The wandering or wandering spider, as well as the “runner spider”, in English-speaking countries “banana spider”, and in Brazil it is known as “aranha armadeira”, which means “armed spider” or soldier spider – all these are names deadly killer. Death from the bite of a spider soldier, if he injects a full dose of poison, will occur within an hour in 83% of cases.
Origin of the species and description
The genus Phoneutria was discovered by Maximilian Perty in 1833. The genus name comes from the Greek φονεύτρια, meaning “killer”. Perty combined the two species into a genus, P. rufibarbis and P. fera. The former is treated as a “doubtful representative”, the latter as a typical species of the genus. At the moment, the genus is represented by eight species of spiders that are found naturally only in Central and South America.
The Brazilian warrior spider entered the 2007 Guinness Book of Records as the most poisonous animal.
Members of this genus are among the most medically important spiders in the world. Their venom consists of a mixture of peptides and proteins that act together as a powerful neurotoxin in mammals. From a pharmacological point of view, their venom has been carefully studied, and its components can be used in medicine and agriculture.
Video: Soldier Spider
It has been observed that bites were accompanied by prolonged and painful erection in representatives of the strong half of humanity. The reason is that the venom of the soldier spider contains the Th2-6 toxin, which acts on the mammalian body as a powerful aphrodisiac.
Experiments have confirmed the supposed version of scientists that this toxin can become the basis of a drug that is likely to be able to treat erectile dysfunction in men. Perhaps in the future, the militant spider soldier will be able to get into the Book of Records again for his participation in the development of impotence remedy.
Appearance and features
To Phoneutria view (soldier spiders) are large and robust members of the Ctenidae (runners) family. The body length of these spiders ranges from 17-48 mm, and the leg span can reach 180 mm. Moreover, females are 3-5 cm long with a leg span of 13-18 cm, while males have a smaller body size, about 3-4 cm and a leg span of 14 cm.
The general color of the body and legs varies by location, but the most common is light brown, brown or gray with small lighter dots with a dark outline, which are located in pairs on the abdomen. Some species have two longitudinal lines of lightly colored spots. Within a species, the coloration of the abdomen is an inaccurate feature for differentiating the species.
Curious fact! Experts believe that some species of spiders may “dry” bite” to retain their venom, unlike more primitive varieties that inject the full dose.
The body and legs of the soldier spider are covered short brown or grayish hairs. Many species (P. boliviensis, P. fera, P. keyserlingi, and P. nigriventer) have bright rufous hairs on their chelicerae (structures on the face, just above the fangs), and visible stripes of black and yellow or white on the undersides of the two front pairs of legs.
The genus differs from other related genera, such as Ctenus, by the presence of dense proliferative clumps (thick brush of fine hairs) on the tibiae and tarsi in both sexes. Soldier spider species resemble those of the genus Cupiennius Simon. Like Phoneutria, Cupiennius is a member of the Ctenidae family but is largely harmless to humans. Since both genera are often found in food or cargo shipments outside their natural range, it is important to distinguish between them.
Where does the soldier spider live?
Soldier spider – found in the tropics of the Western Hemisphere, which occupy most of the northern part of South America north of the Andes. And one species, (P. boliviensis), also spreads to Central America. There are data on spider soldier species in: Brazil, Ecuador, Peru, Colombia, Suriname, Guyana, northern Argentina, Uruguay, Paraguay, Bolivia, Mexico, Panama, Guatemala and Costa Rica. Within the genus, P. boliviensis is the most common, with a geographic range from Central America south to Argentina.
The species Phoneutria bahiensis has the most limited geographic distribution and is found only in the Atlantic forests of the Brazilian states of Bahia and Espírito Santo. For this species, only Brazil is considered a habitat.
