The Phasmatodea (also known as Phasmida or Phasmatoptera ) is a sequence of insects, whose members are known as stick insects b> in Europe and Australasia; bug-stick , walking stick or bug stick in the United States and Canada; or as phasmids , ghost insects or leaf insects (generally the Phylliidae family). The name of this group is from Ancient Greek ????? phasma , which means appearance or ghost, referring to the similarity of many species with sticks or leaves. Their natural camouflage makes them difficult for predators to detect, but many species have secondary defensive lines in the form of a terrific display, thorns or poisonous secretions. The genus Phobaeticus includes the world's longest insect.
Members of the order are found in all continents except Antarctica, but they are most abundant in the tropics and subtropics. They are herbivores with many species living under a tree canopy. They have a three-stage hemimetabolous life cycle: egg, nymph and adult. Many phasmids are parthenogenic, and do not require fertilized eggs for the female offspring to be produced. In warmer climates, they can multiply throughout the year; in temperate regions, females lay eggs in autumn before dying, and new generations hatch in spring. Some species have wings and can spread by flying, while others are more limited.
Video Phasmatodea
Description
Phasmids can be relatively large, ranging from 1.5 cm (0.6 inches) to over 30 cm (12 inches) in length. Women of the genus Phobaeticus are the world's longest insects, measuring up to 56.7 cm (22.3 inches) in total length in the case of Phobaeticus chani , including the outstretched legs. The heaviest species of phasmid is probably Heteropteryx dilatata , females weighing up to 65 g (2.3 oz).
Some phasmids have shapes like cylindrical sticks, while others have leaf-like shapes. Many species without wings, or have reduced the wings. Long chest on winged species, as it houses the flying muscles, and is usually shorter in wingless form. If present, the first pair of wings are narrow and cornified, while the rear wings are wide, with straight veins along the length and multiple cross-vein. The body is often further modified to resemble vegetation, with the back resembling leaf veins, tubercles resembling bark, and other forms of camouflage. Some species, such as Carausius morosus , are even able to change their pigmentation to match their environment. Mouth project out of the head. Chew uniform mandible throughout the species. The legs are usually long and slender, and some species may perform limb muscomi (additional release). Phasmid has a long, slender antenna, during or longer than the rest of the body in some species.
All phasmids have compound eyes, but oselus (light sensitive organ) is found only in some winged men. Phasmid has an impressive visual system that allows them to experience significant detail even in dim conditions, which suits their lifestyle at night. They are born with small compound eyes with a limited number of facets. As the phaside grows through the consecutive mole, the number of facets in each eye increases with the number of photoreceptor cells. Adult eye sensitivity is at least ten times that of nymphs in the first instar (developmental stage). As the eye grows more complex, the mechanisms for adapting to dark/bright changes are also enhanced: the eye in dark conditions indicates fewer pigment screening, which will block light, than during the daytime, and changes in the width of the retinal lining to adapt the available light changes significantly more prominent in adults. However, the larger size of adult eye insects make them more susceptible to radiation damage. This explains why individuals who grow up are mostly active at night. The less light sensitivity of the newly emerging insects helps them to escape from the leaf litter where they hatch and move upwards into the brighter foliage. Young stick insects are diurnal feeders (daytime) and move freely, extending their feeding range.
Insect sticks have two types of pads on their feet: sticky "foot pads" and "heel pads" non-stick a bit further up their legs. The heel pads are covered in microscopic hair that creates strong friction at low pressure, enabling them to grasp without having to peel energetically off the surface at each step. Sticky foot pads are used to provide additional grip when climbing but not used on flat surfaces.
Maps Phasmatodea
Distribution
Phasmatodea can be found all over the world except Antarctica and Patagonia. They are mostly in the tropics and subtropics. The greatest diversity is found in Southeast Asia and South America, followed by Australia, Central America, and the southern United States. More than 300 species are known from the island of Borneo, making it the richest place in the world for Phasmatodea.
