The ovipositor is a tube-like organ used by some animals , especially insects , for the laying of eggs . In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typically its form is adapted to functions such as preparing a place for the egg, transmitting the egg, and then placing it properly. For most insects, the organ is used merely to attach the egg to some surface, but for many parasitic species (primarily in wasps and other Hymenoptera ), it is a piercing organ as well.
43-589: Blattella is a genus of cosmopolitan and wild cockroaches in the family Ectobiidae . The Catalogue of Life lists the following: Cockroach Anaplectidae Blaberidae Blattidae Corydiidae Cryptocercidae Ectobiidae Lamproblattidae Nocticolidae Tryonicidae Cockroaches (or roaches ) are insects belonging to the order Blattodea (Blattaria). About 30 cockroach species out of 4,600 are associated with human habitats . Some species are well-known pests . Modern cockroaches are an ancient group that first appeared during
86-443: A burrow into the earth to receive the eggs. Cicadas pierce the wood of twigs with their ovipositors to insert the eggs. Sawflies slit the tissues of plants by means of the ovipositor and so do some species of long-horned grasshoppers . In the ichneumon wasp genus Megarhyssa , the females have a slender ovipositor (terebra) several inches long that is used to drill into the wood of tree trunks . These wasps are parasitic in
129-409: A common shelter, overlapping generations, non-closure of groups, equal reproductive potential of group members, an absence of task specialization, high levels of social dependence, central place foraging, social information transfer, kin recognition , and a meta-population structure. There is evidence that a few species of group-living roaches in the genera Melyroidea and Aclavoidea may exhibit
172-462: A functional ovipositor. Fig wasp ovipositors have specialized serrated teeth to penetrate fruits, but gall wasps have either uniform teeth or no teeth on their ovipositors, meaning the morphology of the organ is related to the life history. Members of the Dipteran (fly) families Tephritidae and Pyrgotidae have well-developed ovipositors that are partly retracted when not in use, with
215-469: A group. In one study, isolated cockroaches were less likely to leave their shelters and explore, spent less time eating, interacted less with conspecifics when exposed to them, and, among males, took longer to recognize receptive females. Because these changes occurred in many contexts, the authors suggested them as constituting a behavioral syndrome . These effects might have been due either to reduced metabolic and developmental rates in isolated individuals or
258-403: A pair of spiracles for respiration. In addition to the spiracles, the final segment consists of a pair of cerci , a pair of anal styles, the anus and the external genitalia. Males have an aedeagus through which they secrete sperm during copulation, while females have spermatheca for storing sperm and an ovipositor through which the oothecae are laid. Cockroaches are abundant throughout
301-422: A reproductive division of labor, which, if confirmed, would make these the only genuinely eusocial lineage known among roaches, in contrast to the subsocial members of the genus Cryptocercus . Some species make a buzzing noise while other cockroaches make a chirping noise. Gromphadorhina species and Archiblatta hoeveni produce sound through the modified spiracles on the fourth abdominal segment. In
344-413: A separate order Isoptera to cockroaches. However, recent genetic evidence strongly suggests that they evolved directly from 'true' cockroaches, and many authors now place them as an " epifamily " of Blattodea. This evidence supported a hypothesis suggested in 1934 that termites are closely related to the wood-eating cockroaches (genus Cryptocercus ). This hypothesis was originally based on similarity of
387-595: A simple set of individual interactions. Daily rhythms may also be regulated by a complex set of hormonal controls of which only a small subset have been understood. In 2005, the role of one of these proteins, pigment dispersing factor (PDF), was isolated and found to be a key mediator in the circadian rhythms of the cockroach. Pest species adapt readily to a variety of environments, but prefer warm conditions found within buildings. Many tropical species prefer even warmer environments. Cockroaches are mainly nocturnal and run away when exposed to light. An exception to this
430-549: A system of tubes called tracheae which are attached to openings called spiracles on all body segments. When the carbon dioxide level in the insect rises high enough, valves on the spiracles open and carbon dioxide diffuses out and oxygen diffuses in. The tracheal system branches repeatedly, the finest tracheoles bringing air directly to each cell , allowing gaseous exchange to take place. While cockroaches do not have lungs as do vertebrates , and can continue to respire if their heads are removed, in some very large species,
473-528: Is also sometimes used to refer to extinct cockroach relatives. The earliest cockroach-like fossils ("blattopterans" or " roachoids ") are from the Carboniferous period 320 million years ago. Fossil roachoids are considered the common ancestor of both mantises and modern cockroaches, and are distinguished from the latter by the presence of a long external ovipositor . As the body, hind wings and mouthparts are not preserved in fossils frequently,
