Trichonephila plumipes | |
---|---|
![]() | |
Female eating a ladybird, with male in attendance | |
Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Subphylum: | Chelicerata |
Class: | Arachnida |
Order: | Araneae |
Infraorder: | Araneomorphae |
Family: | Nephilidae |
Genus: | Trichonephila |
Species: | T. plumipes |
Binomial name | |
Trichonephila plumipes | |
Synonyms | |
|
Trichonephila plumipes, the Pacific golden orb weaver, [1] is a species of spider found in Australia, Indonesia and some Pacific Islands, which exhibits extreme sexual dimorphism through its sexual cannibalism behavior. It is sometimes called the tiger spider due to its markings which look similar to a tiger. This species was formerly called Nephila plumipes. As with other spiders from the genus Nephila , these spiders have a distinct golden web.
The Trichonephila plumipes benefits from highly urbanized places due to more available food, warmer temperatures, and fewer predators. This species is commonly found in urban and natural landscapes. [3]
T. plumipes is most commonly found in Australia, Indonesia, New Guinea, Solomon Islands, Vanuatu, New Ireland and New Caledonia. [4]
T. plumipes resembles most of its congeners in the general body form. Females of the T. plumipes species resemble those of T. clavipes in that they possess a collection of stiff hair on their legs. However, the hairs of T. plumipes are more closely set together than those of T. clavipes. In a T. plumipes female, the cephalothorax is black, covered with silver-colored hairs. The abdomen is olive-brown with yellow and white spots and stripes. On several pairs of its legs, there are brushes of stiff black hairs. The body of the males are dark brown. The legs are dark brown as well, with a few scattering black hairs, without the brushes that are present in the female. [5]
T. plumipes is a large spider. Females can achieve a body length of 34mm, while males are smaller and rarely exceed 5mm in body length. Males can be less than one-tenth the size of females. [6] Some males may weigh less than 1% of the body weight of mature females. [7] The extreme sexual size dimorphism of T. plumipes is the result of selection due to the females predisposition to engage in pre-copulation sexual cannibalism. The smaller-sized males may better evade pre-copulation sexual cannibalism because of the female T. plumipes inability to detect these smaller males and thus this smaller size is selected for. [6]
There is a large variance value in male body size, indicating that although a smaller body may evade pre-copulation sexual cannibalism, there still exists benefits to larger body sizes. The variance in male body size of T. plumipes is 44.4, twice that of other male spiders of similarly sized species. This is because smaller males are less likely to be detected and cannibalized by females before copulation, but larger males can exclude small males from the central hub of the web where mating takes place. Smaller males pay the cost of getting fewer mating opportunities and being replaced by larger males. The conflicting effects of pre-copulation sexual cannibalism and male-male competition results in the large variation in male size. [6]
Twelve Trichonephila species have had taxonomic changes. These twelve Trichonephila species were all formerly in classical Nephila, but phylogenetic results have established the classical Nephila as diphyletic. Because classical Nephila is diphyletic, the new Nephila genus now only includes the Australasian N. pilipes and the African N. constricta. The remaining twelve species, including T. plumipes, were assigned to the circumtropical Trichonephila. Thus, Nephila plumipes is the synonym of Trichonephila plumipes. [8] The divergence between N. pilipes, theN. constricta clade, and the other new Trichonephila species is dated 11.9 Mya. The subsequent diversification for the separation of T. plumipes and other Asian/Australian Trichonephila species was dated 10.9 million years ago. [9]
T. plumipes reaches high densities in Sydney, Australia. T. plumipes has previously been shown to have positive response to urban landscapes. This urban-exploiting species benefits from multiple factors in cities. A study shows that T. plumipes were found to persist longer at sites with more concrete surfaces and less vegetation cover. Increases in concrete surfaces and decreases in vegetation cover can drive the urban heat island effect, which is a result of urban areas being warmer than rural areas due to human activity. In these warmer conditions, T. plumipes’ orb weaver season is extended. Normally, T. plumipes juveniles overwinter in egg sacs, hatch in the spring, and mature in the summer. However, in warmer winters, females can produce eggs faster, and the egg sacs can hatch within the same season, instead of remaining dormant in the winter. In this way, T. plumipes can complete two life cycles in the same season. This results in higher fitness and increased success for T. plumipes in urban areas. Another factor of the T. plumipes success in urban regions is the abundance of prey. There are more large prey in urban microhabitats due to urban warming, artificial night lightings, and the loss of predators. Food resources play a big role in the increased survival of T. plumipes in urban areas. [3]
