Phidippus clarus
Encyclopedia
Phidippus clarus is a species
of jumping spider
(family
Salticidae) found in old fields throughout eastern North America
. It often waits upside down near the top of a plant, which may be useful for detecting prey, and then quickly jumps down before the prey can escape. The spider is one of 60 species in the genus
Phidippus
, and one of about 5,000 in the Salticidae, a family that accounts for about 10% of all spider species. P. clarus is a predator, mostly taking insects, other spiders, and other terrestrial arthropod
s.
Like other jumping spiders, it has vision more acute than a cat
and ten times more acute than a dragonfly
. The eyes are used to locate prey and rivals, and find and court mates. All spiders have sensors for smell, taste, touch and vibration protruding through their cuticle
("skin").
Jumping spiders can leap up to 50 times their own length by powerfully extending the third or fourth pairs of legs, with the longer forelimbs extended to grasp the prey. P. clarus, a relatively large salticid, takes prey up to the size of an adult earwig
. In an experiment, P. clarus was offered as many fruit flies
as it could eat, and in four-hour sessions individuals took 17 flies on average – while one took 41.
When P. clarus males compete for females, the winners are those that produce the most vibrations on the surface and those that are largest. Contests between females involve less displaying
, and physical fights between females are more likely to end in injury or death. The most successful males choose the largest females, as these produce the most eggs and most quickly. If a female that has mated already then finds a larger male, she will often mate again with the larger male. The average clutch
is 135 eggs. Unlike most of the genus Phidippus, P. clarus females die after one brood has left the nest.
P. clarus is parasitized
by the Californian
wasp
Aporinellus completus and by mermithid
nematode
s of the pseudo-genus Agamermis. In an experiment in 2006, P. clarus showed promise for controlling
the fourlined plant bug, Poecilocapsus lineatus, which severely damages the commercially-grown sweet basil.
Spiders are chelicerates, which differ from other arthropod
s in that the usual body segment
s are fused into only two tagmata
, the cephalothorax
and abdomen
. Jumping spiders have a distinctive rectangular carapace, and that of female Phidippus clarus average 4.05 millimetre (0.159448818897638 in) wide, while the carapaces of males average 3.2 millimetre (0.125984251968504 in). Spiders' abdomens bear appendages that have been modified into spinnerets that extrude silk
from up to six types of silk glands within their abdomen. The cephalothorax and abdomen are joined by a small, cylindrical pedicel
, which allows the abdomen to move while spinning silk
. While most jumping spiders do not build webs to catch prey, they use silk for other purposes, including molting and laying eggs.
Jumping spiders have large forelegs and short, powerful back legs. Unlike most arthropods, spiders have no extensor muscles in their limbs and instead extend them by increasing their blood pressure. Jumping spiders can leap several times their own length by powerfully extending the third or fourth pairs of legs, reaching up to 200 millimetres (7.9 in) with the forelimbs extended to grasp the prey.
Spiders maintain balance when walking, so that legs 1 and 3 on one side and 2 and 4 on the other move together, while the other four legs are on the surface. To run faster, spiders increase their stride length and frequency. However, P. Clarus and many other jumping spiders move on only six legs, using the front pair for other purposes.
In spiders and other chelicerates, there is only one pair of appendages before the mouth, and in spiders these are modified into fangs that inject poison into the prey. Behind the mouth is a pair of pedipalp
s ("palps" for short), and those of male spiders are quite large and are used for displaying and mating.
Spiders groom themselves regularly, and more often if wet or dirty. They moisten their fangs, draw the legs one at a time through the fangs, and "comb" the legs with the fangs and palps. The first and fourth pairs of legs are then used to groom other parts of the body, and the only place they appear not to reach is the dorsal surface of the carapace.
's and ten times more acute than a dragonfly
's. The main eyes focus accurately on objects at distances from approximately 2 centimetre (0.78740157480315 in) to infinity, and in practise can see up to about 75 cm (29.5 in).
Spiders, like other arthropod
s, have sensors, often modified setae (bristles), for smell, taste, touch and vibration, protruding through their cuticle
("skin"). Unlike insects, spiders and other chelicerates do not have antennae
.
safety line to the surface, using the two pairs of back legs to jump on the victim, and finally biting the prey. Most jumping spiders walk throughout the day, so that they maximize their chances of a catch.