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#1732772839061516-425: Is and how many other cockroaches there are. A study used specially scented roach-sized robots that seem real to the roaches to demonstrate that once there are enough insects in a place to form a critical mass , the roaches accepted the collective decision on where to hide, even if this was an unusually lit place. When reared in isolation, German cockroaches show behavior that is different from behavior when reared in
559-735: Is the Asian cockroach , which flies mostly at night but is attracted to brightly lit surfaces and pale colors. Gregarious cockroaches display collective decision-making when choosing food sources. When a sufficient number of individuals (a "quorum") exploits a food source, this signals to newcomer cockroaches that they should stay there longer rather than leave for elsewhere. Other mathematical models have been developed to explain aggregation dynamics and conspecific recognition. Cooperation and competition are balanced in cockroach group decision-making behavior. Cockroaches appear to use just two pieces of information to decide where to go, namely how dark it
602-471: Is the Central American giant cockroach Blaberus giganteus . The longest cockroach species is Megaloblatta longipennis , which can reach 97 mm ( 3 + 7 ⁄ 8 in) in length and 45 mm ( 1 + 3 ⁄ 4 in) across. A Central and South American species, Megaloblatta blaberoides , has the largest wingspan of up to 185 mm ( 7 + 1 ⁄ 4 in). At
645-410: Is time to release the fry into a suitable situation in the open water. The marbled newt , or Triturus marmoratus, females participate in parental investment by ovipositing their eggs. They carefully wrap them in aquatic leaves as a form of protection, scattering them throughout a pond to avoid predation. Females are not able to breathe during the oviposition process; therefore, the benefit to wrapping
688-491: The Late Jurassic , with their ancestors, known as " roachoids ", likely originating during the Carboniferous period around 320 million years ago. Those early ancestors, however, lacked the internal ovipositors of modern roaches. Cockroaches are somewhat generalized insects lacking special adaptations (such as the sucking mouthparts of aphids and other true bugs ); they have chewing mouthparts and are probably among
731-441: The cuticle may enable cockroaches to distinguish between different populations of cockroach by odor. The behaviors involved have been studied in only a few species, but German cockroaches leave fecal trails with an odor gradient. Other cockroaches follow such trails to discover sources of food and water, and where other cockroaches are hiding. Thus, cockroaches have emergent behavior , in which group or swarm behavior emerges from
774-528: The larval stage on the larvae of horntail wasps, hence the egg must be deposited directly into the host's body as it is feeding. The ovipositors of Megarhyssa are among the longest egg-laying organs (relative to body size) known. The stingers of the Aculeata (wasps, hornets, bees, and ants) are ovipositors, highly modified and with associated venom glands . They are used to paralyze prey, or as defensive weapons. The penetrating sting plus venom allows
817-500: The body musculature may contract rhythmically to forcibly move air in and out of the spiracles; this may be considered a form of breathing. Ovipositor Some ovipositors only retract partly when not in use, and the basal part that sticks out is known as the scape , or more specifically oviscape , the word scape deriving from the Latin word scāpus , meaning "stalk" or "shaft". Grasshoppers use their ovipositors to force
860-519: The continent. 450 species are found in Australia . Only about four widespread species are commonly regarded as pests. Cockroaches occupy a wide range of habitats. Many live in leaf litter , among the stems of matted vegetation, in rotting wood, in holes in stumps, in cavities under bark, under log piles and among debris. Some live in arid regions and have developed mechanisms to survive without access to water sources. Others are aquatic, living near
903-618: The day in crevices, among dead leaves, in bird and insect nests or among epiphytes , emerging at night to feed. Cockroaches are social insects; a large number of species are either gregarious or inclined to aggregate, and a slightly smaller number exhibit parental care. It used to be thought that cockroaches aggregated because they were reacting to environmental cues, but it is now believed that pheromones are involved in these behaviors. Some species secrete these in their feces with gut microbial symbionts being involved, while others use glands located on their mandibles . Pheromones produced by
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#1732772839061946-648: The fact that the isolated individuals had not had a training period to learn about what others were like via their antennae. Individual American cockroaches appear to have consistently different "personalities" regarding how they seek shelter. In addition, group personality is not simply the sum of individual choices, but reflects conformity and collective decision-making. The gregarious German and American cockroaches have elaborate social structure , chemical signaling, and "social herd" characteristics. Lihoreau and his fellow researchers stated: The social biology of domiciliary cockroaches ... can be characterized by