T. plumipes spins a relatively permanent web. They capture most of their prey during the day. This diurnal preying schedule is due to the fact that T. plumipes captures mostly Hymenoptera , which are more abundant during the day than the night. [10] Both sexes build webs for prey capture. The size of the web and the web location affects resource acquisition. [11]
The silks produced by T. plumipes could be classified as both bee visible and bee invisible. The bee visible silks appear yellow or golden to the human eye, while the bee invisible silks are white/silver to the human eye. The colors of the silk are not related to spider's protein intake. The yellow coloration of T. plumipes silk is not due to carotinoid intake from the food. The silk colors are correlated with silk thermal properties rather than silk protein structure. The conspicuous yellow coloration of T. plumipes silk is selectively attractive to certain prey species, but it might also attract the predators. The yellow and white coloration of T. plumipes silk might be the result of trade-offs between prey and predator attraction. The balance of this trade-off determines if T. plumipes silk is visible to bees or not. [12]
T. plumipes incorporate prey they previously captured into their webs. They apply a long-term storage mechanism. They incorporate a densely packed storage band of previously captured uneaten prey into their web that is attached to the barrier web near the hub. They can maintain their body mass when there is low level of prey capture by eating the stored items. T. plumipes incorporate only animal material in their storage, but some other species in the Trichonephila genus utilize plant material in the storage serving some unidentified non-food-storing functions. A disadvantage of hoarding behavior is that the prey items stored may be lost to kleptoparasites or through web damage. Spiders in the genus Trichonephila are often host to kleptoparasitic spiders. Food storage in the web can attract more kleptoparasites. However, a study showed that the abundance of kleptoparasites does not affect T. plumipes weight gain. Kleptoparasites feed on prey items ignored by the host spider, which does not affect the nutrients intake of the host spider. [13]
Upon maturity, T. plumipes males leave their natal webs to search for females' webs. Females' webs are used for mate attraction and are also used as the mating arena. Females produce web-based, long-distance cuticular pheromones for males to locate them. [11] Multiple males can settle on a single female's web and wait for an opportunity to mate. In T. plumipes, females are polygynous, while males are monogynous due to a high chance of injury and sexual cannibalism by their first mate. Male survival during mate searching is extremely low at 36%. The high mortality rate is due to males' increased search time. Factors such as encountering predators and depleting energy reserves decrease male survival during mate searching. T. plumipes males have a long mate search time. Since they have only one single opportunity to mate, they are choosy. A male's mate choice is based on their own condition and weight. Males that choose virgin females are heavier than those that choose mated females. Thus, males are choosy about female phenotype or mating status, taking their own factors into consideration. As a result, males travel further than necessary, roughly eight meters, to find preferred mates. [14]
T. plumipes females cannibalize males both before and during copulation. In T. plumipes, although cannibalized males copulate for longer than the males that escape, they do not transfer more sperm. But males who mate with mated females transfer more sperm than the ones who mate with virgin females. Males benefit from sexual cannibalism because of higher fertilization success. Males that survive copulation with mated females do not sire more than 30% of the clutch, but if he is cannibalized, this value is doubled. Females benefit from sexual cannibalism by gaining more nutrients. Virgin females that are small in size and in poor condition are more likely to cannibalize males. [15] For pre-copulation sexual cannibalism, female T. plumipes are less likely to capture small males over large males. This might occur because females cannot detect them. But after copulation starts, females always want to cannibalize, regardless of the males' size. [6]
