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29-451: The Agelenidae are a large family of spiders in the suborder Araneomorphae . Well-known examples include the common "grass spiders" of the genus Agelenopsis . Nearly all Agelenidae are harmless to humans, but the bite of the hobo spider ( Eratigena agrestis ) may be medically significant, and some evidence suggests it might cause necrotic lesions, but the matter remains subject to debate. The most widely accepted common name for members of

58-468: A courting male, the threatening struggles of dangerous invaders, or the weaker struggles of potential meals. They attack promising prey by rushing out at high speed and dealing a paralysing venomous bite. The agatoxin in their venom has been studied extensively in Agelenopsis aperta . Once the prey has been disabled, the spider generally drags it back into the retreat and begins to feed. This method of attack

87-438: A form of trophallaxis. The recipient wolves often lick or sniff the donor wolf's muzzle to activate regurgitation and receive nutrients. Vampire bats share blood with kin by regurgitation as a means of increasing their fitness through kin selection. Birds regurgitate food and directly transfer it into the mouths of their offspring as a part of parental care, such as the " crop milk " that is transferred by mother ring doves into

116-446: A parasitic strategy in some species to obtain food from their host. Trophallaxis can also result in the spreading of chemicals, such as pheromones , throughout a colony, which is significant in social colony functioning. Species have evolved anatomy to allow them to participate in trophallaxis, such as the proventriculus in the crops of Formica fusca ants. This structure acts as a valve to enhance food storage capacity. Likewise,

145-538: A putative cause of a significant frequency of necrotic arachnidism ; this is the hobo spider , Eratigena agrestis . This perception arose when the species was accidentally introduced to the United States in the mid-20th century and propagated rapidly in several regions. It is a fairly large, rapidly moving spider, so accordingly alarms many people. A few cases of bites have been reported in Southern California by

174-614: A sort of "communal stomach" for the colony. This is also true for certain species of Lasioglossum , such as the sweat bee Lasioglossum hemichalceum . L. hemichalceum will often exchange food with other members regardless of whether they are nestmates or not. This is because cooperation among non-relatives offers more benefit than cost to the group. Many wasps, like Protopolybia exigua and Belonogaster petiolata , exhibit foraging behavior where adults perform trophallaxis with adults and between adults and larvae. P. exigua carry nectar, wood pulp and macerated prey in its crop from

203-518: Is an obligate parasite species that invades the nests of host species and obtains food by constraining the host with their legs and forcing trophallaxis. Vertebrates such as some bird species, gray wolves , and vampire bats also feed their young through regurgitation of food as a form of trophallaxis. Food sharing in vertebrates is a form of reciprocity demonstrated by many social vertebrates. Wild wolves transport food in their stomach to pups and/or breeding females and share it by regurgitation, as

232-482: Is consistent with the high speeds at which the Agelenidae run. Other sheet-web hunters such as some Pisauridae also are very fast runners. Like any fast-running spider, the Agelenidae possess good vision, and are generally photosensitive (i.e. react to changes in the light), so they can successfully retreat upon perceiving a larger threat's shadow approaching. Some are also sensitive to wind blows, and can retreat before

261-454: Is probably A. consociata . Social behaviour in these spiders comprises communal web-building, cooperative prey capture, and communal rearing of young. No trophallaxis occurs, though, nor does any true eusociality such as occurs in the social Hymenoptera (ants, bees, and wasps); for example, the spiders have no castes such as sterile workers or soldiers, and all females are reproductive. Only one species of agelenid has become prominent as

290-568: The Labidognatha or " true spiders " ) are an infraorder of spiders . They are distinguishable by chelicerae (fangs) that point diagonally forward and cross in a pinching action, in contrast to the Mygalomorphae (tarantulas and their close kin), where they point straight down. Araneomorphs comprise the vast majority (about 93% ) of living spiders. Most spider species are Araneomorphae, which have fangs that face towards each other, increasing

319-648: The Neocribellatae . The Neocribellatae were in turn divided into the Austrochiloidea, and the two series Haplogynae and Entelogynae, each containing several superfamilies . Molecular phylogenetic studies have shown that the haplogynes in particular are not a monophyletic group. A 2020 study suggested the relationships among the major groups were as shown in the following cladogram. Hypochilidae Filistatidae Synspermiata Leptonetidae Austrochiloidea Palpimanoidea Entelegynae The blue bar to

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348-462: The giant house spider held the Guinness Book of World Records title for top spider speed until 1987. A recent literature review found peer-reviewed accounts of several agelenid species achieving speeds in this range, though some other taxa have achieved higher speeds. Agelenids build a flat sheet of nonsticky web with a funnel-shaped retreat to one side or occasionally in the middle, depending on

377-438: The colony. In some species of ants, it may play a role in spreading the colony odour that identifies members. Honey bee foragers use trophallaxis in associative learning to form long-term olfactory memories, in order to teach nest mates foraging behavior and where to search for food. In addition, Vespula austriaca wasps also engage in trophallaxis as a form of parasitism with its host to obtain nutrients. V. austriaca

406-485: The colony. In termites, proctodeal trophallaxis is crucial for replacing the gut endosymbionts that are lost after every molt. Gut symbionts are also transferred by anal trophallaxis in wood-eating termites and cockroaches. Transfer of gut symbionts in these species is essential to digest wood as their food source. Carpenter ants transfer immunity through trophallaxis by the direct transfer of antimicrobial substances, increasing disease resistance and social immunity of

435-521: The corners of rooms, and between windows and screens; the crab spiders that lurk on the surfaces of flowers in gardens; the jumping spiders that are visible hunting on surfaces; the wolf spiders that carpet hunting sites in sunny spots; and the large huntsman spiders . In older schemes, the Araneomorphae were divided into two lineages, the Hypochilae (containing only the family Hypochilidae ), and