989-522: The former species, several different hisses are produced, including disturbance sounds, produced by adults and larger nymphs; and aggressive, courtship and copulatory sounds produced by adult males. Henschoutedenia epilamproides has a stridulatory organ between its thorax and abdomen, but the purpose of the sound produced is unclear. Several Australian species practice acoustic and vibration behaviour as an aspect of courtship. They have been observed producing hisses and whistles from air forced through
1032-423: The front legs are the shortest and the hind legs the longest, providing the main propulsive power when the insect runs. The spines on the legs were earlier considered to be sensory, but observations of the insect's gait on sand and wire meshes have demonstrated that they help in locomotion on difficult terrain. The structures have been used as inspiration for robotic legs. The abdomen has ten segments, each having
1075-424: The gregarious German cockroach , have an elaborate social structure involving common shelter, social dependence, information transfer and kin recognition. Cockroaches have appeared in human culture since classical antiquity . They are popularly depicted as large, dirty pests, although the majority of species are small and inoffensive and live in a wide range of habitats around the world. Cockroaches are members of
1118-578: The insect is to utilize cellulose; however, some species secrete cellulase in their saliva , and the wood-eating cockroach, Panesthia cribrata , is able to survive indefinitely on a diet of crystallized cellulose while being free of microorganisms. The similarity of these symbionts in the genus Cryptocercus to those in termites are such that these cockroaches have been suggested to be more closely related to termites than to other cockroaches, and current research strongly supports this hypothesis about their relationships. All species studied so far carry
1161-482: The light", which in classical Latin was applied not only to cockroaches, but also to mantids . Historically, the name Blattaria was used largely interchangeably with the name Blattodea, but whilst Blattaria was used to refer to 'true' cockroaches exclusively, the Blattodea also includes the termites. The current catalogue of world cockroach species uses the name Blattodea for the group. Another name, Blattoptera ,
1204-625: The most primitive of living Neopteran insects. They are common and hardy insects capable of tolerating a wide range of climates , from Arctic cold to tropical heat. Tropical cockroaches are often much larger than temperate species. Modern cockroaches are not considered to be a monophyletic group, as it has been found based on genetics that termites are deeply nested within the group, with some groups of cockroaches more closely related to termites than they are to other cockroaches, thus rendering Blattaria paraphyletic . Both cockroaches and termites are included into Blattodea. Some species, such as
1247-575: The obligate mutualistic endosymbiont bacterium Blattabacterium , with the exception of Nocticola , an Australian cave-dwelling genus without eyes, pigment or wings, which recent genetic studies indicate is a very primitive cockroach. It had previously been thought that all five families of cockroach were descended from a common ancestor that was infected with B. cuenoti . It may be that N. australiensis subsequently lost its symbionts, or alternatively this hypothesis will need to be re-examined. Like other insects, cockroaches breathe through
1290-693: The order Blattodea. Other scientists have taken a more conservative approach, proposing to retain the termites as the Termitoidae , an epifamily within the order. Such a measure preserves the classification of termites at family level and below. Most species of cockroach are about the size of a thumbnail , but several species are notably larger. The world's heaviest cockroach is the Australian giant burrowing cockroach Macropanesthia rhinoceros , which can reach 8 centimetres (3 in) in length and weigh up to 35 grams (1.2 oz). Comparable in size
1333-523: The other end of the size scale, Attaphila cockroaches that live with leaf-cutter ants include some of the world's smallest species, growing to about 3.5 mm in length. Cockroaches are generalized insects with few special adaptations, and may be among the most primitive living Neopteran insects. They have a relatively small head and a broad, flattened body, and most species are reddish-brown to dark brown. They have large compound eyes , two ocelli , and long, flexible antennae . The mouthparts are on
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1376-553: The part that sticks out being the oviscape. Oestridae , another family within Diptera, often have short hairy ovipositors, the species Cuterebra fontinella has one of the shortest within the family. Ovipositors exist not only in winged insects , but also in Apterygota , where the ovipositor has an additional function in gathering the spermatophore during mating. Little is known about the egg-laying habits of these insects in
