Beetles are a group of insects that form the order Coleoptera, in the superorder Endopterygota. Their front pair of wings are hardened into wing-cases, distinguishing them from most other insects; the Coleoptera, with about 400,000 species, is the largest of all orders, constituting 40% of described insects and 25% of all known animal life-forms. The largest of all families, the Curculionidae with some 70,000 member species, belongs to this order. Found in every habitat except the sea and the polar regions, they interact with their ecosystems in several ways: beetles feed on plants and fungi, break down animal and plant debris, eat other invertebrates; some species are serious agricultural pests, such as the Colorado potato beetle, while others such as Coccinellidae eat aphids, scale insects and other plant-sucking insects that damage crops. Beetles have a hard exoskeleton including the elytra, though some such as the rove beetles have short elytra while blister beetles have softer elytra; the general anatomy of a beetle is quite uniform and typical of insects, although there are several examples of novelty, such as adaptations in water beetles which trap air bubbles under the elytra for use while diving.
Beetles are endopterygotes, which means that they undergo complete metamorphosis, with a series of conspicuous and abrupt changes in body structure between hatching and becoming adult after a immobile pupal stage. Some, such as stag beetles, have a marked sexual dimorphism, the males possessing enormously enlarged mandibles which they use to fight other males. Many beetles are aposematic, with bright colours and patterns warning of their toxicity, while others are harmless Batesian mimics of such insects. Many beetles, including those that live in sandy places, have effective camouflage. Beetles are prominent in human culture, from the sacred scarabs of ancient Egypt to beetlewing art and use as pets or fighting insects for entertainment and gambling. Many beetle groups are brightly and attractively coloured making them objects of collection and decorative displays. Over 300 species are used as food as larvae. However, the major impact of beetles on human life is as agricultural and horticultural pests.
Serious pests include the boll weevil of cotton, the Colorado potato beetle, the coconut hispine beetle, the mountain pine beetle. Most beetles, however, do not cause economic damage and many, such as the lady beetles and dung beetles are beneficial by helping to control insect pests; the name of the taxonomic order, comes from the Greek koleopteros, given to the group by Aristotle for their elytra, hardened shield-like forewings, from koleos and pteron, wing. The English name beetle comes from the Old English word bitela, little biter, related to bītan, leading to Middle English betylle. Another Old English name for beetle is ċeafor, used in names such as cockchafer, from the Proto-Germanic *kebrô. Beetles are by far the largest order of insects: the 400,000 species make up about 40% of all insect species so far described, about 25% of all animals. A 2015 study provided four independent estimates of the total number of beetle species, giving a mean estimate of some 1.5 million with a "surprisingly narrow range" spanning all four estimates from a minimum of 0.9 to a maximum of 2.1 million beetle species.
The four estimates made use of host-specificity relationships, ratios with other taxa, plant:beetle ratios, extrapolations based on body size by year of description. Beetles are found in nearly all habitats, including freshwater and coastal habitats, wherever vegetative foliage is found, from trees and their bark to flowers and underground near roots - inside plants in galls, in every plant tissue, including dead or decaying ones; the heaviest beetle, indeed the heaviest insect stage, is the larva of the goliath beetle, Goliathus goliatus, which can attain a mass of at least 115 g and a length of 11.5 cm. Adult male goliath beetles are the heaviest beetle in its adult stage, weighing 70–100 g and measuring up to 11 cm. Adult elephant beetles, Megasoma elephas and Megasoma actaeon reach 50 g and 10 cm; the longest beetle is the Hercules beetle Dynastes hercules, with a maximum overall length of at least 16.7 cm including the long pronotal horn. The smallest recorded beetle and the smallest free-living insect, is the featherwing beetle Scydosella musawasensis which may measure as little as 325 µm in length.