T. plumipes settles both solitarily and aggregates with neighbors. Although the females have their own web, they have a tendency to settle nearby one another and create aggregations. Females can switch between solitary and aggregative settlement as the breeding season progresses. [11] The large aggregations have as many as ten webs that either share structural threads or are found within 20 cm of another web. [7] The female aggregations consist of females of different ages and mating statuses, ranging from juveniles to mated adults. Female settlement decisions are determined by various factors including the presence of predators, kleptoparasites, availability of prey, benefits of group prey capture, and social factors such as population density. A study confirmed the "hotshot hypothesis" of female aggregation formation in T. plumipes - the largest females attract the most males, and other females join the most attractive ones and form aggregations to increase their chances of attracting males. Smaller females are more likely to join other aggregations that are already established by larger females. The "preference model" is similarly supported with males showing preference for larger aggregations of females. Males settle within a larger aggregation because the distances between alternative females are minimized, allowing males to more easily and readily access potential females for mating. Due to the closely clustered nature of aggregations, the cost of searching for mates for males is reduced in a female aggregation. [11]
Maximum running speed and maximum climbing speed are positively related in T. plumipes. Spiders who are good runners are also good climbers. Climbing and running represent a single locomotive performance characteristic of T. plumipes. High performance in each might be promoted by the same morphological and physiological characteristics. There is no evidence of trade-off between fast running speeds and fast climbing speeds in T. plumipes. [16]
Orb-weaver spiders are members of the spider family Araneidae. They are the most common group of builders of spiral wheel-shaped webs often found in gardens, fields, and forests. The English word "orb" can mean "circular", hence the English name of the group. Araneids have eight similar eyes, hairy or spiny legs, and no stridulating organs.
Nephila is a genus of araneomorph spiders noted for the impressive webs they weave. Nephila consists of numerous species found in warmer regions around the world, although some species formerly included in the genus have been moved to Trichonephila. They are commonly called golden silk orb-weavers, golden orb-weavers, giant wood spiders, or banana spiders.
Trichonephila clavata, also known as the Joro spider (ジョロウグモ , is a member of the Trichonephila genus. The spider can be found throughout Japan, Korea, Taiwan, China. Due to its large size and the bright, unique colors of the female Trichonephila, the spider is well-favored in Japan.
Trichonephila clavipes, commonly known as the golden silk orb-weaver, golden silk spider, or colloquially banana spider, is an orb-weaving spider species which inhabits forests and wooded areas ranging from the southern US to Argentina. It is indigenous to both continental North and South America. Known for the golden color of their silk, the large size of their females, and their distinctive red-brown and yellow coloring, T. clavipes construct large, asymmetrical circular webs attached to trees and low shrubs in woods to catch small- and medium-size flying prey, mostly insects. They are excellent web-builders, producing and utilizing seven different types of silk, and they subdue their prey by injecting them with venom, as opposed to related species which immobilize their prey by wrapping them in silk first. They are not known to be aggressive towards humans, only biting out of self-defense if touched, and their relatively harmless venom has a low toxicity, posing little health concern to healthy human adults. Due to their prevalence in forests, T. clavipes may be encountered by hikers.
Argiope bruennichi is a species of orb-web spiders distributed throughout Central and Northern Europe, North Africa, parts of Asia, and the Azores archipelago. Like many other members of the genus Argiope, it has striking yellow and black markings on its abdomen.
Spider behavior refers to the range of behaviors and activities performed by spiders. Spiders are air-breathing arthropods that have eight legs and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms which is reflected in their large diversity of behavior.
Trichonephila edulis is a species of large spider of the family Nephilidae, formerly placed in the genus Nephila. It is referred to by the common name Australian golden orb weaver. It is found in Indonesia from Java eastwards, Papua New Guinea, Australia, northern New Zealand, and New Caledonia.
Nephila pilipes is a species of golden orb-web spider. It resides all over countries in East and Southeast Asia as well as Oceania. It is commonly found in primary and secondary forests and gardens. Females are large and grow to a body size of 30–50 mm, with males growing to 5–6 mm. It is the second largest of the orb-weaving spiders apart from the recently discovered Nephila komaci. The first, second, and fourth pairs of legs of juvenile females have dense hairy brushes, but these brushes disappear as the spider matures.