After capturing the prey, P. clarus settles in one spot and does not move again until it has discarded the undigestible hard remains of the prey. If P. clarus has gone without food for a few days, it eats slowly.
P. clarus, which is large by the standards of salticids, takes prey up to the size of an adult earwig
. In an experiment, the jumping spider was offered as many fruit flies
as it could eat, and in 4-hour sessions specimens took 17 flies on average—while one took 41. When the courtship display of wolf spider
Schizocosa ocreata combines visual signals with vibrations, P. clarus responds to its wolf spider prey more quickly than when the wolf spider presents only one of the types of signal.
Before looking for a mate, a male spider spins a small, flat web on a surface and ejaculates into it. He then loads the semen
into syringe
-like receptacles in both palps, and then searches for a female.
Like other spider
s and many other arthropod
s, P. clarus can vibrate surfaces to interact with others of its species, sometimes in conjunction with other communications such as movements, to intimidate rivals and woo mates.
Competitions between P. clarus males occur on leaves up to 5 cm (2 in) long and wide, and the prize is the right to cohabit in the nest of a sub-adult female who is about enter her last molt and then become fertile. Initially the contending males use vibration and visual displays
, and the number of vibration signals often determines which male wins. Otherwise males may use "leg-fencing", trying to push each other backwards with their front legs and bodies. Some of these contests escalate to grappling, in which males lock chelicerae
(jaws) and legs for relatively longer periods. In contests, males with previous experience of winning are more likely to win later contests, and males with more experience of losing are more likely to lose in future. In both winners and losers, more recent experience is more important then much earlier experience. However, the weights of the contenders is a much stronger influence, and experience makes a difference only between individuals of similar size.
In contests between P. clarus females, the preliminaries are longer but ritualized displays are rare. Physical fights between females are more likely to end in injury or death.
Males of P. clarus can detect females' size and age based on pheromone
s and other chemicals left in females' silk, and males use this information to choose mates. Males prefer to cohabit with large females, which mature more quickly and have more offspring than smaller ones. The largest males are the most aggressive and thus the largest males and females mate, and so on in order
of size.
When P. clarus males find females, the males court
by waving their legs and making their abdomens vibrate against the substrate (leaves, the ground, etc.). Males will court
immature and adult virgin females, and also previously mated females. As the male dances, he approaches the female and touches the female cautiously once or twice. The female rejects the male by extending her first pair of legs whenever he approaches too closely, or shows acceptance by not blocking his advance. If accepted, the male climbs over her and uses his forelegs to turn her abdomen to the side. The turn exposes her genital pore, which lies on the underside of the abdomen, and the male inserts one semen-laden pedipalp. After two or three minutes the male withdraws this pedipalp, turns the female's abdomen the other way and inserts the other pedipalp.
Some P. clarus females mate with more than one male. In these females, copulations after the first occur after longer courtships. This shows that already-mated females are less receptive to mates, and suggests that females may be trading up in subsequent matings.
One mated female P. clarus can lay well over 100 eggs per sac, and many females lay more than one egg sac, in a thick silken cover. An average clutch contains 135 eggs. The egg membrane
is shed in 24–26 days, but the hatchlings (the first instar
) continue to mature in the cocoon. The first molt occurs 24–28 days after the membrane is shed, and two to three days later the spiderlings leave their protective cover and become active, independent individuals. They do not hunt immediately, even if prey is available, but spend several hours engaged in apparently random activity before seeking cover, where they remain between two hours and two days. About 10% of spiderlings build retreats during this period, while the rest do so only after they have fed.
Unlike most of the genus Phidippus, P. clarus females bear only one clutch of eggs, and usually die a few days after the spiderlings leave the nest. Males disappear a few weeks after females become mature.
. It lives among flowers, often sharing habitats with the small to medium-sized crab spider
Misumena vatia
, which waits for prey. P. clarus often waits upside down near the top of a plant, a position which may be useful for detecting prey and then quickly jumping down before the prey can escape. In a 2002 survey of jumping spiders in Minnesota
, P. clarus accounted for 52% of the total found.