The oldest known fossil insect that unequivocally resembles a Coleopteran is from the Lower Permian Period about 270 million years ago, though these members of the family Tshekardocoleidae have 13-segmented antennae, elytra with more developed venation and more irregular longitudinal ribbing, abdomen and ovipositor extending beyond the apex of the elytra. In the Permian–Triassic extinction event at the end of the Permian, some 30% of all insect species became extinct, so the fossil record of insects only includes beetles from the Lower Triassic 220 mya. Around this time, during the Late Triassic, fungus-feeding species such as Cupedidae appear in the fossil record. In the stages of the Upper Triassic, alga-feeding insects such as Triaplidae and Hydrophilidae begin to appear, alongside predatory water beetles; the first weevils, including the Obrienidae, appear alongside the first rove beetles, which resemb
Tropidophis, common name wood snake or West Indian wood snake, is a genus of dwarf boas endemic to the West Indies and South America. 17 species are recognized. Adults grow to between 60 cm in total length, they are secretive and predominately terrestrial, found in a variety of natural habitats, including rain forest, pine woods and scrub, as well as in the vicinity of human habitation. They have a peculiar defensive habit of expelling blood from the mouth and eyes when disturbed; some species change colour over the course of the day. Despite their small size and secretive nature, some species may be susceptible to extirpation due to habitat alteration and introduced feral animals; the Navassa Island dwarf boa, T. bucculentus, has not been seen for 100 years and is believed to be extinct. Found in the West Indies, Brazil and Ecuador. *) Not including the nominate subspeciesT) Type speciesThe Reptile Database includes some further species: *) Not including the nominate subspecies List of tropidophiid species and subspecies Tropidophiidae by common name Tropidophiidae by taxonomic synonyms Bibron G.
In: de la Sagra R. Historia fisica, politica y natural de la isla de Cuba. Segunda parte historia natural. Tomo IV. Reptiles y peces. Paris: Bertrand. 255 pp. + Plates I-V... Boulenger GA. Catalogue of the Snakes in the British Museum. Volume I. Containing the Families... Boidæ... London: Trustees of the British Museum.. Xiii + 448 pp. + Plates I-XXVIII.. Freiberg M. Snakes of South America. Hong Kong: T. F. H. Publications. 189 pp. ISBN 0-87666-912-7.. Schwartz A, Thomas R. A Check-list of West Indian Amphibians and Reptiles. Carnegie Museum of Natural History Special Publication No. 1. Pittsburgh, Pennsylvania: Carnegie Museum of Natural History. 216 pp.. Tropidophis at the Reptarium.cz Reptile Database. Accessed 29 August 2007
Horned lizards known as horny toads or horntoads, are a genus of North American lizards and the type genus of the family Phrynosomatidae. The common names refer directly to their flattened, rounded body and blunt snout; the genus name Phrynosoma means "toad-bodied". In common with large true frogs and toads, horned lizards tend to move sluggishly, making them easy to catch, they are adapted to semi-arid areas. The spines on the lizard's back and sides are made from modified reptile scales which prevent the water loss through the skin, whereas the horns on the head are true horns. Of the 22 species of horned lizards, 15 are native to the United States; the largest-bodied and most distributed of the US species is the Texas horned lizard. Horned lizards use a wide variety of means to avoid predation, their coloration serves as camouflage. When threatened, their first defense is to remain still to avoid detection. If approached too they run in short bursts and stop abruptly to confuse the predator's visual acuity.
If this fails, they puff up their bodies to cause them to appear more horned and larger, so that they are more difficult to swallow. At least eight species are able to squirt an aimed stream of blood from the corners of the eyes for a distance of up to 5 feet, they do this by restricting the blood flow leaving the head, thereby increasing blood pressure and rupturing tiny vessels around the eyelids. The blood not only confuses predators, but tastes foul to canine and feline predators, it appears to have no effect against predatory birds. Only three related species are known to be unable to squirt blood. While previous thought held that compounds were added to the blood from glands in the ocular sinus cavity, current research has shown that the chemical compounds that make up the defense are in the circulating blood, it is possible. The blood-squirting mechanism increases survival after contact with canine predators. Ocular autohemorrhaging has been documented in other lizards, which suggests blood-squirting could have evolved from a less extreme defense in the ancestral branch of the genus.
Recent phylogenic research supports this claim, so it appears as though the species incapable of squirting blood have lost the adaptation for reasons yet unstudied. To avoid being picked up by the head or neck, a horned lizard ducks or elevates its head and orients its cranial horns straight up, or back. If a predator tries to take it by the body, the lizard drives that side of its body down into the ground so the predator cannot get its lower jaw underneath. A University of Texas publication notes that horned lizard populations continue to disappear throughout the southwest despite protective legislation; the Texas horned lizard has disappeared from half of its geographic range. Population declines are attributed to loss of habitat, human eradication of the ant populations upon which the lizards prey, displacement of native ant populations by invading fire ants, predation by domestic dogs and cats. In 2014, the Center for Biological Diversity in Tucson, Arizona petitioned the Oklahoma Department of Wildlife Conservation to have the Texas horned lizard put on the endangered species list due to the massive declines of its population in Oklahoma, where it was once plentiful.
