paper wasps , including those in the genus Polistes and Polybia catch caterpillars to feed their young and themselves. Caterpillars have been called "eating machines", and eat leaves voraciously. Most species shed their skin four or five times as their bodies grow, and they eventually enter
3030-449: Is pollinated by monarch butterflies and perhaps hummingbirds . Brood parasitism or Kirbyan mimicry is a two species system where a brood parasite mimics its host. Cuckoos are a canonical example; the female cuckoo has its offspring raised by a bird of a different species, cutting down the biological mother's parental investment . The ability to lay eggs that mimic the host eggs is the key adaptation . The adaptation to different hosts
3131-416: Is to mimic a mutualistic symbiont of the prey. Cleaner fish eat parasites and dead skin from client fish. Some allow the cleaner to venture inside their body to hunt these parasites. However, the sabre-toothed blenny or false cleanerfish ( Aspidontus taeniatus ) mimics the bluestreak cleaner wrasse ( Labroides dimidiatus ), which is recognized by other fishes as a cleaner. The false cleanerfish resembles
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3232-466: Is unlike Müllerian mimicry, where the most harmful species is the model. But if a predator dies on its first encounter with a deadly snake, it has no occasion to learn to recognize the snake's warning signals. There would then be no advantage for an extremely deadly snake in being aposematic: any predator that attacked it would be killed before it could learn to avoid the deadly prey, so the snake would be better off being camouflaged to avoid attacks. But if
3333-421: Is widely accepted that mimicry evolves as a positive adaptation. The lepidopterist and novelist Vladimir Nabokov however argued that although natural selection might stabilize a "mimic" form, it would not be necessary to create it. The most widely accepted model used to explain the evolution of mimicry in butterflies is the two-step hypothesis. The first step involves mutation in modifier genes that regulate
3434-429: Is within a single species) occurs when individuals of one sex in a species mimic members of the opposite sex to facilitate sneak mating . An example is the three male forms of the marine isopod Paracerceis sculpta . Alpha males are the largest and guard a harem of females. Beta males mimic females and manage to enter the harem of females without being detected by the alpha males allowing them to mate. Gamma males are
3535-418: The clothes moth , feed on detritus . Some are predatory, and may prey on other species of caterpillars (e.g. Hawaiian Eupithecia ). Others feed on eggs of other insects, aphids, scale insects, or ant larvae. A few are parasitic on cicadas or leaf hoppers ( Epipyropidae ). Some Hawaiian caterpillars ( Hyposmocoma molluscivora ) use silk traps to capture snails. Many caterpillars are nocturnal. For example,
3636-576: The lichens of the oak on which I took it. The spectre tribe ( Phasma ) go still further in this mimicry, representing a small branch with its spray. The English naturalist Henry Walter Bates worked for several years on butterflies in the Amazon rainforest . Returning home, he described multiple forms of mimicry in an 1862 paper at the Linnean Society in London, and then in his 1863 book The Naturalist on
3737-617: The locust , thus they are one of the plagues of Egypt. Jeremiah names them as one of the inhabitants of Babylon . The English word caterpillar derives from the old French catepelose (hairy cat) but merged with the piller (pillager). Caterpillars became a symbol for social dependents. Shakespeare 's Bolingbroke described King Richard 's friends as "The caterpillars of the commonwealth, Which I have sworn to weed and pluck away". In 1790 William Blake referenced this popular image in The Marriage of Heaven and Hell when he attacked priests: "as
3838-443: The turkey vulture . It flies amongst the vultures, effectively camouflaged as a vulture which poses no threat to the hawk's prey. It hunts by suddenly breaking from the formation and ambushing its prey. Parasites can be aggressive mimics, though the situation is somewhat different from those outlined previously. They can mimic their hosts' natural prey, allowing themselves to be eaten as a pathway into their host. Leucochloridium ,
3939-451: The "cutworms" (of the family Noctuidae ) hide at the base of plants during the day and only feed at night. Others, such as spongy moth ( Lymantria dispar ) larvae, change their activity patterns depending on density and larval stage, with more diurnal feeding in early instars and high densities. Caterpillars cause much damage, mainly by eating leaves. The propensity for damage is enhanced by monocultural farming practices, especially where