The Californian
wasp
Aporinellus completus parasitizes P. clarus by paralyzing the spider and attaching an egg to the spider's abdomen. Mermithid
nematode
s of the pseudo-genus Agamermis infest P. clarus and many other spiders, typically severely damaging the main muscles, the digestive system and the reproductive system.
In an experiment in 2006, P. clarus showed promise for controlling
the fourlined plant bug, Poecilocapsus lineatus, which severely damages sweet basil, Ocimum basilicum, a herb commercially grown in greenhouse
s. The potential advantages of P. clarus for biocontrol include that the spider prefers to stay overnight in the same nest, detects prey visually from a distance, takes a wide range of prey, can both wait for prey and hunt actively, learns to recognize particular prey, and can be reared in individual cages. Although cannibalism
is likely to prevent mass rearing of P. clarus, it is possible to collect egg sacs or spiders and move them to where they are needed. In the breeding season, one mated female can lay well over 100 eggs per sac, many females lay more than one egg sac, and it is easy to recognize the egg sacs. Juvenile and adult jumping spiders can be collected via sweep netting or by providing good sites for nests, even in plumber
's tubing placed in old fields.
Phidippus
, and one of about 5,000 in the Salticidae, a family
that accounts for about 10% of all spider species. The name Salticidae is based on the Latin
saltus, meaning "a leap".
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...
of jumping spider
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...
(family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Salticidae) found in old fields throughout eastern North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. It often waits upside down near the top of a plant, which may be useful for detecting prey, and then quickly jumps down before the prey can escape. The spider is one of 60 species in the genus
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...
Phidippus
Phidippus
Phidippus is a genus in the family Salticidae . Some of the largest jumping spiders inhabit this genus, and many species are characterized by their brilliant, iridescent green chelicerae. Phidippus is distributed almost exclusively in North America, with the exception of two exported species...
, and one of about 5,000 in the Salticidae, a family that accounts for about 10% of all spider species. P. clarus is a predator, mostly taking insects, other spiders, and other terrestrial arthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s.
Like other jumping spiders, it has vision more acute than a cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
and ten times more acute than a dragonfly
Dragonfly
A dragonfly is a winged insect belonging to the order Odonata, the suborder Epiprocta or, in the strict sense, the infraorder Anisoptera . It is characterized by large multifaceted eyes, two pairs of strong transparent wings, and an elongated body...
. The eyes are used to locate prey and rivals, and find and court mates. All spiders have sensors for smell, taste, touch and vibration protruding through their cuticle
Cuticle
A cuticle , or cuticula, is a term used for any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticles" are non-homologous; differing in their origin, structure, function, and chemical composition...
("skin").
Jumping spiders can leap up to 50 times their own length by powerfully extending the third or fourth pairs of legs, with the longer forelimbs extended to grasp the prey. P. clarus, a relatively large salticid, takes prey up to the size of an adult earwig
Earwig
Earwigs make up the insect order Dermaptera, found throughout the Americas, Africa, Eurasia, Australia and New Zealand. With 1,800 species in 12 families, they are one of the smaller insect orders...
. In an experiment, P. clarus was offered as many fruit flies
Drosophila
Drosophila is a genus of small flies, belonging to the family Drosophilidae, whose members are often called "fruit flies" or more appropriately pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many species to linger around overripe or rotting fruit...
as it could eat, and in four-hour sessions individuals took 17 flies on average – while one took 41.
When P. clarus males compete for females, the winners are those that produce the most vibrations on the surface and those that are largest. Contests between females involve less displaying
Display (zoology)
Display is a form of animal behaviour, linked to survival of the species in various ways. One example of display used by some species can be found in the form of courtship, with the male usually having a striking feature that is distinguished by colour, shape or size, used to attract a female...
, and physical fights between females are more likely to end in injury or death. The most successful males choose the largest females, as these produce the most eggs and most quickly. If a female that has mated already then finds a larger male, she will often mate again with the larger male. The average clutch
Clutch (eggs)
A clutch of eggs refers to all the eggs produced by birds or reptiles, often at a single time, particularly those laid in a nest.In birds, destruction of a clutch by predators, , results in double-clutching...
is 135 eggs. Unlike most of the genus Phidippus, P. clarus females die after one brood has left the nest.
