Araneus
Encyclopedia
Araneus is a genus
of common orb-weaving spiders. It includes about 650 species
, among which are the European garden spider
and the barn spider
.
among all of the orb-weaver family, with males being normally 1/3 to 1/4 the size of females. In A. diadematus, for example, last molt females can reach the body size of up to 1 in (2.5 cm), while most males seldom grow over 0.3 in (1 cm), both excluding legspan. Males are differentiated from females by a much smaller and more elongated abdomen, longer legs, and the inability to catch or consume prey bigger than self.
In females, the epigyne
has a long scape (a tongue-like appendage). Male pedipalp
s have a hook-like terminal apophysis
. Abdominal tubercles are present anterolaterally.
Araneus was originally called Epeira. The latter name is now considered a junior synonym of Araneus.
It was first coined by Charles Athanase Walckenaer
in 1805, for a range of spiders now considered Araneidae (orb-weavers). Over time, a rather diverse set of spiders was grouped under the genus Epeira, including species from the modern families Araneidae, Mimetidae (Mimetus syllepsicus described by Hentz
, 1832), Nephilidae
, Tetragnathidae, Theridiidae
, Theridiosomatidae (Theridiosoma gemmosum, described by L. Koch
, 1877 as Theridion gemmosum), Titanoecidae (Nurscia albomaculata, described by Lucas
, 1846 as Epeira albo-maculata) and Uloboridae (Uloborus glomosus, described by Walckenaer, 1842 as Epeira glomosus). Epeira cylindrica O. P-Cambridge
, 1889 was at a time placed in Linyphiidae
and is considered incertae sedis
, as is "Araneus" cylindriformis (Roewer
, 1942).
Epeira was synonymized with the genus Aranea by Leach
, 1815, and with Araneus by Simon
, 1904.
Throughout the 19th century, Epeira was used as a catch-all genus, similar to the once ubiquitous salticid genus Attus
. However, from 1911, to its last mention in 1957, only very few authors continued to use the genus in their publications, notably Franganillo (1913, 1918), Hingston (1932), Kaston (1948) and Marples (1957). Chamberlin & Ivie published a new species Epeira miniata in 1944, which was rejected.
Jean-Henri Fabre refers to Argiope
spiders as Epeira in his 1928 book "The Life of the Spider" (La Vie des araignées), within the family "Epeirae". James Henry Emerton
also uses the genus Epeira in his 1902 book "The Common Spiders of the United States", but refers to spiders mostly now considered Araneus. The popular 1893 book "American Spiders and their Spinningwork" by Henry Christopher McCook
also uses Epeira extensively.
The short documentary "Epeira diadema" (1952) by Italian director Alberto Ancilotto was nominated for an Oscar in 1953. It is about the spider today known as Araneus diadematus.
s, but will deliver a dry bite
on 8 out of 10 occasions. Females bite more often than males, who would rather flee or feign death.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of common orb-weaving spiders. It includes about 650 species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
, among which are the European garden spider
European garden spider
The European garden spider, diadem spider, cross spider, or cross orbweaver is a very common and well-known orb-weaver spider in Europe and parts of North America, in a range extending from New England and the Southeast to California and the northwestern United States and adjacent parts of...
and the barn spider
Barn spider
The barn spider is a nocturnal, yellow and brown spider with striped legs and a marking on its underside that is typically a black background with two white marks inside the black, although color ranges can be quite magnificent. It is about three quarters of an inch long with a large round abdomen...
.
Description
Spiders of this genus present perhaps the most obvious case of sexual dimorphismSexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...
among all of the orb-weaver family, with males being normally 1/3 to 1/4 the size of females. In A. diadematus, for example, last molt females can reach the body size of up to 1 in (2.5 cm), while most males seldom grow over 0.3 in (1 cm), both excluding legspan. Males are differentiated from females by a much smaller and more elongated abdomen, longer legs, and the inability to catch or consume prey bigger than self.
In females, the epigyne
Epigyne
The epigyne or epigynum is the external genital structure of female spiders. As the epigyne varies greatly in form in different species, even in closely related ones, it often provides the most distinctive characteristic for recognizing species...
has a long scape (a tongue-like appendage). Male pedipalp
Pedipalp
Pedipalps , are the second pair of appendages of the prosoma in the subphylum Chelicerata. They are traditionally thought to be homologous with mandibles in Crustacea and insects, although more recent studies Pedipalps (commonly shortened to palps or palpi), are the second pair of appendages of the...
s have a hook-like terminal apophysis
Apophysis
Apophysis is an open source fractal flame editor and renderer for Microsoft Windows.Apophysis has many features for creating and editing fractal flames, including an editor which allows one to directly edit the transforms by manipulating triangles, a mutations window, which applies random edits to...
. Abdominal tubercles are present anterolaterally.
Taxonomic history
It was first coined by Charles Athanase Walckenaer
Charles Athanase Walckenaer
Baron Charles Athanase Walckenaer was a French civil servant and scientist.-Biography:Walckenaer was born in Paris and studied at the universities of Oxford and Glasgow. In 1793 he was appointed head of the military transports in the Pyrenees, after which he pursued technical studies at the École...
in 1805, for a range of spiders now considered Araneidae (orb-weavers). Over time, a rather diverse set of spiders was grouped under the genus Epeira, including species from the modern families Araneidae, Mimetidae (Mimetus syllepsicus described by Hentz
Nicholas Marcellus Hentz
Nicholas Marcellus Hentz was a French American arachnologist. Hentz was born in Versailles, France. He immigrated to the United States in 1816 and became a pioneering zoologist in the field of arachnology....
, 1832), Nephilidae
Nephilidae
The Nephilidae are a spider family with 75 described species in four genera. They were formerly grouped in the families Araneidae and Tetragnathidae. The genus Singafrotypa was moved to Araneidae in 2002.All nephilid genera partially renew their webs....