4040-484: The Christian tradition. Goedart thus located his empirical observations on the transformation of caterpillars into butterflies in the Christian tradition. As such he argued that the metamorphosis from caterpillar into butterfly was a symbol, and even proof, of Christ's resurrection. He argued "that from dead caterpillars emerge living animals; so it is equally true and miraculous, that our dead and rotten corpses will rise from
4141-556: The River Amazons . The term "Batesian mimicry" has since been used in his honour, its usage becoming restricted to the situation in which a harmless mimic gains protection from its predators by resembling a distasteful model. Among the observations in Bates's 1862 paper is the statement: I was never able to distinguish the Leptalides from the species they imitated, although they belong to
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4242-401: The adult form. Their diet may also be considerably different. In the case of smaller primitive arachnids, the larval stage differs by having three instead of four pairs of legs. Larvae are frequently adapted to different environments than adults. For example, some larvae such as tadpoles live almost exclusively in aquatic environments, but can live outside water as adult frogs . By living in
4343-415: The adult. As levels of toxin vary depending on diet, some individuals are more toxic than the rest, which profit from the toxicity of those individuals, just as hoverflies benefit from mimicking well-defended wasps. One form of automimicry is where one part of an organism's body resembles another part. For example, the tails of some snakes resemble their heads; they move backwards when threatened and present
4444-444: The advantage of both organisms that share a resemblance, in which case it is mutualistic ; or it can be to the detriment of one, making it parasitic or competitive . The evolutionary convergence between groups is driven by the selective action of a dupe. Birds, for example, use sight to identify palatable insects, whilst avoiding noxious ones. Over time, palatable insects may evolve to resemble noxious ones, making them mimics and
4545-408: The back of the head, misleading predators into reacting as though they were the subject of an aggressive stare. Many insects have filamentous "tails" at the ends of their wings and patterns of markings on the wings themselves. These combine to create a "false head". This misdirects predators such as birds and jumping spiders . Spectacular examples occur in the hairstreak butterflies; when perching on
4646-462: The behaviour of the ant so that the gaster (rear part) is held raised. This presumably increases the chances of the ant being eaten by birds. Reproductive mimicry occurs when the actions of the dupe directly aid in the mimic's reproduction . This is common in plants with deceptive flowers that do not provide the reward they seem to offer and it may occur in Papua New Guinea fireflies, in which
4747-551: The caterpillar chooses the fairest leaves to lay her eggs on, so the priest lay his curse on the fairest joys". The role of caterpillars in the life stages of butterflies was badly understood. In 1679 Maria Sibylla Merian published the first volume of The Caterpillars' Marvelous Transformation and Strange Floral Food , which contained 50 illustrations and a description of insects, moths, butterflies and their larvae . An earlier popular publication on moths and butterflies, and their caterpillars, by Jan Goedart had not included eggs in
4848-428: The caterpillar is specifically adapted to the host plant under cultivation. The cotton bollworm causes enormous losses. Other species eat food crops. Caterpillars have been the target of pest control through the use of pesticides , biological control and agronomic practices. Many species have become resistant to pesticides . Bacterial toxins such as those from Bacillus thuringiensis which are evolved to affect
4949-445: The caterpillar larvae are ant larvae. This enables the larvae to be brought directly into the ant's nest. In Pouyannian mimicry, a flower mimics a female of a certain insect species, inducing the males of that species to try to copulate with the flower. This is much like aggressive mimicry in fireflies, but with a more benign outcome for the pollinator. The mechanism is named after Maurice-Alexandre Pouyanne , who first described
5050-458: The caterpillars of the Lepidoptera. Such larvae are mainly seen in the sawfly suborder. However while these larvae superficially resemble caterpillars, they can be distinguished by the presence of prolegs on every abdominal segment, an absence of crochets or hooks on the prolegs (these are present on lepidopteran caterpillars), one pair of prominent ocelli on the head capsule, and an absence of