P. clarus is parasitized
Parasitism
Parasitism is a type of symbiotic relationship between organisms of different species where one organism, the parasite, benefits at the expense of the other, the host. Traditionally parasite referred to organisms with lifestages that needed more than one host . These are now called macroparasites...
by the Californian
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
wasp
Wasp
The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their...
Aporinellus completus and by mermithid
Mermithidae
Mermithidae is a family of nematode worms that are endoparasites in arthropods. As early as 1877, Mermithidae was listed as one of nine subdivisions of the Nematoidea. Mermithidae are confusable with the horsehair worms of the phylum Nematomorpha that have a similar life history and...
nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
s of the pseudo-genus Agamermis. In an experiment in 2006, P. clarus showed promise for controlling
BioControl
BioControl is a peer-reviewed scientific journal published by Springer Science+Business Media covering all aspects of basic and applied research in biological control of invertebrate, vertebrate, and weed pests, and plant diseases. The journal was established in 1956 as Entomophaga and published by...
the fourlined plant bug, Poecilocapsus lineatus, which severely damages the commercially-grown sweet basil.
Body structure
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s in that the usual body segment
Segmentation (biology)
Segmentation in biology refers to either a type of gastrointestinal motility or the division of some animal and plant body plans into a series of repetitive segments. This article will focus on the segmentation of animal body plans, specifically using the examples of the phyla Arthropoda,...
s are fused into only two tagmata
Tagma (biology)
In invertebrate biology, a tagma is a specialized grouping of arthropod segments, such as the head, the thorax, and the abdomen with a common function. The segments of a tagma may be either fused or moveable.-Tagmata:...
, 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...
. Jumping spiders have a distinctive rectangular carapace, and that of female Phidippus clarus average 4.05 millimetre (0.159448818897638 in) wide, while the carapaces of males average 3.2 millimetre (0.125984251968504 in). Spiders' abdomens bear appendages that have been modified into spinnerets that extrude silk
Spider silk
Spider silk is a protein fiber spun by spiders. Spiders use their silk to make webs or other structures, which function as nets to catch other animals, or as nests or cocoons for protection for their offspring...
from up to six types of silk glands within their abdomen. The cephalothorax and abdomen are joined by a small, cylindrical pedicel
Pedicel (spider)
The pedicel of a spider is a small, flexible cylinder that joins the cephalothorax and abdomen. This helps the spider to spin silk without moving the cephalothorax....
, which allows the abdomen to move while spinning silk
Spider silk
Spider silk is a protein fiber spun by spiders. Spiders use their silk to make webs or other structures, which function as nets to catch other animals, or as nests or cocoons for protection for their offspring...
. While most jumping spiders do not build webs to catch prey, they use silk for other purposes, including molting and laying eggs.
Jumping spiders have large forelegs and short, powerful back legs. Unlike most arthropods, spiders have no extensor muscles in their limbs and instead extend them by increasing their blood pressure. Jumping spiders can leap several times their own length by powerfully extending the third or fourth pairs of legs, reaching up to 200 millimetres (7.9 in) with the forelimbs extended to grasp the prey.
Spiders maintain balance when walking, so that legs 1 and 3 on one side and 2 and 4 on the other move together, while the other four legs are on the surface. To run faster, spiders increase their stride length and frequency. However, P. Clarus and many other jumping spiders move on only six legs, using the front pair for other purposes.
In spiders and other chelicerates, there is only one pair of appendages before the mouth, and in spiders these are modified into fangs that inject poison into the prey. Behind the mouth is a pair of 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 ("palps" for short), and those of male spiders are quite large and are used for displaying and mating.
Spiders groom themselves regularly, and more often if wet or dirty. They moisten their fangs, draw the legs one at a time through the fangs, and "comb" the legs with the fangs and palps. The first and fourth pairs of legs are then used to groom other parts of the body, and the only place they appear not to reach is the dorsal surface of the carapace.