If we consider the range of the animal for each species separately, they are distributed as follows:
- P.bahiensis is endemic for a small area in the state of Bahia in Brazil;
- P.boliviensis is found in Bolivia, Paraguay, Colombia, northwestern Brazil, Ecuador, Peru and Central America;
- P.eickstedtae oocurs in several locations along the rainforest in Brazil;
- P.fera is found in the Amazon, Ecuador, Peru, Suriname, Brazil, Guyana;
- P.keyserlingi is found in the Atlantic tropical coast of Brazil;
- P.nigriventer is found in the northern Argentina, Uruguay, Paraguay, Central and Southeast Brazil. Several samples found in Montevideo, Uruguay, Buenos Aires. They were probably introduced with fruit shipments;
- P.pertyi is found in the Atlantic tropical coast of Brazil;
- P.reidyi is found in the Amazonian region of Brazil, Peru, Venezuela, and Guyana.
In Brazil, the soldier spider is only absent from the northeastern region north of Salvador, Bahia.
What does the soldier spider eat?
Spider soldiers are nocturnal hunters. During the day, they seek shelter in vegetation, tree crevices, or inside termite mounds. With the onset of darkness, they begin to actively search for prey. The spider soldier defeats potential prey with powerful venom rather than relying on webs. In most spiders, venom serves as a method of subduing prey. The attack occurs both from an ambush and with a direct attack.
Adult Brazilian wandering spiders feed on:
- small lizards;
- non-flying fruit flies;
- other spiders;
- large insects.
P.boliviensis sometimes wraps captured prey in a web, attaching it to the substrate. Some species often hide in large-leaved plants such as palms as ambush sites before hunting.
Also, immature teenage spiders like to hide in such places, avoiding the attack of larger spiders, which are potential predators on the ground. This provides them with the ability to better sense the vibrations of an approaching predator.
Most attacks on humans occur in Brazil (~4000 cases per year) and only 0.5% are severe. Local pain is the main symptom reported after most bites. Treatment is symptomatic, with antivenom only recommended for patients who develop important systemic clinical manifestations.
Symptoms occur in ~3% of cases and affect mainly children under 10 years of age and adults over 70 years of age. Fifteen deaths attributed to the spider soldier have been recorded in Brazil since 1903, but only two of these cases are sufficient evidence to confirm the connection with the bite of Phoneutria. lifestyle
The wandering soldier spider got its name because it moves on the ground in the jungle, and does not live in a lair or on a web. The roaming nature of these spiders is another reason why they are considered dangerous. In densely populated areas, Phoneutria species typically seek cover and dark places to hide during the daytime, leading them to hide in houses, clothing, cars, boots, crates, and piles of logs, where they can bite if they are accidentally disturbed.
The Brazilian soldier spider is often referred to as the “banana spider” because it is sometimes found in banana shipments. Therefore, any large spider that appears on bananas should be treated with due care. The people who unload them should be well aware of the fact that bananas are a common hiding place for this highly venomous and dangerous type of spider.
Unlike most other species that use webs to catch insects , soldier spiders use the web to more easily move through trees, form smooth walls in burrows, create egg bags, wrap already caught prey.
Brazilian spider soldiers — one of the most aggressive spider species. They will fight each other for territory if there are too many of them in one place. Males are also known to become very belligerent towards each other during the mating season.
They want every chance to successfully mate with their chosen female, so they can harm their congener. Spider soldiers usually live two — three years. They do not do well in captivity due to the stress they receive. They may even stop eating and become completely lethargic.
Social Structure and Reproduction
In almost all species of spiders, the female is larger than the male. This dimorphism is also present in the Brazilian warrior spider. Male soldiers roam in search of females between March and May, which corresponds to the time when most cases of infection of people from bites occur.
Males approach the female very cautiously when trying to mate. They perform a dance to get her attention and fight fiercely against the other challengers. The “fair sex” is very picky, and will often turn down many males before choosing one to mate with.
Male spiders must timely retreat away from the female after mating in order to have time to escape before the normal predatory instincts of the mate return.
Runners breed — soldiers with the help of eggs, which are packed in bags of cobwebs. Once the sperm is inside the female, she stores it in a special chamber and uses it only during oviposition. Then the eggs first come into contact with male sperm and are fertilized. The female can lay up to 3,000 eggs in four egg sacs. Spiderlings appear after 18-24 days.