5151-402: The cleaner, and mimics the cleaner's "dance". Once it is allowed close to the client, it attacks, biting off a piece of its fin before fleeing. Fish wounded in this fashion soon learn to distinguish mimic from model, but because the similarity is close they also become much more cautious of the model. A mechanism that does not involve any luring is seen in the zone-tailed hawk , which resembles
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#17328686845735252-524: The digression of those who have tried to prove Resurrection of the Dead from these obviously natural and comprehensible changes within the creature itself." Since then the metamorphoses of the caterpillar into a butterfly has in Western societies been associated with countless human transformations in folktales and literature. There is no process in the physical life of human beings that resembles this metamorphoses, and
5353-472: The environment such as bird droppings. Some Geometridae cover themselves in plant parts, while bagworms construct and live in a bag covered in sand, pebbles or plant material. More aggressive self-defense measures have evolved in some caterpillars. These measures include having spiny bristles or long fine hair-like setae with detachable tips that will irritate by lodging in the skin or mucous membranes. However some birds (such as cuckoos ) will swallow even
5454-406: The eyes. Once they enter such tissues, they can be difficult to extract, often exacerbating the problem as they migrate across the membrane. This becomes a particular problem in an indoor setting. The hair easily enter buildings through ventilation systems and accumulate in indoor environments because of their small size, which makes it difficult for them to be vented out. This accumulation increases
5555-478: The founder of Cartesian philosophy, and his theory on innate ideas. Descartes argued that we are distracted by urgent bodily stimuli that swamp the human mind in childhood. Descartes also theorised that inherited preconceived opinions obstruct the human perception of the truth . More recent symbolic references to caterpillars in popular media include the Mad Men season 3 episode "The Fog", in which Betty Draper has
5656-585: The genus Thaumoctopus (the mimic octopus ) are able to intentionally alter their body shape and coloration to resemble dangerous sea snakes or lionfish . In the Amazon, the helmeted woodpecker ( Dryocopus galeatus ), a rare species which lives in the Atlantic Forest of Brazil, Paraguay, and Argentina, has a similar red crest, black back, and barred underside to two larger woodpeckers: Dryocopus lineatus and Campephilus robustus . This mimicry reduces attacks on D. galeatus . Batesian mimicry occurs in
5757-401: The grave." Swammerdam, who in 1669 had demonstrated that inside a caterpillar the rudiments of the future butterfly's limbs and wings could be discerned, attacked the mystical and religious notion that the caterpillar died and the butterfly subsequently resurrected. As a militant Cartesian , Swammerdam attacked Goedart as ridiculous, and when publishing his findings he proclaimed "here we witness
5858-473: The gut of Lepidoptera have been used in sprays of bacterial spores, toxin extracts and also by incorporating genes to produce them within the host plants. These approaches are defeated over time by the evolution of resistance mechanisms in the insects. Plants evolve mechanisms of resistance to being eaten by caterpillars, including the evolution of chemical toxins and physical barriers such as hairs. Incorporating host plant resistance (HPR) through plant breeding
5959-424: The hairiest of caterpillars. Other caterpillars acquire toxins from their host plants that render them unpalatable to most of their predators. For instance, ornate moth caterpillars utilize pyrrolizidine alkaloids that they obtain from their food plants to deter predators. The most aggressive caterpillar defenses are bristles associated with venom glands. These bristles are called urticating hairs . A venom which
6060-517: The hooves and horns of dead ungulates . Caterpillars are typically voracious feeders and many of them are among the most serious of agricultural pests . In fact, many moth species are best known in their caterpillar stages because of the damage they cause to fruits and other agricultural produce, whereas the moths are obscure and do no direct harm. Conversely, various species of caterpillar are valued as sources of silk, as human or animal food, or for biological control of pest plants. The origins of