Senses
Jumping spiders have eight eyes, the two large ones in the center-and-front position (the anterior-median eyes, also referred to as "principal eyes") providing acute vision and housed in tubes in the head. The other six are secondary eyes, positioned along the sides of the carapace and acting mainly as movement detectors. While other spiders can jump, salticids including Phidippus clarus are the only spiders with good vision, and their main eyes are more acute in daylight than a catCat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
's and ten times more acute than a dragonfly
Dragonfly
A dragonfly is a winged insect belonging to the order Odonata, the suborder Epiprocta or, in the strict sense, the infraorder Anisoptera . It is characterized by large multifaceted eyes, two pairs of strong transparent wings, and an elongated body...
's. The main eyes focus accurately on objects at distances from approximately 2 centimetre (0.78740157480315 in) to infinity, and in practise can see up to about 75 cm (29.5 in).
Spiders, like other arthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s, have sensors, often modified setae (bristles), for smell, taste, touch and vibration, protruding through their cuticle
Cuticle
A cuticle , or cuticula, is a term used for any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticles" are non-homologous; differing in their origin, structure, function, and chemical composition...
("skin"). Unlike insects, spiders and other chelicerates do not have antennae
Antenna (biology)
Antennae in biology have historically been paired appendages used for sensing in arthropods. More recently, the term has also been applied to cilium structures present in most cell types of eukaryotes....
.
Feeding
Almost all jumping spiders are predators, mostly preying on insects, other spiders, and other non-aquatic arthropods. The most common procedure is sighting the prey, stalking, fastening a silkSpider silk
Spider silk is a protein fiber spun by spiders. Spiders use their silk to make webs or other structures, which function as nets to catch other animals, or as nests or cocoons for protection for their offspring...
safety line to the surface, using the two pairs of back legs to jump on the victim, and finally biting the prey. Most jumping spiders walk throughout the day, so that they maximize their chances of a catch.
After capturing the prey, P. clarus settles in one spot and does not move again until it has discarded the undigestible hard remains of the prey. If P. clarus has gone without food for a few days, it eats slowly.
P. clarus, which is large by the standards of salticids, takes prey up to the size of an adult earwig
Earwig
Earwigs make up the insect order Dermaptera, found throughout the Americas, Africa, Eurasia, Australia and New Zealand. With 1,800 species in 12 families, they are one of the smaller insect orders...
. In an experiment, the jumping spider was offered as many fruit flies
Drosophila
Drosophila is a genus of small flies, belonging to the family Drosophilidae, whose members are often called "fruit flies" or more appropriately pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many species to linger around overripe or rotting fruit...
as it could eat, and in 4-hour sessions specimens took 17 flies on average—while one took 41. When the courtship display of wolf spider
Wolf spider
Wolf spiders are members of the family Lycosidae, from the Ancient Greek word "" meaning "wolf". They are robust and agile hunters with good eyesight. They live mostly solitary lives and hunt alone. Some are opportunistic hunters pouncing upon prey as they find it or even chasing it over short...
Schizocosa ocreata combines visual signals with vibrations, P. clarus responds to its wolf spider prey more quickly than when the wolf spider presents only one of the types of signal.
Reproduction and lifecycle
Phidippus clarus becomes adult in early summer, and females about to lay eggs can weight 400 milligram (0.0141095848420448 oz). Early in the breeding season, in early to mid July, there are more males than females. The females all become sexually mature at the same. At this point during this part of the breeding season males die off, so that the number of males becomes equal or slightly smaller than the number of females. By August, most females live in their nests overnight for increasing periods, as this is where they will lay eggs. The nests are located in rolled up leaves and are made of thick silk, which is expensive to build. Tests show that females use visual landmarks to return to their nests. A male only remains at the same nest when paired with a female.Before looking for a mate, a male spider spins a small, flat web on a surface and ejaculates into it. He then loads the semen
Semen
Semen is an organic fluid, also known as seminal fluid, that may contain spermatozoa. It is secreted by the gonads and other sexual organs of male or hermaphroditic animals and can fertilize female ova...
into syringe
Syringe
A syringe is a simple pump consisting of a plunger that fits tightly in a tube. The plunger can be pulled and pushed along inside a cylindrical tube , allowing the syringe to take in and expel a liquid or gas through an orifice at the open end of the tube...