The Center said it may seek protection for the animal on a Federal level. The following 22 species are recognized as being valid, three species of which have recognized subspecies. Giant horned lizard, Phrynosoma asio Cope, 1864 Phrynosoma bauri Montanucci, 2015 Phrynosoma blainvillii Gray, 1839 Short-tailed horned lizard, Phrynosoma braconnieri A. H. A. Duméril, 1870 Phrynosoma brevirostris Cedros Island horned lizard, Phrynosoma cerroense Stejneger, 1893 Texas horned lizard, Phrynosoma cornutum Coast horned lizard, Phrynosoma coronatum Cape horned lizard, P. c. coronatum California horned lizard, P. c. frontale Van Denburgh, 1894 Central peninsular horned lizard, P. c. jamesi Schmidt, 1922Phrynosoma diminutum Montanucci, 2015 Ditmars' horned lizard or rock horned lizard, Phrynosoma ditmarsi Stejneger, 1906 Pygmy short-horned lizard, Phrynosoma douglasii Phrynosoma goodei Stejneger, 1893 Greater short-horned lizard, Phrynosoma hernandesi Girard, 1858 Flat-tail horned lizard, Phrynosoma mcallii Roundtail horned lizard, Phrynosoma modestum Girard, 1852 Mexican Plateau horned lizard or Chihuahua Desert horned lizard, Phrynosoma orbiculare P. o. bradti Horowitz, 1955 P. o. cortezii P. o. dugesii P. o. orbiculare P. o. orientale Horowitz, 1955Phrynosoma ornatissimum Desert horned lizard, Phrynosoma platyrhinos Girard, 1852Southern desert horned lizard, P. p. calidiarum Northern desert horned lizard, P. p. platyrhinos Girard, 1852Phrynosoma sherbrookei Nieto-Montes de Oca et al. 2014 Regal horned lizard, Phrynosoma solare Gray, 1845 Mexican horned lizard, Phrynosoma taurus Dugès, 1873 Gulf Coast
Orthoptera is an order of insects that comprises the grasshoppers and crickets, including related insects such as the katydids and wetas. The order is subdivided into two suborders: Caelifera – grasshoppers and close relatives. More than 20,000 species are distributed worldwide; the insects in the order have incomplete metamorphosis, produce sound by rubbing their wings against each other or their legs, the wings or legs containing rows of corrugated bumps. The tympanum or ear is located in the front tibia in crickets, mole crickets, katydids, on the first abdominal segment in the grasshoppers and locusts; these organisms use vibrations to locate other individuals. Grasshoppers and other orthopterans are able to fold their wings, they are grouped with similar "Orthopteroid" insect orders; the name is derived from the Greek ὀρθός orthos meaning "straight" and πτερόν pteron meaning "wing". Orthopterans have a cylindrical body, with elongated hindlegs and musculature adapted for jumping, they have mandibulate mouthparts for biting and chewing and large compound eyes, may or may not have ocelli, depending on the species.
The antennae have multiple joints and filiform type, are of variable length. The first and third segments on the thorax are larger, they have two pairs of wings. The forewings, or tegmina, are narrower than the hindwings and hardened at the base, while the hindwing is membranous, with straight veins and numerous cross-veins. At rest, the hindwings are held; the final two to three segments of the abdomen are reduced, have single-segmented cerci. and their wing type is tegmina. Orthopterans have incomplete metamorphosis; the use of sound is crucial in courtship, most species have distinct songs. Most grasshoppers lay their eggs on vegetation; the eggs hatch and the young nymphs resemble adults, but lack wings and at this stage are called'hoppers'. They may also have a radically different coloration from the adults. Through successive moults, the nymphs develop wings until their final moult into a mature adult with developed wings; the number of moults varies between species. The Orthoptera is divided into two suborders and Ensifera which have been shown to be monophyletic.
