Zygoballus sexpunctatus
Encyclopedia
Zygoballus sexpunctatus is a species of jumping spider
which occurs in the southeastern United States
where it can be found in a variety of grassy habitats. Adult spiders measure between 3 and 4.5 mm in length. The cephalothorax
and abdomen
are bronze to black in color, with reddish brown or yellowish legs. The male has distinctive enlarged chelicerae
(the mouthparts used for grasping prey) and front femora
(the third, and typically largest, leg segments). Like many jumping spiders, Z. sexpunctatus males exhibit ritualized courtship
and agonistic behavior.
sex meaning "six" and punctum meaning "spot". This is a reference to the six spots typically occurring on the abdomen of the male.
in 1845 in the Boston Journal of Natural History
. Hentz named the species Attus
sexpunctatus and described it as follows:
Hentz classified A. sexpunctatus in the subgeneric
group Pugnatoriae, which consisted of jumping spiders whose first pair of legs were the longest, followed by the fourth pair. Later entomologists abandoned this classification
, which Hentz himself admitted was "somewhat artificial". In 1888, with the recognition of Zygoballus
as an independent genus, American arachnologists George and Elizabeth Peckham
renamed the spider Zygoballus sexpunctatus. Specimens of Z. sexpunctatus are housed at the Museum of Comparative Zoology
, the British Museum
, the Milwaukee Public Museum
, the American Museum of Natural History
, and the Museum National d'Histoire Naturelle
. No type specimens
are known.
The genus Zygoballus contains approximately twenty species distributed from the United States
to Argentina
. Zygoballus is classified in the subfamily Dendryphantinae
of the family Salticidae (jumping spiders).
, adult females are 3.5 to 4.5 mm in body length, while males are 3 to 3.5 mm. The Peckhams'
earlier description, however, gives a length of 3 mm for females and 3 to 4.5 mm for males.
The cephalothorax
of Z. sexpunctatus is bronze to black in color. Like all Zygoballus spiders, the cephalothorax is box-like in shape, being widest at the posterior lateral eyes. Numerous white or pale blue scales cover the clypeus
("face") and chelicerae
. This covering extends around the sides of the carapace, ending beyond the posterior median eyes. In males, the labium is two-fifths as long as the maxillae, and as wide as it is long. The chelicerae of males are greatly enlarged and obliquely oriented, with each chelicera having a prominent inner tooth and a long, curved fang.
The legs are reddish brown, or sometimes yellowish, with the femora
of the anterior (first) pair being darker and enlarged, especially in the male. The anterior legs have three pairs of long spines on the ventral surface of the tibia
and two pairs of spines on the metatarsus
. The Peckhams give the following measurements for the lengths of the legs of a male specimen, starting with the anterior pair: 3.7 mm, 2.2 mm, 2 mm, 3 mm. In females, the fourth pair of legs are the longest. The pedipalp
in the male has a single tibial apophysis which tapers gradually.
The abdomen
is bronze to black with a white basal band and two white transverse bands. The transverse bands are often broken to form six spots. Some or all of these spots may be lacking, however.
Zygoballus sexpunctatus is similar in appearance to Zygoballus rufipes
, with whom its range overlaps. The male can be distinguished from Z. rufipes by the large spot of white scales at the beginning of the thoracic slope (which is lacking in Z. rufipes), and by the longitudinal division present on the bulb of the pedipalp (Z. rufipes has a transverse division). The female can best be distinguished by the form of the epigyne
(the external genital structure).
to Florida
and west to Texas
, although it is most commonly found in the southern states. Hentz collected his original specimen in North Carolina. In 1909, the Peckhams reported that the species had been collected from North Carolina, Florida, Texas, Louisiana, and Mississippi. A seven-year survey of spider species in western Mississippi
reported the abundance of Z. sexpunctatus as "uncommon". A one-year survey in Alachua County, Florida
, reported the species as "rare".