-like receptacles in both palps, and then searches for a female.
Like other spider
Spider
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 and many other arthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s, P. clarus can vibrate surfaces to interact with others of its species, sometimes in conjunction with other communications such as movements, to intimidate rivals and woo mates.
Competitions between P. clarus males occur on leaves up to 5 cm (2 in) long and wide, and the prize is the right to cohabit in the nest of a sub-adult female who is about enter her last molt and then become fertile. Initially the contending males use vibration and visual displays
Display (zoology)
Display is a form of animal behaviour, linked to survival of the species in various ways. One example of display used by some species can be found in the form of courtship, with the male usually having a striking feature that is distinguished by colour, shape or size, used to attract a female...
, and the number of vibration signals often determines which male wins. Otherwise males may use "leg-fencing", trying to push each other backwards with their front legs and bodies. Some of these contests escalate to grappling, in which males lock 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...
(jaws) and legs for relatively longer periods. In contests, males with previous experience of winning are more likely to win later contests, and males with more experience of losing are more likely to lose in future. In both winners and losers, more recent experience is more important then much earlier experience. However, the weights of the contenders is a much stronger influence, and experience makes a difference only between individuals of similar size.
In contests between P. clarus females, the preliminaries are longer but ritualized displays are rare. Physical fights between females are more likely to end in injury or death.
Males of P. clarus can detect females' size and age based on pheromone
Pheromone
A pheromone is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting outside the body of the secreting individual to impact the behavior of the receiving individual...
s and other chemicals left in females' silk, and males use this information to choose mates. Males prefer to cohabit with large females, which mature more quickly and have more offspring than smaller ones. The largest males are the most aggressive and thus the largest males and females mate, and so on in order
Assortative mating
Assortative mating , and the related concept Disassortative mating, is the phenomenon where a sexually reproducing organism chooses to mate with individuals that are similar or dissimilar to itself in some specific manner...
of size.
When P. clarus males find females, the males court
Courtship
Courtship is the period in a couple's relationship which precedes their engagement and marriage, or establishment of an agreed relationship of a more enduring kind. In courtship, a couple get to know each other and decide if there will be an engagement or other such agreement...
by waving their legs and making their abdomens vibrate against the substrate (leaves, the ground, etc.). Males will court
Courtship
Courtship is the period in a couple's relationship which precedes their engagement and marriage, or establishment of an agreed relationship of a more enduring kind. In courtship, a couple get to know each other and decide if there will be an engagement or other such agreement...
immature and adult virgin females, and also previously mated females. As the male dances, he approaches the female and touches the female cautiously once or twice. The female rejects the male by extending her first pair of legs whenever he approaches too closely, or shows acceptance by not blocking his advance. If accepted, the male climbs over her and uses his forelegs to turn her abdomen to the side. The turn exposes her genital pore, which lies on the underside of the abdomen, and the male inserts one semen-laden pedipalp. After two or three minutes the male withdraws this pedipalp, turns the female's abdomen the other way and inserts the other pedipalp.
Some P. clarus females mate with more than one male. In these females, copulations after the first occur after longer courtships. This shows that already-mated females are less receptive to mates, and suggests that females may be trading up in subsequent matings.
One mated female P. clarus can lay well over 100 eggs per sac, and many females lay more than one egg sac, in a thick silken cover. An average clutch contains 135 eggs. The egg membrane
Biological membrane
A biological membrane or biomembrane is an enclosing or separatingmembrane that acts as a selective barrier, within or around a cell. It consists of a lipid bilayer with embedded proteins that may constitute close to 50% of membrane content...
is shed in 24–26 days, but the hatchlings (the first instar
Instar
An instar is a developmental stage of arthropods, such as insects, between each molt , until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, or...
) continue to mature in the cocoon. The first molt occurs 24–28 days after the membrane is shed, and two to three days later the spiderlings leave their protective cover and become active, independent individuals. They do not hunt immediately, even if prey is available, but spend several hours engaged in apparently random activity before seeking cover, where they remain between two hours and two days. About 10% of spiderlings build retreats during this period, while the rest do so only after they have fed.