Taxonomists classify members of the Caelifera and Ensifera into infraorders and superfamilies as follows: Suborder Caelifera – grasshoppers, pygmy mole crickets and allies Infraorder Acrididea Superfamily Acridoidea – grasshoppers, locusts Superfamily Eumastacoidea – monkey or matchstick grasshoppers and allies Superfamily Locustopsoidea† Superfamily Pneumoroidea – bladder grasshoppers Superfamily Pyrgomorphoidea – gaudy grasshoppers Superfamily Tanaoceroidea – desert long-horned grasshoppers Superfamily Tetrigoidea – ground-hoppers or grouse locusts Superfamily Trigonopterygoidea – leaf grasshoppers Infraorder Tridactylidea Superfamily Dzhajloutshelloidea† Superfamily Regiatoidea† Superfamily Tridactyloidea – pygmy mole crickets and allies Suborder Ensifera – crickets Superfamily Grylloidea – crickets, mole crickets Superfamily Hagloidea – grigs and allies Superfamily Phasmomimoidea† Superfamily Rhaphidophoroidea – camel crickets, cave crickets, cave wetas Superfamily Schizodactyloidea – dune crickets Superfamily Stenopelmatoidea – wetas and allies Superfamily Tettigonioidea – katydids / bush crickets Several species of Orthoptera are considered pests of crops and rangelands or seeking warmth in homes by humans.
The two species of Orthoptera that cause the most damage are locusts. Locust are known for wiping out fields of crops in a day. Locust have the ability to eat up to their own body weight in a single day. Individuals gather in large groups called swarms, these swarms can range up to 80 million individuals that stretch 460 square miles. Grasshoppers can cause major agricultural damage but not to the documented extent as locust have; these insects feed on weeds and grasses, during times of drought and high population density they will feed on crops. They are known pest in soybean fields and will feed on these crops once preferred food sources have become scarce; the Orthoptera include. The list of dietary laws in the book of Leviticus forbids all flying insects that walk, but makes an exception for certain locusts. Strangely, the dragonfly and cranefly are not kosher; the Torah states the only kosher flying insects with four walking legs have knees that extend above their feet so that they hop. Thus nonjumping Orthoptera such as mole crickets are not kosher.
With new research showing promise in locating alternative biofuel sources in the gut of insects, grasshoppers are one species of interest. The insect's ability to break down cellulose and lignin without producing greenhouse gases has aroused scientific interest. Orthoptera portal List of Orthoptera recorded in Britain Orthopterida Female sperm storage Orthoptera Species File Online Orthoptera Image Gallery Australian Plague Locust Commission The Orthopterists' Society AcridAfrica, les acridiens d'Afrique de l'Ouest "Orthoptera". New International Encyclopedia. 1905. Birdwing Grasshoppers in Belize Sound recordings of Orthoptera at BioAcoustica
The froghoppers, or the superfamily Cercopoidea, are a group of hemipteran insects in the suborder Auchenorrhyncha. Adults are capable of jumping many times their height and length, giving the group their common name, but they are best known for their plant-sucking nymphs which encase themselves in foam in springtime. Traditionally, most of this superfamily was considered a single family, the Cercopidae, but this family has been split into three families for many years now: the Aphrophoridae and Clastopteridae. More the family Epipygidae has been removed from the Aphrophoridae; these families are best known for the nymphal stage, which produces a cover of foamed-up plant sap resembling saliva. The final family in the group, the Machaerotidae, are known as the tube spittlebugs because the nymphs live in calcareous tubes, rather than producing foam as in the other families; the foam serves a number of purposes. It hides the nymph from the view of predators and parasites, it insulates against heat and cold, thus providing thermal control and moisture control.
The nymphs pierce plants and suck sap causing little damage, much of the filtered fluids go into the production of the foam, which has an acrid taste, deterring predators. A few species are serious agricultural pests. Adult froghoppers jump from plant to plant; the froghopper can accelerate at 4,000 m/s2 over 2 mm. Spittlebugs can jump 100 times their own length. Many species of froghopper resemble leafhoppers, but can be distinguished by the possession of only a few stout spines on the hind tibiae, where leafhoppers have a series of small spines. Members of the family Machaerotidae resemble treehoppers, due to a large thoracic spine, but the spine in machaerotids is an enlargement of the scutellum, where treehoppers have the pronotum enlarged. Members of the family Clastopteridae have their wings modified to form false heads at the tail end, an antipredator adaptation. Many adult Cercopidae can bleed reflexively from their tarsi, the hemolymph appears to be distasteful. BBC: "Garden insect is jump champion" List of all Cercopoidea species from COOL database by A Soulier-Perkins in the 2008 Catalogue of Life DrMetcalf: a resource on cicadas, planthoppers and treehoppers "Froth-fly".
