Menemerus bivittatus
Encyclopedia
Menemerus bivittatus is a spider in the Salticidae family commonly known as the gray wall jumper. It is a pantropical
species and is usually found on the walls of buildings or on tree trunks where it stalks its prey
.
in distribution being common in most tropical regions. In North America, the species is found in Florida, Texas and California and south as far as Paraguay. It is often seen on the outside of man-made structures.
and chelicerae
are also black and white and the legs have transverse bandings of the same colours. The female is generally paler and more brown, with a larger carapace and abdomen. Her carapace is edged with two black bands and a thin white stripe and her abdomen is edged with broad black stripes on each side which unite at the posterior end. Her legs are banded but are paler than those of the male. Immature spiders resemble the female.
Both young and old spiders feed mainly on small flies which alight on walls. They do not build a web but instead, stalk their prey before launching an attack by leaping on the victim. They have high visual acuity and their large eyes are able to focus on objects and detect different colours. They use their highly coordinated jumping ability to capture their prey and to move from one place to another. They are capable of capturing insects such as crane flies that are at least twice their own size.
Male spiders of this species possess a stridulatory apparatus
which consists of several long bristles on the palpal femur and a series of horizontal ridges on the outer side of the chelicerae. Sound is generated when the spider rubs these ridges up and down against the palpal teeth. This is believed to be part of a courtship display
by the male.
In India this common spider is found on the outer walls of buildings and on tree trunks. It moves actively about in search of small insect prey, often vibrating its hairy palps as it walks. In the Gambia, spiders of this species have been observed loitering near and observing the entrances to nests of stingless bees. It is difficult for the spider to catch the bees as they fly out of the entrance but the bees are more vulnerable when returning to the nest.
Pantropical
In biogeography, a pantropical distribution one which covers tropical regions of all of the major continents, i.e. in Africa, in Asia and in the Americas. Examples include the plant genera Acacia and Bacopa....
species and is usually found on the walls of buildings or on tree trunks where it stalks its prey
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
.
Distribution
Menemerus bivittatus is cosmopolitanCosmopolitan distribution
In biogeography, a taxon is said to have a cosmopolitan distribution if its range extends across all or most of the world in appropriate habitats. For instance, the killer whale has a cosmopolitan distribution, extending over most of the world's oceans. Other examples include humans, the lichen...
in distribution being common in most tropical regions. In North America, the species is found in Florida, Texas and California and south as far as Paraguay. It is often seen on the outside of man-made structures.
Description
Gray wall jumpers are dorso-ventrally flattened and are covered with short dense, grayish-white hairs. There are tufts of dark brown bristles near the large, forward-facing eyes. The spiders are about nine millimetres long, the male being slightly smaller than the female. The male has a blackish longitudinal dorsal stripe with a brownish-white stripe on either side of the abdomen. The carapaceCarapace
A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...
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...
are also black and white and the legs have transverse bandings of the same colours. The female is generally paler and more brown, with a larger carapace and abdomen. Her carapace is edged with two black bands and a thin white stripe and her abdomen is edged with broad black stripes on each side which unite at the posterior end. Her legs are banded but are paler than those of the male. Immature spiders resemble the female.
Biology
The female gray wall jumper builds an eggsac in a crack or other concealed position in which she lays 25 to 40 eggs in a purse-like silken case. She guards the eggs until they hatch in about three weeks time after which the young spiders disperse.Both young and old spiders feed mainly on small flies which alight on walls. They do not build a web but instead, stalk their prey before launching an attack by leaping on the victim. They have high visual acuity and their large eyes are able to focus on objects and detect different colours. They use their highly coordinated jumping ability to capture their prey and to move from one place to another. They are capable of capturing insects such as crane flies that are at least twice their own size.
Male spiders of this species possess a stridulatory apparatus
Stridulation
Stridulation is the act of producing sound by rubbing together certain body parts. This behavior is mostly associated with insects, but other animals are known to do this as well, such as a number of species of fishes, snakes and spiders...
which consists of several long bristles on the palpal femur and a series of horizontal ridges on the outer side of the chelicerae. Sound is generated when the spider rubs these ridges up and down against the palpal teeth. This is believed to be part of a courtship display
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'...
by the male.
In India this common spider is found on the outer walls of buildings and on tree trunks. It moves actively about in search of small insect prey, often vibrating its hairy palps as it walks. In the Gambia, spiders of this species have been observed loitering near and observing the entrances to nests of stingless bees. It is difficult for the spider to catch the bees as they fly out of the entrance but the bees are more vulnerable when returning to the nest.