, Tetragnathidae, Theridiidae
Theridiidae
Theridiidae is a large family of spiders, also known as the tangle-web spiders, cobweb spiders and comb-footed spiders. The diverse family includes over 2200 species in over 100 genera) of three-dimensional space-web-builders found throughout the world...
, Theridiosomatidae (Theridiosoma gemmosum, described by L. Koch
Ludwig Carl Christian Koch
Ludwig Carl Christian Koch was a German entomologist and arachnologist.He was born in Regensburg, Germany and died in Nuremberg, Germany. He studied in Nuremberg, initially law, but then turned to medicine and science...
, 1877 as Theridion gemmosum), Titanoecidae (Nurscia albomaculata, described by Lucas
Hippolyte Lucas
Pierre-Hippolyte Lucas was a French entomologist.Lucas was an assistant-naturalist at the Muséum national d'Histoire naturelle. From 1839 to 1842 he studied fauna as part of the scientific Commission on the exploration of Algeria.His brother was Prosper Lucas.-Works:*Histoire naturelle des...
, 1846 as Epeira albo-maculata) and Uloboridae (Uloborus glomosus, described by Walckenaer, 1842 as Epeira glomosus). Epeira cylindrica O. P-Cambridge
Octavius Pickard-Cambridge
The Reverend Octavius Pickard-Cambridge FRS was an English clergyman and zoologist.Pickard-Cambridge was born in Bloxworth rectory, Dorset, the fifth son of Revd George Pickard, rector and squire of Bloxworth: the family changed their name to Pickard-Cambridge in 1848...
, 1889 was at a time placed in Linyphiidae
Linyphiidae
Linyphiidae is a family of spiders, including more than 4,300 described species in 578 genera worldwide. This makes Linyphiidae the second largest family of spiders after the Salticidae. New species are still being discovered throughout the world, and the family is poorly known...
and is considered incertae sedis
Incertae sedis
, is a term used to define a taxonomic group where its broader relationships are unknown or undefined. Uncertainty at specific taxonomic levels is attributed by , , and similar terms.-Examples:*The fossil plant Paradinandra suecica could not be assigned to any...
, as is "Araneus" cylindriformis (Roewer
Carl Friedrich Roewer
Carl Friedrich Roewer was a German arachnologist. He concentrated on harvestmen, where he described almost a third of today's known species, but also almost 700 taxa of spiders and numerous Solifugae....
, 1942).
Epeira was synonymized with the genus Aranea by Leach
William Elford Leach
William Elford Leach FRS was an English zoologist and marine biologist.Leach was born at Hoe Gate, Plymouth, the son of a solicitor. At the age of twelve he went to school in Exeter, studying anatomy and chemistry. By this time he was already collecting marine samples from Plymouth Sound and along...
, 1815, and with Araneus by Simon
Eugène Simon
Eugène Simon was a French arachnologist. His many taxonomic contributions include categorizing and naming many spiders, as well as creating genera such as Anelosimus, Psellocoptus and Phlogius....
, 1904.
Throughout the 19th century, Epeira was used as a catch-all genus, similar to the once ubiquitous salticid genus Attus
Attus
Attus is a deprecated spider genus that is now considered a junior synonym of Salticus. In the 18th and early 19th centuries, the majority of jumping spiders were grouped under the name Attus....
. However, from 1911, to its last mention in 1957, only very few authors continued to use the genus in their publications, notably Franganillo (1913, 1918), Hingston (1932), Kaston (1948) and Marples (1957). Chamberlin & Ivie published a new species Epeira miniata in 1944, which was rejected.
Jean-Henri Fabre refers to Argiope
Argiope (spider)
The genus Argiope includes rather large and spectacular spiders that have often a strikingly coloured abdomen. These are well distributed throughout the world, and most countries in temperate or warmer climates have one or more species, which look similar....
spiders as Epeira in his 1928 book "The Life of the Spider" (La Vie des araignées), within the family "Epeirae". James Henry Emerton
James Henry Emerton
James Henry Emerton was an American arachnologist.-Early life:Emerton was born at Salem, Massachusetts, on March 31, 1847. He was rather frail, and a young helper in his father's drug store, George F. Markoe, interested the boy in outdoor life...
also uses the genus Epeira in his 1902 book "The Common Spiders of the United States", but refers to spiders mostly now considered Araneus. The popular 1893 book "American Spiders and their Spinningwork" by Henry Christopher McCook
Henry Christopher McCook
Henry Christopher McCook was an American Presbyterian clergyman, naturalist, and prolific author on religion, history, and nature. He was a member of the celebrated Fighting McCooks, a family of Ohio military officers and volunteers during the American Civil War.-Biography:McCook was born in New...
also uses Epeira extensively.
The short documentary "Epeira diadema" (1952) by Italian director Alberto Ancilotto was nominated for an Oscar in 1953. It is about the spider today known as Araneus diadematus.
Venom
Araneus spiders possess various venomVenom
Venom is the general term referring to any variety of toxins used by certain types of animals that inject it into their victims by the means of a bite or a sting...
s, but will deliver a dry bite
Dry bite
A dry bite is a bite by a venomous animal in which no venom is released. Dry snake bites are called "Venomous snake bite without envenoming". Dry bites can occur from all snakes, but their frequency varies from species to species. For example, brown snakes can inflict dry bites 80% of the time...
on 8 out of 10 occasions. Females bite more often than males, who would rather flee or feign death.
See also
- List of Araneus species
External links
- Image of variations in A. trifolium (from Spider myths)
- Pictures of US Araneus species (free for noncommercial use)
- Pictures of A. trifolium (free for noncommercial use)