6161-407: The larvae are fed by female workers. In Ropalidia marginata (a paper wasp) the males are also capable of feeding larvae but they are much less efficient, spending more time and getting less food to the larvae. The larvae of some organisms (for example, some newts ) can become pubescent and do not develop further into the adult form. This is a type of neoteny . It is a misunderstanding that
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#17328686845736262-520: The larval form always reflects the group's evolutionary history . This could be the case, but often the larval stage has evolved secondarily, as in insects. In these cases , the larval form may differ more than the adult form from the group's common origins. Within Insects , only Endopterygotes show complete metamorphosis, including a distinct larval stage. Several classifications have been suggested by many entomologists , and following classification
6363-892: The leaf surfaces. Some caterpillars, like early instars of the tomato hornworm and tobacco hornworm , have long "whip-like" organs attached to the ends of their body. The caterpillar wiggles these organs to frighten away flies and predatory wasps. Some caterpillars can evade predators by using a silk line and dropping off from branches when disturbed. Many species thrash about violently when disturbed to scare away potential predators. One species ( Amorpha juglandis ) even makes high pitched whistles that can scare away birds. Some caterpillars obtain protection by associating themselves with ants . The Lycaenid butterflies are particularly well known for this. They communicate with their ant protectors by vibrations as well as chemical means and typically provide food rewards. Some caterpillars are gregarious ; large aggregations are believed to help in reducing
6464-497: The leaves of such toxic plants. In addition to being unaffected by the poison, the caterpillars sequester it in their body, making them highly toxic to predators. The chemicals are also carried on into the adult stages. These toxic species, such as the cinnabar moth ( Tyria jacobaeae ) and monarch ( Danaus plexippus ) caterpillars, usually advertise themselves with the danger colors of red, yellow and black, often in bright stripes (see aposematism ). Any predator that attempts to eat
6565-522: The levels of parasitization and predation. Clusters amplify the signal of aposematic coloration, and individuals may participate in group regurgitation or displays. Pine processionary ( Thaumetopoea pityocampa ) caterpillars often link into a long train to move through trees and over the ground. The head of the lead caterpillar is visible, but the other heads can appear hidden. Forest tent caterpillars cluster during periods of cold weather. Caterpillars are eaten by many animals. The European pied flycatcher
6666-437: The life stages of European moths and butterflies, because he had believed that caterpillars were generated from water. When Merian published her study of caterpillars it was still widely believed that insects were spontaneously generated. Merian's illustrations supported the findings of Francesco Redi , Marcello Malpighi and Jan Swammerdam . Butterflies were regarded as symbol for the human soul since ancient time, and also in
6767-447: The mating signals of females of the genus Photinus . Male fireflies from several different genera are attracted to these " femmes fatales ", and are captured and eaten. Each female has a repertoire of signals matching the delay and duration of the flashes of the female of the corresponding species. Some carnivorous plants may be able to increase their rate of capturing insect prey through mimicry. A different aggressive strategy
6868-417: The milk snakes and the deadly coral snakes are mimics, while the false coral snakes are the model. In Wasmannian mimicry , the mimic resembles a model that it lives along with in a nest or colony. Most of the models here are eusocial insects, principally ants. Gilbertian mimicry is bipolar, involving only two species. The potential host (or prey) drives away its parasite (or predator) by mimicking it,
6969-415: The mimic and the model benefit from the interaction, which could thus be classified as mutualism . The signal receiver also benefits by this system, despite being deceived about species identity, as it is able to generalize the pattern to potentially harmful encounters. The distinction between mimic and model that is clear in Batesian mimicry is also blurred. Where one species is scarce and another abundant,