New International Encyclopedia. 1906
The Plecoptera are an order of insects known as stoneflies. Some 3,500 species are described worldwide, with new species still being discovered. Stoneflies are found worldwide, except Antarctica. Stoneflies are believed to be one of the most primitive groups of Neoptera, with close relatives identified from the Carboniferous and Lower Permian geological periods, while true stoneflies are known from fossils only a bit younger; the modern diversity, however is of Mesozoic origin. Plecoptera are found in both the Southern and Northern Hemispheres, the populations are quite distinct, although the evolutionary evidence suggests species may have crossed the equator on a number of occasions before once again becoming geographically isolated. All species of Plecoptera are intolerant of water pollution, their presence in a stream or still water is an indicator of good or excellent water quality. Stoneflies have a generalized anatomy, with few specialized features compared to other insects, they have simple mouthparts with chewing mandibles, multiple-segmented antennae, large compound eyes, two or three ocelli.
The legs are robust, with each ending in two claws. The abdomen is soft, may include remnants of the nymphal gills in the adult. Both nymphs and adults have paired cerci projecting from the tip of their abdomens; the name "Plecoptera" means "braided-wings", from the Ancient Greek plekein and pteryx. This refers to the complex venation of their two pairs of wings, which are membranous and fold flat over their backs. Stoneflies are not strong fliers, some species are wingless. A few wingless species, such as the Lake Tahoe benthic stonefly or Baikaloperla, are the only known insects with the exception of Halobates, that are aquatic from birth to death; some true water bugs may be aquatic for their entire lives, but can leave the water to travel. The nymphs streams. A few species found in New Zealand and nearby islands have terrestrial nymphs, but these inhabit only moist environments; the nymphs physically resemble wingless adults, but have external gills, which may be present on any part of the body.
Nymphs can acquire oxygen via diffusing through the exoskeleton, or through gills located on behind the head, on the thorax, or around the anus. Due to their nymph's requirement for well oxygenated water, the species is sensitive to water pollution; this makes them important indicators for water quality. Most species are herbivorous as nymphs, feeding on submerged leaves and benthic algae, but many are hunters of other aquatic arthropods; the female can lay up to one thousand eggs. It will drop the eggs in the water, it may hang on a rock or branch. Eggs are covered in a sticky coating which allows them to adhere to rocks without being swept away by swifting moving currents; the eggs take two to three weeks to hatch, but some species undergo diapause, with the eggs remaining dormant throughout a dry season, hatching only when conditions are suitable. The insects remain in the nymphal form for one to four years, depending on species, undergo from 12 to 36 molts before emerging and becoming terrestrial as adults.
Before becoming adults, nymphs will leave the water, attach to a fixed surface and molt one last time. The adults only survive for a few weeks, emerge only during specific times of the year when resources are optimal; some do not feed at all. Adults are not strong fliers and stay near the stream or lake they hatched from. Traditionally, the stoneflies were divided into two suborders, the "Antarctoperlaria" and the Arctoperlaria. However, the former consists of the two most basal superfamilies of stoneflies, which do not seem to be each other's closest relatives. Thus, the "Antarctoperlaria" are not considered a natural group; the Arctoperlaria, have been divided into two infraorders, the Euholognatha and the Systellognatha. This corresponds to the phylogeny with one exception: the Scopuridae must be considered a basal family in the Arctoperlaria, not assignable to any of the infraorders. Alternatively, the Scopuridae were placed in an unranked clade "Holognatha" together with the Euholognatha, but the Scopuridae do not appear closer to the Euholognatha than to the Systellognatha.
In addition, not adopting the clades Antarctoperlaria and Holognatha allows for a systematic layout of the Plecoptera that adequately reproduces phylogeny, while retaining the traditional ranked taxa. Basal lineages Superfamily Eusthenioidea Family Diamphipnoidae Family Eustheniidae Superfamily Leptoperloidea Family Austroperlidae Family GripopterygidaeSuborder Arctoperlaria Basal family Scopuridae Infraorder Euholognatha Family Capniidae – small winter stoneflies Family Leuctridae – rolled-winged stoneflies Family Nemouridae – spring stoneflies Family Notonemouridae Family Taeniopterygidae – winter stoneflies Infraorder Systellognatha Family Chloroperlidae – green stoneflies Family Perlidae – common stoneflies Family Perlodidae Family Peltoperlidae – roachlike stoneflies Family Styloperlidae Family Pteronarcyidae – salmonflies, giant stoneflies Media related to Plecoptera at Wikimedia Commons Data related to Ple
Hymenoptera is a large order of insects, comprising the sawflies, wasps and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Females have a special ovipositor for inserting eggs into hosts or places that are otherwise inaccessible; the ovipositor is modified into a stinger. The young develop through holometabolism —that is, they have a worm-like larval stage and an inactive pupal stage before they mature; the name Hymenoptera refers to the wings of the insects. All references agree; the Ancient Greek ὑμήν for membrane provides a plausible etymology for the term because species in this order have membranous wings. However, a key characteristic of this order is that the hind wings are connected to the fore wings by a series of hooks. Thus, another plausible etymology involves Hymen, the Ancient Greek god of marriage, as these insects have "married wings" in flight; the cladogram of external relationships, based on a 2008 DNA and protein analysis, shows the order as a clade, most related to endopterygote orders including the Diptera and Lepidoptera.