Specimens have been collected from several different ecosystems, including old field
s, river terrace forests, flatwoods
, Florida Sand Pine scrub
, Slash Pine
forests, Appalachian grass balds
, and rice fields. Robert and Betty Barnes reported the species as occurring in broomsedge
fields throughout the southeastern Piedmont
. The species is typically found in the herb stratum (among grasses and other short plants) and may be collected with a sweep net.
s. As a male approaches a female, it will typically raise and spread its first pair of legs and vibrate its abdomen. If the female is receptive, it will often vibrate its abdomen as well. The specific patterns of courtship behavior, however, vary between individuals.
Z. sexpunctatus males exhibit ritualized agonistic behavior when encountering other males of the same species. This behavior may include many of the same elements as courtship, such as raising and spreading the first pair of legs and vibrating the abdomen. During agonistic display, males will also extend their pedipalps and fangs. Lethal attacks between males appear to be rare, however.
s, Zygoballus sexpunctatus is an opportunistic feeder, feeding on a wide range of invertebrate
prey. The spider's diet typically includes small insect
s such as aphid
s and young caterpillar
s. They have also been known to eat mosquito
es and numerous kinds of small spiders.
Mud dauber wasps
, which capture and paralyze spiders as a source of food for their larvae, have been shown to prey on both male and female Z. sexpunctatus spiders.
, Zygoballus sexpunctatus spiderlings were reported to hatch from egg sacs in mid summer. The spiders hibernated through the winter in an immature form and reached sexual maturity
around late April.
Jumping spider
The jumping spider family contains more than 500 described genera and about 5,000 described species, making it the largest family of spiders with about 13% of all species. Jumping spiders have some of the best vision among invertebrates and use it in courtship, hunting and navigation...
which occurs in the southeastern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
where it can be found in a variety of grassy habitats. Adult spiders measure between 3 and 4.5 mm in length. The cephalothorax
Cephalothorax
The cephalothorax is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. The word cephalothorax is derived from the Greek words for head and thorax...
and abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
are bronze to black in color, with reddish brown or yellowish legs. The male has distinctive enlarged chelicerae
Chelicerae
The chelicerae are mouthparts of the Chelicerata, an arthropod subphylum that includes arachnids, Merostomata , and Pycnogonida . Chelicerae are pointed appendages which are used to grasp food, and are found in place of the chewing mandibles most other arthropods have...
(the mouthparts used for grasping prey) and front femora
Arthropod leg
The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments are of Latin origin, and may be confused with terms for bones: coxa , trochanter , femur, tibia, tarsus, ischium, metatarsus, carpus, dactylus ,...
(the third, and typically largest, leg segments). Like many jumping spiders, Z. sexpunctatus males exhibit ritualized courtship
Courtship display
Courtship display is a special, sometimes ritualised, set of behaviours which some animals perform as part of courtship. Courtship behaviours can include special calls, postures, and movements, and may involve special plumage, bright colours or other ornamentation. A good example is the 'dancing'...
and agonistic behavior.
Etymology
The specific name is derived from the LatinLatin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
sex meaning "six" and punctum meaning "spot". This is a reference to the six spots typically occurring on the abdomen of the male.
History and taxonomy
The species was first described by entomologist Nicholas Marcellus HentzNicholas 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....
in 1845 in the Boston Journal of Natural History
Boston Journal of Natural History
The Boston Journal of Natural History was a scholarly journal published by the Boston Society of Natural History in mid-19th century Massachusetts. Contributors included Charles T. Jackson, Augustus A. Gould, and others. Each volume featured lithographic illustrations, some in color,...
. Hentz named the species 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....
sexpunctatus and described it as follows:
"Black; cephalothorax with the two posterior eyes near the base, which is wide and suddenly inclined at nearly a right angle with the upper surface, cheliceres with a strong inner tooth, and a long, curved fang; abdomen with six dots, and a line in front, white; feet, 1. 4. 2. 3., first pair with enlarged thighs and quite long."
Hentz classified A. sexpunctatus in the subgeneric
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
group Pugnatoriae, which consisted of jumping spiders whose first pair of legs were the longest, followed by the fourth pair. Later entomologists abandoned this classification
Biological classification
Biological classification, or scientific classification in biology, is a method to group and categorize organisms by biological type, such as genus or species. Biological classification is part of scientific taxonomy....