7070-410: The mimic is sufficiently protected. Convergent evolution is an alternative explanation for why coral reef fish have come to resemble each other; the same applies to benthic marine invertebrates such as sponges and nudibranchs . In its broadest definition, mimicry can include non-living models. The specific terms masquerade and mimesis are sometimes used when the models are inanimate, and
7171-400: The mimicry's purpose is crypsis . For example, animals such as flower mantises , planthoppers , comma and geometer moth caterpillars resemble twigs, bark, leaves, bird droppings or flowers. Many animals bear eyespots , which are hypothesized to resemble the eyes of larger animals. They may not resemble any specific organism's eyes, and whether or not animals respond to them as eyes
7272-484: The mimics are not harmful, but Müllerian mimicry , where different harmful species resemble each other, is honest , as when species of wasps and of bees all have genuinely aposematic warning coloration. More complex types may be bipolar, involving only two species, such as when the model and the dupe are the same; this occurs for example in aggressive mimicry , where a predator in wolf-in-sheep's-clothing style resembles its prey, allowing it to hunt undetected. Mimicry
7373-425: The mimics, for a predator that has a bad first experience with a model tends to avoid anything that looks like it for a long time, and does not re-sample soon to see whether the initial experience was a false negative. However, if mimics become more abundant than models, then the probability of a young predator having a first experience with a mimic increases. Batesian systems are therefore most likely to be stable where
7474-418: The model is more abundant than the mimic. There are many Batesian mimics among butterflies and moths . Consul fabius and Eresia eunice imitate unpalatable Heliconius butterflies such as H. ismenius . Limenitis arthemis imitate the poisonous pipevine swallowtail ( Battus philenor ). Several palatable moths produce ultrasonic click calls to mimic unpalatable tiger moths. Octopuses of
7575-473: The most common, but there have been fatalities. Lonomia is a frequent cause of envenomation in Brazil, with 354 cases reported between 1989 and 2005. Lethality ranging up to 20% with death caused most often by intracranial hemorrhage. Caterpillar hair has also been known to cause kerato - conjunctivitis . The sharp barbs on the end of caterpillar hairs can get lodged in soft tissues and mucous membranes such as
7676-412: The nest and calls the young back. The behaviour is recognised as a form of mimicry by biologists. In 1823, Kirby and Spence, in their book An Introduction to Entomology , used the term "mimicry" informally to depict the way that the structure and coloration of some insects resembled objects in their environments: A jumping bug, very similar to the one figured by Schellenberg , also much resembles
7777-558: The noxious ones models. Models do not have to be more abundant than mimics. In the case of mutualism, each model is also a mimic; all such species can be called "co-mimics". Many harmless species such as hoverflies are Batesian mimics of strongly defended species such as wasps, while many such well-defended species form Müllerian mimicry rings of co-mimics. In the evolution of wasp-like appearance, it has been argued that insects evolve to masquerade wasps since predatory wasps do not attack each other, and that this mimetic resemblance has had
7878-411: The partial replacement of old terms with new ones. Mimicry is defensive or protective when organisms are able to avoid harmful encounters by deceiving enemies into treating them as something else. In Batesian mimicry, the mimic resembles the model, but does not have the attribute that makes it unprofitable to predators (e.g., unpalatability, or the ability to sting). In other words, a Batesian mimic
7979-400: The pattern seen in many flowers known as nectar guides . Spiders change their web day to day, which can be explained by the ability of bees to remember web patterns. Another case is where males are lured towards what seems to be a sexually receptive female. The model in this situation is the same species as the dupe. Female fireflies of the genus Photuris emit light signals that mimic
8080-424: The phenomenon. It is most common in orchids, which mimic females of the order Hymenoptera (generally bees and wasps), and may account for around 60% of pollinations. Depending on the morphology of the flower, a pollen sac called a pollinium is attached to the head or abdomen of the male. This is then transferred to the stigma of the next flower the male tries to inseminate, resulting in pollination. The mimicry