Unlike most of the genus Phidippus, P. clarus females bear only one clutch of eggs, and usually die a few days after the spiderlings leave the nest. Males disappear a few weeks after females become mature.
Ecology
Phidippus clarus is found in old fields throughout eastern North AmericaNorth America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. It lives among flowers, often sharing habitats with the small to medium-sized crab spider
Crab spider
Crab spider is a common name applied loosely to many species of spiders, but most nearly consistently to members of the family Thomisidae...
Misumena vatia
Misumena vatia
Misumena vatia is a species of crab spider with holarctic distribution. In North America, where it is the largest and best-known flower spider, it is called the goldenrod crab spider or flower spider, because it is commonly found hunting in goldenrod sprays in the autumn.Young males in the early...
, which waits for prey. P. clarus often waits upside down near the top of a plant, a position which may be useful for detecting prey and then quickly jumping down before the prey can escape. In a 2002 survey of jumping spiders in Minnesota
Minnesota
Minnesota is a U.S. state located in the Midwestern United States. The twelfth largest state of the U.S., it is the twenty-first most populous, with 5.3 million residents. Minnesota was carved out of the eastern half of the Minnesota Territory and admitted to the Union as the thirty-second state...
, P. clarus accounted for 52% of the total found.
The Californian
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
wasp
Wasp
The term wasp is typically defined as any insect of the order Hymenoptera and suborder Apocrita that is neither a bee nor an ant. Almost every pest insect species has at least one wasp species that preys upon it or parasitizes it, making wasps critically important in natural control of their...
Aporinellus completus parasitizes P. clarus by paralyzing the spider and attaching an egg to the spider's abdomen. Mermithid
Mermithidae
Mermithidae is a family of nematode worms that are endoparasites in arthropods. As early as 1877, Mermithidae was listed as one of nine subdivisions of the Nematoidea. Mermithidae are confusable with the horsehair worms of the phylum Nematomorpha that have a similar life history and...
nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
s of the pseudo-genus Agamermis infest P. clarus and many other spiders, typically severely damaging the main muscles, the digestive system and the reproductive system.
In an experiment in 2006, P. clarus showed promise for controlling
BioControl
BioControl is a peer-reviewed scientific journal published by Springer Science+Business Media covering all aspects of basic and applied research in biological control of invertebrate, vertebrate, and weed pests, and plant diseases. The journal was established in 1956 as Entomophaga and published by...
the fourlined plant bug, Poecilocapsus lineatus, which severely damages sweet basil, Ocimum basilicum, a herb commercially grown in greenhouse
Greenhouse
A greenhouse is a building in which plants are grown. These structures range in size from small sheds to very large buildings...
s. The potential advantages of P. clarus for biocontrol include that the spider prefers to stay overnight in the same nest, detects prey visually from a distance, takes a wide range of prey, can both wait for prey and hunt actively, learns to recognize particular prey, and can be reared in individual cages. Although cannibalism
Cannibalism
Cannibalism is the act or practice of humans eating the flesh of other human beings. It is also called anthropophagy...
is likely to prevent mass rearing of P. clarus, it is possible to collect egg sacs or spiders and move them to where they are needed. In the breeding season, one mated female can lay well over 100 eggs per sac, many females lay more than one egg sac, and it is easy to recognize the egg sacs. Juvenile and adult jumping spiders can be collected via sweep netting or by providing good sites for nests, even in plumber
Plumber
A plumber is a tradesperson who specializes in installing and maintaining systems used for potable water, sewage, and drainage in plumbing systems. The term dates from ancient times, and is related to the Latin word for lead, "plumbum." A person engaged in fixing metaphorical "leaks" may also be...
's tubing placed in old fields.
Taxonomy
Phidippus clarus is one of the 60 species in the genusGenus
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...
Phidippus
Phidippus
Phidippus is a genus in the family Salticidae . Some of the largest jumping spiders inhabit this genus, and many species are characterized by their brilliant, iridescent green chelicerae. Phidippus is distributed almost exclusively in North America, with the exception of two exported species...
, and one of about 5,000 in the Salticidae, a family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
that accounts for about 10% of all spider species. The name Salticidae is based on the Latin
Latin
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...
saltus, meaning "a leap".