Phasmatodea is recognized as harmful to forests and shade trees with defoliation. Didymuria violescens , Podacanthus wilkinsoni and Ctenomorphodes tessulatus in Australia, Diapheromera femorata Graeffea crouani in coconut plantations in the South Pacific all occur in important economic epidemics. Indeed, in South America, as well as in Michigan and Wisconsin, sticks are a significant problem in parks and recreational areas where it consumes leaves from oaks and other hardwoods. Outbreaks of sticks, Diapheromera femorata, have occurred in the Ouachita Mountains in Arkansas and Oklahoma. Insects eat all the leaves. In case of severe outbreaks, the entire tree stand may be completely destroyed. Sustained defoliation for several years often leads to the death of trees. Fortunately for control efforts, because insects can not fly, infestations are usually contained within a radius of several hundred meters. However, damage to parks in the area is often expensive. Control measures in cases of infestation usually involve chemical pesticides; Fire ground effectively kills eggs but has obvious disadvantages. In New South Wales, research has been conducted into the feasibility of controlling stick insects using natural enemies such as the parasitic wasp ( Myrmecomimesis spp.).
Antipredator Adaptation
Phasmatodea species exhibit defense mechanisms from predators that prevent attacks from occurring in the first place (primary defense), and defense deployed after the attack has started (secondary defense).
The most easily identifiable defense mechanism with Phasmatodea is camouflage, in the form of plant mimicry. Most of the phasmids are known to replicate the shapes of sticks and leaves, and the bodies of several species (such as Pseudodiacantha macklotti and Bactrododema centaurum) are covered in moss or lichenous grown that complement their disguises. Stay completely silent improve their disguises. Some species have the ability to change color as their environment shifts ( Bostra scabrinota , Timema californica ). In further behavioral adaptations to complement crypsis, a number of species perform a rocking motion in which the body swayes from side to side; this is considered to imitate the movement of leaves or twigs that sway in the wind. Another method used stick insects to avoid predation and resemble twigs is by entering a cataleptic state, in which the insect adopts a rigid and immobile posture that can be maintained for long periods of time. Adult dinner habits also help Phasmatodea to stay hidden from predators.
In a seemingly opposite defense method, many Phasmatodea species, attempting to surprise the disturbing predators by emitting the usual bright colors that are usually hidden, and making loud noises. When plagued in a branch or foliage, some species, while throwing themselves into the bush to escape, will open their wings for a moment during free fall to display the bright colors that disappear when the insects land. Others will maintain their display for up to 20 minutes, hoping to scare off predators and convey the appearance of a larger size. Some, such as Pterinoxylus spinulosus , accompany the visual appearance with sounds created by rubbing the wing parts.
Some species, such as the young nymphs of Extratosoma tiaratum, have been observed to bend the upper abdomen above the body and the head resembles ants or scorpions in mimicry action, another defense mechanism by which the insects avoid becoming prey. Eggs from some species such as Diapheromera femorata have fleshy projections that resemble elaiosomes (the meat structure that sometimes attaches to the seed) that attracts the ants. When the eggs have been brought to the colony, the ants feed the elaiosome into the larvae and the phasmid egg develops in the nesting niches in a protected environment.
When threatened, some phasmids are equipped with femoral spines on the feet of metathoracic ( Oncotophasma martini , Eurycantha calcarata , Eurycantha horrida , Diapheromera veliei Diapheromera covilleae responds by pouting the stomach up and repeatedly swinging both legs, catching the threat. If the threat is caught, the thorns can draw blood and cause tremendous pain.
Some species are equipped with a pair of glands on the front edge (front) of the prothorax that allows insects to release defense secretions, including chemical compounds with various effects: some produce different odors, and others cause a stinging, burning sensation in the eyes and mouth of a predator. These sprays often contain sharp-smelling volatile metabolites, previously thought to be concentrated in insects from plant-based sources. However, it now seems more likely that insects produce their own defense chemicals. In addition, the chemistry of defensive sprays from at least one species, buprestoides Anisomorpha , has been shown to vary based on the life stage of the insect or the particular population that it is part of. This chemical spray variation also matches the specific regional color shapes in Florida's population, with different variants having different behaviors. The spray of one species, Megacrania nigrosulfurea , is used as a treatment for skin infections by a tribe in Papua New Guinea because of its antibacterial content. Some species use short-range defense shortcomings, in which individuals bleed reflexively through the joints of their feet and seams of the exoskeleton when disturbed, allowing blood (hemolymph), which contains unpleasant additives, to prevent predators. Another way is to regurgitate their entrails when harassed, repelling potential predators.