1419-494: The relationship of these roachoids and modern cockroaches remains disputed. The earliest definitive fossils of modern crown group cockroaches, specifically Corydiidae , are known from the Late Jurassic rocks of Russia . The evolutionary relationships of the Blattodea (cockroaches and termites) shown in the cladogram are based on Inward, Beccaloni and Eggleton (2007). The cockroach families Anaplectidae , Lamproblattidae , and Tryonicidae are not shown but are placed within
1462-424: The second and third thoracic segments. The tegmina , or first pair of wings, are tough and protective; these lay as a shield on top of the membranous hind wings , which are used in flight. All four wings have branching longitudinal veins, as well as multiple cross-veins . The three pairs of legs are sturdy, with large coxae and five claws each. They are attached to each of the three thoracic segments. Of these,
1505-836: The spiracles. Furthermore, in the presence of a potential mate, some cockroaches tap the substrate in a rhythmic, repetitive manner. Acoustic signals may be of greater prevalence amongst perching species, particularly those that live on low vegetation in Australia's tropics. Cockroaches are generally omnivorous ; the American cockroach ( Periplaneta americana ), for example, feeds on a great variety of foodstuffs including bread, fruit, leather, starch in book bindings, paper, glue, skin flakes, hair, dead insects and soiled clothing. Many species of cockroach harbor in their gut symbiotic protozoans and bacteria which are able to digest cellulose . In many species, these symbionts may be essential if
1548-639: The superfamily Blattoidea. The cockroach families Corydiidae and Ectobiidae were previously known as the Polyphagidae and Blattellidae. Termitidae Rhinotermitidae Kalotermitidae Archotermopsidae Hodotermitidae Mastotermitidae Cryptocercidae (brown-hooded cockroaches) Blattidae (Oriental, American and other cockroaches) Blaberidae (giant cockroaches) Ectobiidae (part) Ectobiidae (part) Corydiidae (sand cockroaches, etc) Nocticolidae (cave cockroaches, etc) Mantodea (mantises) Termites were previously regarded as
1591-493: The superorder Dictyoptera , which includes the termites and mantids , a group of insects once thought to be separate from cockroaches. Currently, 4,600 species and over 460 genera are described worldwide. The name " cockroach " comes from the Spanish word for cockroach, cucaracha , transformed by 1620s English folk etymology into "cock" and "roach". The scientific name derives from the Latin blatta , "an insect that shuns
1634-411: The surface of water bodies, including bromeliad phytotelmata , and diving to forage for food. Most of these respire by piercing the water surface with the tip of the abdomen which acts as a snorkel , but some carry a bubble of air under their thoracic shield when they submerge. Others live in the forest canopy where they may be one of the main types of invertebrate present. Here they may hide during
1677-458: The symbiotic gut flagellates in termites regarded as living fossils and wood-eating cockroaches. Additional evidence emerged when F. A. McKittrick (1965) noted similar morphological characteristics between some termites and cockroach nymphs. The similarities among these cockroaches and termites have led some scientists to reclassify termites as a single family, the Termitidae , within
1720-450: The underside of the head and include generalized chewing mandibles , salivary glands and various touch and taste receptors. The body is divided into a thorax of three segments and a ten-segmented abdomen. The external surface has a tough exoskeleton which contains calcium carbonate ; this protects the inner organs and provides attachment to muscles. This external exoskeleton is coated with wax to repel water. The wings are attached to
1763-512: The wasp to lay eggs with less risk of injury from the host. In some cases, the injection also introduces virus particles that suppress the host's immune system and prevent it from destroying the eggs. However, in virtually all stinging Hymenoptera , the ovipositor is no longer used for egg-laying. An exception is the family Chrysididae , members of the Hymenoptera, in which species such as Chrysis ignita have reduced stinging apparatus and
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1806-401: The wild. Female bitterlings in the genus Rhodeus have an ovipositor in the form of a tubular extension of the genital orifice. During breeding season, they use it when depositing eggs in the mantle cavity of freshwater mussels , where their eggs develop in reasonable security. Seahorses have an ovipositor for introducing eggs into the brood pouch of the male, who carries them until it
1849-462: The world and live in a wide range of environments, especially in the tropics and subtropics . Cockroaches can withstand extremely low temperatures, allowing them to live in the Arctic . Some species are capable of surviving temperatures of −122 °C (−188 °F) by manufacturing an antifreeze made out of glycerol . In North America , 50 species separated into five families are found throughout
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