8181-456: The plant kingdom, where the chameleon vine adapts its leaf shape and colour to match that of the plant it is climbing. In Müllerian mimicry, two or more species have similar warning or aposematic signals and both share genuine anti-predation attributes (e.g. being unpalatable), as first described in Heliconius butterflies. This type of mimicry is unique in several respects. Firstly, both
8282-468: The plants on which they feed. An example of caterpillars that use camouflage for defense is the species Nemoria arizonaria . If the caterpillars hatch in the spring and feed on oak catkins they appear green. If they hatch in the summer they appear dark colored, like oak twigs. The differential development is linked to the tannin content in the diet. Caterpillars may even have spines or growths that resemble plant parts such as thorns. Some look like objects in
8383-505: The point of hatching. The butterflies avoid laying eggs near existing ones, reducing intraspecific competition between caterpillars, which are also cannibalistic , so those that lay on vacant leaves provide their offspring with a greater chance of survival. The stipules thus appear to have evolved as Gilbertian mimics of butterfly eggs, under selection pressure from these caterpillars. Browerian mimicry, named after Lincoln P. Brower and Jane Van Zandt Brower who first described it in 1967,
8484-487: The position that in spite of changes it is still possible to know something, and that Alice is the same Alice at the beginning and end of a considerable interval. When the Caterpillar asks Alice to clarify a point, the child replies "I'm afraid I can't put it more clearly... for I can't but understand it myself, to begin with, and being so many different sizes in a day is very confusing". Here Carroll satirizes René Descartes ,
8585-408: The predator first learnt to avoid a less deadly warning-coloured snake, the deadly species could profit by mimicking the less dangerous snake. Some harmless milk snakes ( Lampropeltis triangulum ), the moderately toxic false coral snakes ( Erythrolamprus aesculapii ), and the deadly coral snakes ( Micrurus ) all have a red background color with black and white/yellow rings. In this system, both
8686-435: The predator with the tail, improving their chances of escape without fatal harm. Some fishes have eyespots near their tails, and when mildly alarmed swim slowly backwards, presenting the tail as a head. Some insects such as some lycaenid butterflies have tail patterns and appendages of various degrees of sophistication that promote attacks at the rear rather than at the head. Several species of pygmy owl bear "false eyes" on
8787-542: The predator. The term Müllerian mimicry , named in his honour, has since been used for this mutualistic form of mimicry. Müller wrote that The resemblance of the genera named [ Ituna and Thyridia ] is the more worthy of notice since it occurs between insects both belonging to the group of butterflies which are protected by distastefulness. The explanation which applies in ordinary cases of [Batesian] mimicry—and no other has, so far as I know, been offered—cannot obtain for this imitation among protected species. Mimicry
8888-425: The primary reason for this unusual locomotion is the elimination of nearly all the prolegs except the clasper on the terminal segment. Caterpillars have soft bodies that can grow rapidly between moults. Their size varies between species and instars (moults) from as small as 1 millimetre (0.039 in) up to 14 centimetres (5.5 in). Some larvae of the order Hymenoptera (ants, bees, and wasps) can appear like
8989-435: The rare species can be said to be the mimic. When both are present in similar numbers, however, it makes more sense to speak of each as a co-mimic than of distinct 'mimic' and 'model' species, as their warning signals tend to converge. Also, the mimetic species may exist on a continuum from harmless to highly noxious, so Batesian mimicry grades smoothly into Müllerian convergence. Emsleyan or Mertensian mimicry describes
9090-507: The reverse of host-parasite aggressive mimicry. It was coined by Pasteur as a phrase for such rare mimicry systems, and is named after the American ecologist Lawrence E. Gilbert who described it in 1975. The classical instance of Gilbertian mimicry is in the plant genus Passiflora , which is grazed by the micropredator larvae of some Heliconius butterflies. The host plants have evolved stipules that mimic mature Heliconius eggs near
9191-615: The risk of human contact in indoor environments. Caterpillars are a food source in some cultures. For example, in South Africa mopane worms are eaten by the bushmen , and in China silkworms are considered a delicacy. In the Old Testament of the Bible caterpillars are feared as pests that devour crops. They are part of the "pestilence, blasting, mildew, locust" because of their association with