Hymenoptera originated with the oldest fossils belonging to the family Xyelidae. Social hymenopterans appeared during the Cretaceous; the evolution of this group has been intensively studied by Alex Rasnitsyn, Michael S. Engel, others; this clade has been studied by examining the mitochondrial DNA. Although this study was unable to resolve all the ambiguities in this clade, some relationships could be established; the Aculeata and Proctotrupomorpha were monophyletic. The Megalyroidea and Trigonalyoidea are sister clades; the Cynipoidea was recovered as the sister group to Chalcidoidea and Diaprioidea which are each other's closest relations. The cladogram is based on Schulmeister 2003. Hymenopterans range in size from small to large insects, have two pairs of wings, their mouthparts are adapted with well-developed mandibles. Many species have further developed the mouthparts into a lengthy proboscis, with which they can drink liquids, such as nectar, they have large compound eyes, three simple eyes, ocelli.
The forward margin of the hind wing bears a number of hooked bristles, or "hamuli", which lock onto the fore wing, keeping them held together. The smaller species may have only two or three hamuli on each side, but the largest wasps may have a considerable number, keeping the wings gripped together tightly. Hymenopteran wings have few veins compared with many other insects in the smaller species. In the more ancestral hymenopterans, the ovipositor is blade-like, has evolved for slicing plant tissues. In the majority, however, it is modified for piercing, and, in some cases, is several times the length of the body. In some species, the ovipositor has become modified as a stinger, the eggs are laid from the base of the structure, rather than from the tip, used only to inject venom; the sting is used to immobilise prey, but in some wasps and bees may be used in defense. Hymenopteran larvae have a distinct head region, three thoracic segments, nine or 10 abdominal segments. In the suborder Symphyta, the larvae resemble caterpillars in appearance, like them feed on leaves.
They have large chewing mandibles, three pairs of thoracic limbs, and, in most cases, six or eight abdominal prolegs. Unlike caterpillars, the prolegs have no grasping spines, the antennae are reduced to mere stubs. Symphytan larvae that are wood borers or stem borers have no abdominal legs and the thoracic legs are smaller than those of non-borers. With rare exceptions larvae of the suborder Apocrita have no legs and are maggotlike in form, are adapted to life in a protected environment; this may be the body of a host organism, or a cell in a nest, where the adults will care for the larva. In parasitic forms, the head is greatly reduced and withdrawn into the prothorax. Sense organs appear to be poorly developed, with no ocelli small or absent antennae, toothlike, sicklelike, or spinelike mandibles, they are unable to defecate until they reach adulthood due to having an incomplete digestive tract to avoid contaminating their environment. The larvae of stinging forms have 10 pairs of spiracles, or breathing pores, whereas parasitic forms have nine pairs present.
Among most or all hymenopterans, sex is determined by the number of chromosomes an individual possesses. Fertilized eggs get two sets of chromosomes and develop into diploid females, while unfertilized eggs only contain one set and develop into haploid males; the act of fertilization is under the voluntary control of the egg-laying female, giving her control of the sex of her offspring. This phenomenon is called haplodiploidy. However, the actual genetic mechanisms of haplodiploid sex determination may be more complex than simple chromosome number. In many Hymenoptera, sex is determined by a single gene locus with many alleles. In these species, haploids are male and diploids heterozygous at the sex locus are female, but a diploid will be homozygous at the sex locus and develop as a male, instead; this is likely to occur in an individual whose parents were siblings or other close relatives. Diploid males are known to be produced by inbreeding in many ant and wasp species