Myrmarachne melanotarsa
Encyclopedia
Myrmarachne melanotarsa, the dark-footed ant-spider, is an African jumping spider
found around Lake Victoria
in Africa
. Like other spiders in the genus Myrmarachne
, these spider
s mimic
ant
s, in this case, ants of the Crematogaster
genus. However, they are unusual in that they exhibit some form of social behavior
, forming clusters of silk
nests on fig
and other trees. Hundreds of these spiders, of both sexes and of all ages, can be found in such communal nests, but most nests have between 10 and 50 spiders. The Crematogaster ants which they mimic are often found in the nests with the spiders, along with other species of jumping spider.
Some predators (including larger jumping spiders) eat jumping spiders but are averse to attacking ants, as ants aggressively defend themselves. M. melanotarsa takes advantage of this aversion by mimicking the ants. Spiders of the genera Menemerus
and Pseudicius
have been shown to flee, leaving their eggs behind, when in the presence of groups of M. melanotarsa. M. melanotarsa is known to eat the eggs of such spiders. However, individuals or small groups of M. melanotarsa may be attacked and eaten by these predators who fear large groups.
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...
found around Lake Victoria
Lake Victoria
Lake Victoria is one of the African Great Lakes. The lake was named for Queen Victoria of the United Kingdom, by John Hanning Speke, the first European to discover this lake....
in Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. Like other spiders in the genus Myrmarachne
Myrmarachne
Myrmarachne is a genus of jumping spiders which imitate an ant by waving their front legs in the air to simulate antennae. Some species also look strikingly like ants....
, these 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 mimic
Batesian mimicry
Batesian mimicry is a form of mimicry typified by a situation where a harmless species has evolved to imitate the warning signals of a harmful species directed at a common predator...
ant
Ant
Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...
s, in this case, ants of the Crematogaster
Crematogaster
Crematogaster is an ecologically diverse genus of ants found worldwide, which are characterised by a distinctive heart-shaped gaster , which gives one of their common names, Valentine Ant. It is the only genus of the tribus Crematogastrini. Most of species are arboreal...
genus. However, they are unusual in that they exhibit some form of social behavior
Social animal
A social animal is a loosely defined term for an organism that is highly interactive with other members of its species to the point of having a recognizable and distinct society.All mammals are social to the extent that mothers and offspring bond...
, forming clusters of 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...
nests on fig
Ficus
Ficus is a genus of about 850 species of woody trees, shrubs, vines, epiphytes, and hemiepiphyte in the family Moraceae. Collectively known as fig trees or figs, they are native throughout the tropics with a few species extending into the semi-warm temperate zone. The Common Fig Ficus is a genus of...
and other trees. Hundreds of these spiders, of both sexes and of all ages, can be found in such communal nests, but most nests have between 10 and 50 spiders. The Crematogaster ants which they mimic are often found in the nests with the spiders, along with other species of jumping spider.
Some predators (including larger jumping spiders) eat jumping spiders but are averse to attacking ants, as ants aggressively defend themselves. M. melanotarsa takes advantage of this aversion by mimicking the ants. Spiders of the genera Menemerus
Menemerus
Menemerus is a spider genus of the Salticidae family .-Species:* Menemerus acuminatus Rainbow, 1912 — Queensland* Menemerus albocinctus Keyserling, 1890 — Nicobar Islands* Menemerus animatus O...
and Pseudicius
Pseudicius
Pseudicius is a spider genus of the Salticidae family .-Relationships:The small genus Wesolowskana should possibly be included in this genus. There is some dispute whether Afraflacilla is a distinct genus or should be included in Pseudicius...
have been shown to flee, leaving their eggs behind, when in the presence of groups of M. melanotarsa. M. melanotarsa is known to eat the eggs of such spiders. However, individuals or small groups of M. melanotarsa may be attacked and eaten by these predators who fear large groups.