, which Hentz himself admitted was "somewhat artificial". In 1888, with the recognition of Zygoballus
Zygoballus
Zygoballus is a genus of jumping spiders found in North and South America.-Taxonomy and history:The genus was first described in 1885 by American arachnologists George and Elizabeth Peckham based on the type species Zygoballus rufipes...
as an independent genus, American arachnologists George and Elizabeth Peckham
George and Elizabeth Peckham
George Williams Peckham and Elizabeth Maria Gifford Peckham were early American teachers, taxonomists, ethologists, arachnologists, and entomologists, specializing in animal behavior and in the study of jumping spiders and wasps.-Lives and careers:George Peckham was born in Albany,...
renamed the spider Zygoballus sexpunctatus. Specimens of Z. sexpunctatus are housed at the Museum of Comparative Zoology
Museum of Comparative Zoology
The Museum of Comparative Zoology, full name "The Louis Agassiz Museum of Comparative Zoology", often abbreviated simply to "MCZ", is a zoology museum located on the grounds of Harvard University in Cambridge, Massachusetts. It is one of three museums which collectively comprise the Harvard Museum...
, the British Museum
British Museum
The British Museum is a museum of human history and culture in London. Its collections, which number more than seven million objects, are amongst the largest and most comprehensive in the world and originate from all continents, illustrating and documenting the story of human culture from its...
, the Milwaukee Public Museum
Milwaukee Public Museum
The Milwaukee Public Museum is a natural and human history museum located in downtown Milwaukee, Wisconsin, USA. The museum was chartered in 1882 and opened to the public in 1884; it is a not-for-profit organization operated by the Milwaukee Public Museum, Inc. MPM has three floors of exhibits...
, the American Museum of Natural History
American Museum of Natural History
The American Museum of Natural History , located on the Upper West Side of Manhattan in New York City, United States, is one of the largest and most celebrated museums in the world...
, and the Museum National d'Histoire Naturelle
Muséum national d'histoire naturelle
The Muséum national d'Histoire naturelle is the National Museum of Natural History in Paris, France.- History :The museum was formally founded on 10 June 1793, during the French Revolution...
. No type specimens
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
are known.
The genus Zygoballus contains approximately twenty species distributed from the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
to Argentina
Argentina
Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...
. Zygoballus is classified in the subfamily Dendryphantinae
Dendryphantinae
The Dendryphantinae are a subfamily of jumping spiders that occur mainly in the New World. The females generally show paired spots on the abdomen, and the males often have enlarged chelicerae...
of the family Salticidae (jumping spiders).
Description
According to arachnologist B. J. KastonBenjamin J. Kaston
Benjamin Julian Kaston was an American arachnologist.Kaston was born in New York City and graduated from North Carolina State University in 1930. In 1934, he earned a PhD in zoology from Yale University, where he first began studying spiders...
, adult females are 3.5 to 4.5 mm in body length, while males are 3 to 3.5 mm. The Peckhams'
George and Elizabeth Peckham
George Williams Peckham and Elizabeth Maria Gifford Peckham were early American teachers, taxonomists, ethologists, arachnologists, and entomologists, specializing in animal behavior and in the study of jumping spiders and wasps.-Lives and careers:George Peckham was born in Albany,...
earlier description, however, gives a length of 3 mm for females and 3 to 4.5 mm for males.
The cephalothorax
Cephalothorax
The cephalothorax is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. The word cephalothorax is derived from the Greek words for head and thorax...
of Z. sexpunctatus is bronze to black in color. Like all Zygoballus spiders, the cephalothorax is box-like in shape, being widest at the posterior lateral eyes. Numerous white or pale blue scales cover the clypeus
Clypeus
The clypeus is one of the sclerites that makes up the "face" of an arthropod.In insects, the clypeus delimits the lower margin of the face, with the labrum articulated along the ventral margin of the clypeus. The mandibles bracket the labrum, but do not touch the clypeus. The dorsal margin of the...
("face") and chelicerae
Chelicerae
The chelicerae are mouthparts of the Chelicerata, an arthropod subphylum that includes arachnids, Merostomata , and Pycnogonida . Chelicerae are pointed appendages which are used to grasp food, and are found in place of the chewing mandibles most other arthropods have...