Life cycle
The life cycle of insect sticks begins when the females store their eggs through one of these oviposition methods: it will flick its eggs to the ground by ovipositor movement or all of its stomach, carefully placing the eggs in the host's axis, bury them in a small hole in soil, or stick the eggs to the substrate, usually the stems or leaves of the food plant. A female females lay eggs from 100 to 1,200 eggs after mating, depending on the species.
Many species of phasmids are parthenogenic, meaning the female spawns without the need to mate with males to produce offspring. Eggs from virgin mothers are fully female and hatch into nymphs which are exact copies of their mothers. The stick of an insect species that is a hybridized product usually obliges parthenogen, but non-hybrids are a participative parthenogens, meaning they retain the ability to mate and their sexual behavior depending on the presence and abundance of men.
Phasmatodea eggs resemble seeds in shape and size, and have a hard shell. They have a cap-like structure called the anterior polar operculum, from which the nymph appears at the time of hatching. Eggs vary within the time period before hatching that varies from 13 to more than 70 days, with an average of about 20 to 30 days. Some species, especially those from temperate climates, experience diapause, where development is delayed during the winter months. Diapause is initiated by a short-term day effect on laying adults or can be determined genetically. Diapause is damaged by exposure to winter cold, causing eggs to hatch during the following spring. Among the important economic species such as Diapheromera femorata, diapause resulted in the development of a two-year outbreak cycle.
Many egg species contain fatty and fat kapok that covers the operculum. This structure attracts ants because of their resemblance to the elaiosome of some plant seeds sought by food sources for ant larvae, and usually contributes to ensuring the dispersion of seed by ants, a form of plant-called mutualism called myrmecochory. The ants take the eggs into their underground nests and can move the capitulum to feed their larvae without damaging the phasmid embryo. There, the eggs hatch and the young nymph, which originally resembled ants (another example of mimicry between Phasmatodea), eventually emerged from the nest and climbed the nearby tree to a safe place in the foliage. The stick insect eggs have a layer of calcium oxalate that makes them endure unscathed in the bird's digestive tract. It has been suggested that birds may have a role in the spread of insect species of parthenogenetic sticks, especially to the islands.
The life cycle of Phasmatodea is hemimetabolous, continuing through a series of several nukmin instars. As with hatching, if a nymph is caught in a cast skin wrap or an egg capsule, it may die because it can not free itself. Once it appears, the nymph will eat the skin of the cast. Adulthood is achieved for most species after several months and many molts. Phasmatodea age varies by species, but ranges from a few months to three years.
Ecology
Phasmids are herbivores, feeding mostly on tree leaves and shrubs, and striking components of many neotropical systems (South America). Phasmatodea has been postulated as a dominant light slit herbivore there. Their role in forest ecosystems is considered important by many scientists, who emphasize the importance of light gaps in maintaining succession and resilience in climactic forests. The presence of phasmid lowers the net production of early succession plants by consuming it and then enriching the soil with a bowel movement. This allows succession crops too late to become established and encourage recycling of tropical forests.
Phasmatodea is recognized as harmful to forests and shade trees with defoliation. Didymuria violescens , Podacanthus wilkinsoni and Ctenomorphodes tessulatus in Australia, Diapheromera femorata Graeffea crouani in coconut plantations in the South Pacific all occur in important economic epidemics. Indeed, in South America, as well as in Michigan and Wisconsin, sticks are a significant problem in parks and recreational areas where it consumes leaves from oaks and other hardwoods. Outbreaks of sticks, Diapheromera femorata, have occurred in the Ouachita Mountains in Arkansas and Oklahoma. Insects eat all the leaves. In case of severe outbreaks, the entire tree stand may be completely destroyed. Sustained defoliation for several years often leads to the death of trees. Fortunately for control efforts, because insects can not fly, infestations are usually contained within a radius of several hundred meters. However, damage to parks in the area is often expensive. Control measures in cases of infestation usually involve chemical pesticides; Fire ground effectively kills eggs but has obvious disadvantages. In New South Wales, research has been conducted into the feasibility of controlling stick insects using natural enemies such as the parasitic wasp ( Myrmecomimesis spp.).