Sexual cannibalism is when an animal, usually the female, cannibalizes its mate prior to, during, or after copulation. It is a trait observed in many arachnid orders and several insect and crustacean clades. Several hypotheses to explain this seemingly paradoxical behavior have been proposed. The adaptive foraging hypothesis, aggressive spillover hypothesis and mistaken identity hypothesis are among the proposed hypotheses to explain how sexual cannibalism evolved. This behavior is believed to have evolved as a manifestation of sexual conflict, occurring when the reproductive interests of males and females differ. In many species that exhibit sexual cannibalism, the female consumes the male upon detection. Females of cannibalistic species are generally hostile and unwilling to mate; thus many males of these species have developed adaptive behaviors to counteract female aggression.
Cyrtophora citricola, also known as the tropical tent-web spider, is an orb-weaver spider in the family Araneidae. It is found in Asia, Africa, Australia, Costa Rica, Hispaniola, Colombia, and Southern Europe and in 2000, it was discovered in Florida. C. citricola differs from many of its close relatives due its ability to live in a wide variety of environments. In North America and South America, the spider has caused extensive damage to agricultural operations.
Darwin's bark spider is an orb-weaver spider that produces the largest known orb webs, ranging from 900 to 28,000 square centimetres, with bridge lines spanning up to 25 metres (82 ft). The spider was discovered in Madagascar in the Andasibe-Mantadia National Park in 2009. Its silk is the toughest biological material ever studied. Its tensile strength is 1.6 GPa. The species was named in honour of the naturalist Charles Darwin on November 24, 2009—precisely 150 years after the publication of The Origin of Species.
Pisaurina mira, also known as the American nursery web spider, is a species of spider in the family Pisauridae. They are often mistaken for wolf spiders (Lycosidae) due to their physical resemblance. P. mira is distinguished by its unique eye arrangement of two rows.
Argiope aemula, commonly known as the oval St Andrew's cross spider, is a species of spider in the family Araneidae which is native to southeast Asia, found from India and Sri Lanka to the Philippines, Indonesia, and Vanuatu. It is one of the giant, conspicuous "signature spider" species of the genus Argiope, observed in tropical and subtropical grasslands.
Nephilidae is a spider family commonly referred to as golden orb-weavers. The various genera in Nephilidae were formerly placed in Tetragnathidae and Araneidae. All nephilid genera partially renew their webs.
Agelenopsis pennsylvanica, commonly known as the Pennsylvania funnel-web spider or the Pennsylvania grass spider, is a species of spider in the family Agelenidae. The common name comes from the place that it was described, Pennsylvania, and the funnel shape of its web. Its closest relative is Agelenopsis potteri.
Argiope radon is a species of orb web spider native to Australia. It is found in tropical areas of the Northern Territory, Western Australia and Queensland. It is commonly known as the Northern St Andrew's cross spider.
Trichonephila is a genus of golden orb-weaver spiders that was first described by Friedrich Dahl in 1911, as a subgenus of Nephila. Trichonephila was elevated to the level of genus by Kuntner et al. in 2019. The genus Trichonephila belongs to the Nephilidae family.
Leucauge mariana is a long-jawed orb weaver spider, native to Central America and South America. Its web building and sexual behavior have been studied extensively. Males perform several kinds of courtship behavior to induce females to copulate and to use their sperm.
Pardosa pseudoannulata, a member of a group of species referred to as wolf-spiders, is a non-web-building spider belonging to the family Lycosidae. P. pseudoannulata are wandering spiders that track and ambush prey and display sexual cannibalism. They are commonly encountered in farmlands across China and other East Asian countries. Their venom has properties that helps it function as an effective insecticide, and it is, therefore, a crucial pesticide control agent.
Larinia jeskovi is a species of the family of orb weaver spiders and a part of the genus Larinia. It is distributed throughout the Americas, Africa, Australia, Europe, and Asia and commonly found in wet climes such as marshes, bogs, and rainforests. Larinia jeskovi have yellow bodies with stripes and range from 5.13 to 8.70 millimeters in body length. They build their webs on plants with a small height above small bodies of waters or wetlands. After sunset and before sunrise are the typical times they hunt and build their web. Males usually occupy a female's web instead of making their own. The mating behavior is noteworthy as male spiders often mutilate external female genitalia to reduce sperm competition while female spiders resort to sexual cannibalism to counter such mechanisms. The males also follow an elaborate courtship ritual to attract the female. The bite of Larinia jeskovi is not known to be of harm to humans.