. This covering extends around the sides of the carapace, ending beyond the posterior median eyes. In males, the labium is two-fifths as long as the maxillae, and as wide as it is long. The chelicerae of males are greatly enlarged and obliquely oriented, with each chelicera having a prominent inner tooth and a long, curved fang.
The legs are reddish brown, or sometimes yellowish, with the femora
Arthropod leg
The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments are of Latin origin, and may be confused with terms for bones: coxa , trochanter , femur, tibia, tarsus, ischium, metatarsus, carpus, dactylus ,...
of the anterior (first) pair being darker and enlarged, especially in the male. The anterior legs have three pairs of long spines on the ventral surface of the tibia
Arthropod leg
The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments are of Latin origin, and may be confused with terms for bones: coxa , trochanter , femur, tibia, tarsus, ischium, metatarsus, carpus, dactylus ,...
and two pairs of spines on the metatarsus
Arthropod leg
The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments are of Latin origin, and may be confused with terms for bones: coxa , trochanter , femur, tibia, tarsus, ischium, metatarsus, carpus, dactylus ,...
. The Peckhams give the following measurements for the lengths of the legs of a male specimen, starting with the anterior pair: 3.7 mm, 2.2 mm, 2 mm, 3 mm. In females, the fourth pair of legs are the longest. The 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...
in the male has a single tibial apophysis which tapers gradually.
The abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
is bronze to black with a white basal band and two white transverse bands. The transverse bands are often broken to form six spots. Some or all of these spots may be lacking, however.
Zygoballus sexpunctatus is similar in appearance to Zygoballus rufipes
Zygoballus rufipes
Zygoballus rufipes, commonly called the hammerjawed jumper, is a species of jumping spider which occurs in the United States, Canada, and Central America. Adult females are 4.3 to 6 mm in body length, while males are 3 to 4 mm.-Taxonomy:...
, with whom its range overlaps. The male can be distinguished from Z. rufipes by the large spot of white scales at the beginning of the thoracic slope (which is lacking in Z. rufipes), and by the longitudinal division present on the bulb of the pedipalp (Z. rufipes has a transverse division). The female can best be distinguished by the form of 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...
(the external genital structure).
Habitat and distribution
The range of the species extends from New JerseyNew Jersey
New Jersey is a state in the Northeastern and Middle Atlantic regions of the United States. , its population was 8,791,894. It is bordered on the north and east by the state of New York, on the southeast and south by the Atlantic Ocean, on the west by Pennsylvania and on the southwest by Delaware...
to Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
and west to Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
, although it is most commonly found in the southern states. Hentz collected his original specimen in North Carolina. In 1909, the Peckhams reported that the species had been collected from North Carolina, Florida, Texas, Louisiana, and Mississippi. A seven-year survey of spider species in western Mississippi
Mississippi
Mississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...
reported the abundance of Z. sexpunctatus as "uncommon". A one-year survey in Alachua County, Florida
Alachua County, Florida
Alachua County is a county located in the U.S. state of Florida. The U.S. Census Bureau 2006 estimate for the county is 227,120. Its county seat is Gainesville, Florida. Alachua County is the home of the University of Florida and is also known for its diverse culture, local music, and artisans...
, reported the species as "rare".
Specimens have been collected from several different ecosystems, including old field
Old field (ecology)
Old field is a term used in ecology to describe lands formerly cultivated or grazed but later abandoned. The dominant flora include grasses, heaths and herbaceous plants, with encroaching woody vegetation. It represents an intermediate stage found in ecological succession in an ecosystem advancing...
s, river terrace forests, flatwoods
Flatwoods
Flatwoods, Pineywoods, Longleaf Pine-Wiregrass Ecosystem refers to an ecological community in the Southeastern coastal plain of North America...
, Florida Sand Pine scrub
Florida scrub
Florida scrub is an endangered temperate coniferous forest ecoregion of the state of Florida in the United States. It is found on coastal and inland sand ridges and is characterized by a xeromorphic plant community dominated by shrubs and dwarf oaks. Scrub soils, a type of entisol, are derived...