Taxonomy
The classification of Phasmatodea is complex and the relationship between its members is poorly understood. Furthermore, there is a lot of confusion on behalf of ordinal. Phasmida is preferred by many authors, though it is not properly formed; Phasmatodea is well established, and widely accepted.
Phasmatodea sequences are sometimes considered to be related to other orders, including Blattodea, Mantodea, Notoptera and Dermaptera, but uncertain affiliations and groupings (sometimes referred to as "Orthopteroidea") may be paraphyletic (and have no common ancestors) and are therefore invalid in traditional boundaries (a collection of attributes that all members have). Phasmatodea, formerly regarded as the suborder of Orthoptera, is now treated as a separate order. Anatomical features separate them as monophyletic groups (derived from common ancestors) from Orthoptera. One is an example among all Phasmatodea species of a pair of exocrine glands in the prothorax used for defense. Another is the presence of a specially formed sclerite (hardened plate) called a vomer that allows males to clamp a female during mating.
Orders are divided into two, or sometimes three, subordos. The most common divisions are into the suborder group Anareolatae and Areolatae, which are distinguished according to whether the insect has a concave areola, or a circular area, at the bottom of the middle and back apex of the tibiae (Areolate) or not (Anareolate). But the phylogenetic relationship (evolution) between different groups can not be solved well. The monophyly of Anareolatae has been questioned and egg morphology can be a better basis for classification. The alternative is to divide the Phasmatodea into three suborder Agathemerodea (1 genus and 8 species), Timematodea (1 genus and 21 species) and Verophasmatodea for the remaining taxa. This division, however, is not fully supported by molecular studies, which restores Agathemerodea as lodged within Verophasmatodea rather than being the sister group of the latter group. More than 3,000 species have been described, with many yet to be explained both in museum collections and in the wild.
Phasmatodea fossils are rare, either as adults or as eggs; the isolated wing is the most commonly discovered part. The modern group is monophyletic. Some of the Mesozoic family seem to be associated with phasmid, and generally but not universally agreed to be a stem-stick insect. One species is known (as a retraction) of the Brazilian fossilized Brazilian productive Crato Formation, Cretophasma araripensis (Aerophasmatidae). Other members of Aerophasmatidae are known from the Jurassic of England, Germany and Kazakhstan. Phasmids are rarely found in amber, but Gallophasma longipalpis was discovered in 2010 in the Early Eocene of France. Engel, Wang and Alqarni (2016) describe members of the Phasmatidae family of sensuous letters of Burmese amet Cretaceous (Cenomanian), Echinosomiscus primoticus . According to the authors, the discovery of E. primoticus provides the first reliable evidence for Euphasmatodea (a clan containing all living phasmatodesan except members of the genus Timema ) and even Neophasmatodea (a clause containing all members of Euphasmatodea who are alive except aschiphasmatids) at Cenomanian.
The earliest insect fossil (Phylliinae) is Eophyllium messelensis of the 47-million-year-old Eocene of Messel, Germany. In vague size and body shape (like leaves), very much like the extant species, shows that group behavior has changed little since then.
Famous species
One Australian species, the Lord Howe Island stick insect, is now listed as endangered. It is believed to be extinct until rediscovery on a rock known as the Ball's Pyramid. An attempt is being made in Australia to raise this species in captivity.
The most famous of these stick insects are Indian stick insects or labs ( Carausius morosus ). These insects grow about 10 cm (4 inches) and reproduce parthenogenically, and although males have been recorded, they are rare.
Fossils of the extinct genera and species Eoprephasma hichensi have been found from Ypresian age sediments in the US, Washington and British Columbia, Canada states. This species is one of the youngest members of the parent group phasmatodean Susumanioidea.
Phasmid in Europe
In Europe there are 17 species of stick insects described, belonging to the genus Bacillus , Clonopsis , Leptynia y Pijnackeria . There are also several other species that live in Europe but are introduced, as for example with some species of Acanthoxyla , native to New Zealand but present in southern England.