Immature spiderlings can capture prey as soon as they emerge from the egg sac. As they grow, they must shed and shed their exoskeleton to ensure their continued growth. In their first year, spiderlings are exposed to 5 — 10 molts, depending on temperature and amount of food consumed. As you get older, the frequency of moulting decreases.
In their second year of life, growing spiders molt three to six times. During the third year, they molt only two or three times. After one of these molts, the spiders usually become sexually mature. As they mature, the proteins present in their venom change, becoming more deadly to vertebrates.
Soldier’s spider’s natural enemies
Brazilian spider soldiers — ferocious predators and they have few enemies. One of the most dangerous — wasp tarantula hawk, which belongs to the genus Pepsis. This is the largest wasp in the world. It is not usually aggressive and does not usually attack other species other than spiders.
Female wasps seek out their prey and sting them, temporarily paralyzing them. Then the wasp lays an egg in the abdominal cavity of the soldier spider and drags it into a pre-prepared hole. The spider does not die from poison, but from a hatched baby wasp eating the spider’s abdomen.
When confronted with a potential predator, all members of the genus demonstrate a threat. This characteristic defensive posture with the front legs raised is a particularly good indicator that the specimen is Phoneutria.
Spider soldiers are more likely to hold their ground than retreat. The spider stands on two hind pairs of legs, the body is almost perpendicular to the ground. The two pairs of forelegs are raised up and held above the body, showing the brightly colored lower legs. The spider swings its legs sideways and shifts towards the movement of the threat, showing fangs.
There are other animals that can kill the soldier spider, but usually this is due to death in a random fight between the spider and large rodents or birds. In addition, people destroy members of the genus as soon as they are discovered, trying to prevent the bites of the soldier spider.
Due to the toxicity of their bite and their tense appearance, these spiders have a reputation for being aggressive. But this behavior of — protective mechanism. Their menacing stance serves as a warning to predators that a venomous spider is ready to attack.
Soldier spider bites — means of self-defense and are done only if they are provoked intentionally or accidentally. In the soldier spider, the venom has gradually evolved, performing a protective function against mammals.
Population and species status
The stray soldier spider has been named the most venomous spider in the world by Guinness World Records for several years now, although as aranologist Jo-Anne Nina Seulal has pointed out, “It is debatable to classify an animal as deadly, since the amount of harm done depends on the amount of poison injected.”
Populations of the genus Phoneutria are currently not threatened, although soldier spiders have a small distribution area. Basically, wandering spiders travel through the jungle where they have few enemies. The only species of concern is Phoneutria bahiensis. Due to its narrow distribution range, it is listed as a potentially endangered species on the Red List of the Brazilian Ministry of the Environment.
Brazilian soldier spiders are certainly dangerous and bite more people than any other spider species. People bitten by this spider or any of the Ctenid species should seek emergency care immediately as the venom may be life threatening.
Phoneutria fera and Phoneutria nigriventer are two of the most vicious and deadly of the Phoneutria spiders. Not only do they have a powerful neurotoxin, but they also cause one of the most excruciating post-bitten pain conditions of any spider due to their high concentrations of serotonin. They have the most potent venom of any spider on the planet.
Phoneutria’s venom contains a powerful neurotoxin known as PhTx3. It acts as a broad spectrum calcium channel blocker. In lethal concentrations, this neurotoxin causes loss of muscle control and breathing problems, leading to paralysis and possible suffocation.
Specialists were called to a London home to capture a soldier’s spider after residents bought in the supermarket a bunch of bananas. In an attempt to escape, a Brazilian spider soldier ripped off his leg and left behind an egg sac full of thousands of small spiders. The family was in shock and could not even spend the night in their house.
In addition, the spider soldier produces such a poison that causes severe pain and inflammation after being bitten due to the stimulating effect it has on serotonin 5-HT4 receptors in sensory nerves. And the average lethal dose of poison is 134 mcg/kg.