464-511: The desert grass spider, Agelenopsis aperta, that resulted in symptoms, but determining whether these cases were confused with similar-looking spiders is difficult. As of January 2023, the World Spider Catalog accepts these genera: A number of fossil species are known from Eocene aged Baltic amber , but their exact relationship with extant members of the clade is unclear. Araneomorphae The Araneomorphae (also called

493-442: The family is funnel weaver . The body length of the smallest Agelenidae spiders are about 4 mm (0.16 in), excluding the legs, while the larger species grow to 20 mm (0.79 in) long. Some exceptionally large species, such as Eratigena atrica , may reach 5 to 10 cm (2.0 to 3.9 in) in total leg span. Agelenids have eight eyes in two horizontal rows of four. Their cephalothoraces narrow somewhat towards

522-410: The females often live many years. Almost all of the familiar spiders are included in the Araneomorphae group, one major exception being the tarantulas . There are a few other Mygalomorphae species that live around homes or gardens, but they typically are relatively small and not easily noticed. The Araneomorphae, to the contrary, include the weavers of spiral webs ; the cobweb spiders that live in

551-494: The field to the nest for transfer; for larvae survival they carry amounts of prey proportional to the amount of larvae in the nest. Voluntary trophallaxis in Xylocopa pubescens bees has led to the nest guarding behavior that the species is known for. This bee species allows one adult to forage and bring nectar back for the rest of the nest population as a way to continually defend the nest while obtaining nutrients for all members of

580-505: The formation of social bonds. Trophallaxis serves as a means of communication , at least in bees , like M. genalis , and ants. Trophallaxis in M. genalis is part of a social exchange system, where dominant bees are usually the recipients of food. It increases longevity of bees that have less access to food and decreases aggression between nest mates. In the red fire ant, colony members store food in their crops and regularly exchange this food with other colony members and larvae to form

609-474: The front where the eyes are. Their abdomens are more or less oval, usually patterned with two rows of lines and spots. Some species have longitudinal lines on the dorsal surface of the cephalothorax, whereas other species do not; for example, the hobo spider does not, which assists in informally distinguishing it from similar-looking species. Most of the Agelenidae are very fast runners, especially on their webs. With speeds clocked at 1.73 ft/s (0.53 m/s),

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638-458: The honey bee Apis mellifera is able to protrude their proboscis and sip nectar from the open mandibles of the donor bee. Certain mechanisms have also evolved to initiate food sharing, such as the sensory exploitation strategy that has evolved in the common cuckoo brood parasites. These birds have evolved brightly coloured gapes that stimulate the host to transfer food. Trophallaxis is a form of social feeding in many insects that contributes to

667-449: The like. They await the arrival of prey such as grasshoppers that fall onto the horizontal web. Although the web is not sticky, it is full of entangling filaments that the spider continually lays down when passing over. The filaments catch in the least projections on a prey insect's body or limbs. The web also is springy, and whether perching on the sheet or awaiting prey in its retreat, the spider reacts immediately to vibrations, whether from

696-399: The mouths of their young. The cuckoo brood parasite is another bird species that engages in trophallaxis. The cuckoo bird uses mimicry, such as mimicking the eggshell colors and patterns of the host's eggs, to place their young in the nest of host species where they will be fed and reared at no expense to the cuckoo mother. The cuckoo young can often mimic the begging call of an entire nest of

725-403: The orientations that they can employ during prey-capture. They have fewer book lungs (when present) - usually one pair - and the females typically live one year. The Mygalomorphae have fangs that face towards the ground, and which are parallel to the long axis of the spider's body, thus they have only one orientation they can employ during prey capture. They have two pairs of book lungs, and

754-816: The prey even spots them. Males are less successful ambushers than females, so prefer to roam around and wander to new areas, rather than stay in one single web. In September, males of outdoors species (such as Agelenopsis and Agelena ) can seek refuge within houses, usually nesting on or underneath outer windowsills, or also around the porch door. These spiders often are neither pest controllers nor pests themselves; they are very selective in their prey, and do not consume large quantities; also, they are immune to intimidation and come back to their webs even after being disturbed, unless they are completely destroyed. The type genus, Agelena , includes some parasocial spiders that live in complex communal webs in Africa. The best known of these

783-532: The right shows the former Haplogynae in the sense of Coddington (2005). Trophallaxis Tropho- (prefix or suffix) is derived from the Greek trophé, meaning 'nourishment'. The Greek 'allaxis' means 'exchange'. The word was introduced by the entomologist William Morton Wheeler in 1918. Trophallaxis was used in the past to support theories on the origin of sociality in insects. The Swiss psychologist and entomologist Auguste Forel also believed that food sharing

812-472: The situation and species. Accordingly, "funnel weaver" is the most widely accepted common name for members of the family, but they should not be confused with the so-called "funnel-web tarantulas" or "funnel-web spiders" of mygalomorph families. The typical hunting mode for most sheet-building Agelenidae is similar to that of most other families of spiders that build sheet webs in the open, typically on grass or in scrubland as opposed to under bark, rocks, and

841-609: Was key to ant society and he used an illustration of it as the frontispiece for his book The Social World of the Ants Compared with that of Man . Proctodeal trophallaxis allowed termites to transfer cellulolytic flagellates that made the digestion of wood possible and efficient. Besides sociality, trophallaxis has evolved within many species as a method of nourishment for adults and/or juveniles, kin survival, transfer of symbionts, transfer of immunity, colony recognition and foraging communication. Trophallaxis has even evolved as

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