In the Iberian Peninsula currently described 13 species and several subspecies. The life cycle is annual, living only during the hottest months (especially the sex of Leptynia and Pijnackeria), which usually means late spring to early fall.
Behavior
Insect sticks, like a worship mantis, show a rocking behavior in which insects make rhythmic, repetitive, and spinning movements. A common interpretation of this behavioral function is to increase crypsis by mimicking the vegetation that moves in the wind. However, these movements may be most important in enabling insects to distinguish objects from backgrounds with relative motion. This generally sedentary rocking motion can replace flying or running as a source of relative motion to help them distinguish objects in the foreground.
The marriage behavior in Phasmatodea is very impressive because of the incredibly long couples duration. A note among insects, the Necroscia sparaxes stick insect, found in India, is sometimes combined for 79 days at a time. It is not uncommon for this species to consider marriage postures for days or weeks, and among some species ( Diapheromera veliei and D. covilleae ), the couple may last three to 136 hours in captivity.
The exaggerated display of aggression between men over the pair suggests that extended couples may have evolved to keep females from sperm competition. The battle between competing males has been observed in species D. veiliei and D. covilleae . During these meetings, the challenger approach causes an existing partner to manipulate a woman's stomach, which she has grasped by means of a clasping organ, or vomer, down on her own to block the place of attachment. Sometimes, the empress will attack competitors with middle femora, which is equipped with an enlarged spine bound to both sexes that can draw the opponent's blood when they are flexed against the body to pierce the integument. Usually, a strong grip on a woman's stomach and a blow to an intruder is enough to block unwanted competition, but sometimes competitors have been observed using cunning tactics to inseminate women. While the first couple engages in feeding and is forced to vacate the dorsal position, the intruder can grasp the woman's abdomen and insert her genitals. If he is found, men will enter into battle where they lean back, both gripping the woman's belly, and freely hanging, engaging in a quick blow and sweeping with their front paws in a manner similar to boxing. Usually, when the intruder gets attachment to a woman's abdomen, these conflicts result in the displacement of the original pair.
Long couples have also been described in terms of defense alliances. When split together, the couple is heavier to be handled by predators. Also, chemical defenses (secretions, reflex bleeding, regurgitation) of individual stick insects are enhanced when the two are paired. Females survive from predatory attacks significantly better when in pairs, mainly because the male dorsal position works well as a shield. This may indicate that manipulation by women occurs: if women receive ejaculation at a slow rate, for example, men are forced to stay within copulo longer and the chances of female survival are increased. Also, evolution can be easily favored by men who remain attached to their females longer, because women are often less abundant than men and represent valuable gifts, so for the lucky man, even the sacrifice of his own life to defend his offspring by women may be useful. Sexual dimorphism in species, in which women are usually significantly larger than men, may have evolved because of the fitness gains that males may attach to women, thus blocking competitors, without impeding their movements.
Certain phasmatodesa, such as Buprestoides Anisomorpha, sometimes form an aggregation. These insects have been observed to gather during the day at a hidden location, to go apart at night to find food, and return to their refuge before dawn. Such behavior is little studied, and how insects find their way back is unknown.
In human culture
Insect sticks are often kept in captivity: nearly 300 species have been preserved in the laboratory or as pets. The most commonly kept are Indian stick insects (or laboratories), Carausus morosus , which eats vegetables such as lettuce.
Botanical illustrator Marianne North (1830-1890) painted the insect leaves and sticks he saw during his journey in the 1870s.
The tribe in Sarawak eat their phasmids and eggs.
Research has been done to analyze the method of walking stick insects and apply this to the engineering of a six foot walk robot. Instead of a centralized control system, it seems that each leg of the phasmid operates independently.
In Australia many types of stick insects kept as pets include Strong, Goliath, Spiny and Children's.
References
External links
- Phasmid Study Group
- Phasmatodea.com
- Phasmida Species Files
- New Zealand Insect Stick Web Site
- ASPER: Lesser Antilles and French stick insectects
- Phasmid gut
Source of the article : Wikipedia
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