9292-432: The roles are taken by just two species, the system is called bipolar. Mimicry evolves if a dupe (such as a predator) perceives a mimic (such as a palatable prey) as a model (the organism it resembles), and is deceived to change its behaviour to the mimic's selective advantage. The resemblances can be via any sensory modality, including any combination of visual, acoustic, chemical, tactile, or electric. Mimicry may be to
9393-468: The signal of Pteroptyx effulgens is used by P. tarsalis to form aggregations to attract females. Other forms of mimicry have a reproductive component, such as Vavilovian mimicry involving seeds, vocal mimicry in birds, and aggressive and Batesian mimicry in brood parasite-host systems. Bakerian mimicry, named after Herbert G. Baker , is a form of automimicry where female flowers mimic male flowers of their own species, cheating pollinators out of
9494-450: The strategy resembles a wolf in sheep's clothing , though no conscious deceptive intent is involved. The mimic may resemble the prey or host itself, or another organism that does not threaten the prey or host. Several spiders use aggressive mimicry to lure prey. Species such as the silver argiope ( Argiope argentata ) employ prominent patterns in the middle of their webs, such as zigzags. These may reflect ultraviolet light, and mimic
9595-507: The symbol of the caterpillar tends to depict a psychic transformation of a human. As such the caterpillar has in the Christian tradition become a metaphor for being "born again". Famously, in Lewis Carroll 's Alice's Adventures in Wonderland a caterpillar asks Alice "Who are you?". When Alice comments on the caterpillar's inevitable transformation into a butterfly, the caterpillar champions
9696-508: The unusual case where a deadly prey mimics a less dangerous species. It was first proposed by M. G. Emsley in 1966 as a possible explanation for how a predator can learn to avoid a very dangerous aposematic animal, such as a coral snake , when the predator is very likely to die, making learning unlikely. The theory was developed by the German biologist Wolfgang Wickler who named it after the German herpetologist Robert Mertens . The scenario
9797-503: The upside-down Y-shaped suture on the front of the head. Lepidopteran caterpillars can be differentiated from sawfly larvae by: In 2019 , a geometrid moth caterpillar dating back to the Eocene epoch , approximately 44 million years ago , was found preserved in Baltic amber . It was described under Eogeometer vadens . Previously, another fossil dating back approximately 125 million years
9898-736: The useful side-effect of deterring vertebrate predators. Mimicry can result in an evolutionary arms race if mimicry negatively affects the model, in which case the model can evolve a different appearance from the mimic. Mimics may have different models for different life cycle stages, or they may be polymorphic , with different individuals imitating different models, as occurs in Heliconius butterflies. Models tend to be relatively closely related to their mimics, but mimicry can be of vastly different species, for example when spiders mimic ants. Most known mimics are insects, though many other examples including vertebrates , plants, and fungi exist. It
9999-531: The word mimicry dates to 1637. It derives from the Greek term mimetikos , "imitative", in turn from mimetos , the verbal adjective of mimeisthai , "to imitate". "Mimicry" was first used in zoology by the English entomologists William Kirby and William Spence in 1823. Originally used to describe people, "mimetic" was used in zoology from 1851. Aristotle wrote in his History of Animals that partridges use
10100-453: The word "caterpillar" date from the early 16th century. They derive from Middle English catirpel , catirpeller , probably an alteration of Old North French catepelose : cate , cat (from Latin cattus ) + pelose , hairy (from Latin pilōsus ). The inchworm, or looper caterpillars from the family Geometridae are so named because of the way they move, appearing to measure the earth (the word geometrid means earth-measurer in Greek );
10201-479: Was found in Lebanese amber . Many animals feed on caterpillars as they are rich in protein. As a result, caterpillars have evolved various means of defense. Caterpillars have evolved defenses against physical conditions such as cold, hot or dry environmental conditions. Some Arctic species like Gynaephora groenlandica have special basking and aggregation behaviours apart from physiological adaptations to remain in
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