, Slash Pine
Slash Pine
Pinus elliottii, commonly known as the Slash Pine, is a pine native to the southeastern United States, from southern South Carolina west to southeastern Louisiana, and south to the Florida Keys....
forests, Appalachian grass balds
Appalachian balds
In the Appalachian Mountains of the eastern United States, balds are mountain summits or crests covered primarily by thick vegetation of native grasses or shrubs occurring in areas where heavy forest growth would be expected....
, and rice fields. Robert and Betty Barnes reported the species as occurring in broomsedge
Andropogon
Andropogon is a genus of grasses. Andropogon gerardii, big bluestem, is the official state grass of Illinois.Broomsedge is found along the eastern United States...
fields throughout the southeastern Piedmont
Piedmont (United States)
The Piedmont is a plateau region located in the eastern United States between the Atlantic Coastal Plain and the main Appalachian Mountains, stretching from New Jersey in the north to central Alabama in the south. The Piedmont province is a physiographic province of the larger Appalachian division...
. The species is typically found in the herb stratum (among grasses and other short plants) and may be collected with a sweep net.
Behavior
Male Zygoballus sexpunctatus spiders are known to exhibit elaborate courtship displayCourtship display
Courtship display is a special, sometimes ritualised, set of behaviours which some animals perform as part of courtship. Courtship behaviours can include special calls, postures, and movements, and may involve special plumage, bright colours or other ornamentation. A good example is the 'dancing'...
s. As a male approaches a female, it will typically raise and spread its first pair of legs and vibrate its abdomen. If the female is receptive, it will often vibrate its abdomen as well. The specific patterns of courtship behavior, however, vary between individuals.
Z. sexpunctatus males exhibit ritualized agonistic behavior when encountering other males of the same species. This behavior may include many of the same elements as courtship, such as raising and spreading the first pair of legs and vibrating the abdomen. During agonistic display, males will also extend their pedipalps and fangs. Lethal attacks between males appear to be rare, however.
Diet and ecology
Like most spiderSpider
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...
s, Zygoballus sexpunctatus is an opportunistic feeder, feeding on a wide range of invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
prey. The spider's diet typically includes small insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s such as aphid
Aphid
Aphids, also known as plant lice and in Britain and the Commonwealth as greenflies, blackflies or whiteflies, are small sap sucking insects, and members of the superfamily Aphidoidea. Aphids are among the most destructive insect pests on cultivated plants in temperate regions...
s and young caterpillar
Caterpillar
Caterpillars are the larval form of members of the order Lepidoptera . They are mostly herbivorous in food habit, although some species are insectivorous. Caterpillars are voracious feeders and many of them are considered to be pests in agriculture...
s. They have also been known to eat mosquito
Mosquito
Mosquitoes are members of a family of nematocerid flies: the Culicidae . The word Mosquito is from the Spanish and Portuguese for little fly...
es and numerous kinds of small spiders.
Mud dauber wasps
Mud dauber
Mud dauber is a name commonly applied to a number of wasps from either the family Sphecidae or Crabronidae that build their nests from mud...
, which capture and paralyze spiders as a source of food for their larvae, have been shown to prey on both male and female Z. sexpunctatus spiders.
Life cycle
In a study of spider populations in western TennesseeTennessee
Tennessee is a U.S. state located in the Southeastern United States. It has a population of 6,346,105, making it the nation's 17th-largest state by population, and covers , making it the 36th-largest by total land area...
, Zygoballus sexpunctatus spiderlings were reported to hatch from egg sacs in mid summer. The spiders hibernated through the winter in an immature form and reached sexual maturity
Sexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
around late April.
External links
- Zygoballus sexpunctatus at Worldwide database of jumping spiders
- Zygoballus sexpunctatus at Global Species Database of Salticidae (Araneae)
- Zygoballus sexpunctatus at Salticidae: Diagnostic Drawings Library
- Zygoballus sexpunctatus at The Nearctic Spider Database
- Zygoballus sexpunctatus at Bugguide.net
- Behavior of Zygoballus sexpunctatus jumping spiders (video)
- Interactions of male and female Zygoballus sexpunctatus jumping spiders (video)