The black widow spider (Latrodectus spp.) is a spider notorious for its neurotoxic venom. It is a large widow spider found throughout the world and commonly associated with urban habitats or agricultural areas. Although the common name ‘black widow spider’ is most commonly used to refer to the three North American species best known for their dark coloration and red hourglass pattern, it is occasionally also applied to several other members of the Latrodectus (widow spider) genus in which there are 31 recognized species including the Australian red-back, brown widow spider (sometimes called the gray widow), and the red widow spider.
In South Africa, widow spiders are also known as the button spiders. Currently, there are three recognized species of black widow found in North America: The southern black widow (L. mactans), the northern black widow (L. variolus), and the western black widow (L. hesperus).

Southern Black Widow (L. mactans)

The southern black widow, L. mactans , is found in Pennsylvania. It is probable that the northern black widow, L. variolus , is also present. Occasionally, the brown and the red widow spiders are introduced on potted plants from southern Florida. The female southern black widow is normally a shiny, jet-black spider 8 to 13 millimeters in body length. With legs extended, the female measures about 25 to 35 millimeters long. The male, which is black and has white underbody markings with red spots, is only 4 to 6 millimeters long (12 to 18 millimeters including its legs). The female has the well-known reddish hourglass marking on the underside of her abdomen. The bite of female black widows is, at first, relatively painless. Pain will be felt about one to two hours later, and occasionally the patient may experience a tingling along the nerve routes or down the spine. There is almost no swelling at the site of the bite. However, the site will typically exhibit two red fang marks and may be surrounded by a rash or erythema. Black widow venom is principally neurotoxic. Generalized body symptoms, which develop within one to three hours, may include any of the following: nausea, chills, slight fever, rise in blood pressure, retention of urine, burning sensation of the skin, fatigue, motor disturbances, breathing difficulty, constipation, and muscle aches, particularly in the abdomen. These symptoms usually disappear after four days. Death does not normally occur, except in the elderly or very young. Treatment typically includes the use of calcium gluconate (to reduce muscle cramps), Latrodectus antivenom, and diphenhydramine hypochloride to counteract allergic reactions to the antivenom. Additional treatments include antispasmatic medications and analgesics.

Northern Black Widow (L. variolus)

With the days and nights getting cooler there isnt much time left to be in the field. This is my favorite time of year to look for Latrodectus variolus. These are more elusive than L mactans mostly because of its habitat. While L mactans seems to prefer more open areas that are rocky and even close to human dwellings, L variolus prefers heavily forested areas which are located on ridges and hillsides. Juveniles and males have nice colors. This is an adult male. Finding the webs can be difficult, however if you walk with the Sun in front of you they will glow when sunlight hits them. The webs are typical of other Latrodectus in that they are tangled and the silk is very strong. L variolus seems to prefer to make their webs among the leaf litter on the ground. Often they make their retreat next to a small bush, in this case a Wild Huckleberry.

Western Black Widow (L. hesperus)

Outdoors, western black widow spiders may be terrestrial or live above the ground. Indoors, they build their webs in undisturbed areas that are not frequented by humans. In arid parts of Arizona, this spider inhabits almost every crevice in the soil and its nests are found in cholla cacti and agave plants. The western black widow female’s body is about half an inch long. Females have a complete hourglass marking on the underside of the abdomen, which is usually completely black except for a small reddish spot near the tip. As female western black widows grow older, they gradually develop into a shiny black or dark brown, with a bright red or orange hourglass. The male is less than half the size of the female. Males of the western black widow have three diagonal pale stripes on each side of the abdomen and are usually light brown, whereas males of the other species of Latrodectus are generally black. Mature male western black widows do not drastically change their body coloration and resemble juveniles of both sexes. Yet, like the female, the male’s hourglass becomes brighter in color, usually yellow or orange.

Goliath tiger fish, such as the one seen above, are among the uniquely adapted “monster fish” of the Congo River, which winds through several African countries A recent, unprecedented river run on the Congo yielded a raft of new discoveries, including different species–some potentially new–in nearly every nook and cranny, scientists announced this week.

The river was also found to be possibly the world’s deepest, and its extraordinary changes in depths and currents help explain why it’s such a hotbed of fish diversity.

“What we’re seeing here is kind of evolution on steroids,” said team leader Melanie Stiassny, a fish biologist at the American Museum of Natural History. Stiassny, a member of the National Geographic Society’s Conservation Trust, was among the marine and evolutionary biologists, hydrologists, and kayakers who conducted the exhaustive research in summer 2008. — nationalgeographic.com

The Chain Moray Eel, also known as the Chainlink Moray Eel, or simply, the Chain Eel, has a white to yellow body with handsome brown, black, or gray chain markings.

It needs refuge among or in between coral and rocks in a 125 gallon or larger aquarium. It spends most of its day hiding and moves about at night in search of food.

The Chain Moray Eel requires 2 or 3 live meals (grass shrimp, fiddler crabs) per week. If it does not eat at first, try impaling some food, such as live or frozen fish, krill, shrimp, or crustacean flesh, on a feeder stick.

Family: Muraenidae
Range: Western Atlantic
Size: Up to 28 inches
Diet: Carnivore
Tank Set-up: Marine: Coral or rock, plants
Reef Compatible: No
Tank Conditions: 72-78ºF; sg 1.020-1.025; pH 8.1-8.4
Minimum Tank Capacity: 125 gallon
Light: Low
Temperament: Semi-aggressive
Swimming Level: Bottom
Care Level: Easy
Reproduction: Egg Layer — www.peteducation.com

Latrodectus rhodesiensis was originally described from Zimbabwe. They are usually paler in colour and their egg sacs are distinct in being larger and having a more fluffy appearance. They have been recorded from Zimbabwe and also small areas in Gauteng, Mpumalanga and the Limpopo Province.

Symptoms of Latrodectism: only the female button spider is able to pierce the skin in humans, and in most cases the potential full dosage of venom is not administered. The term latrodectism is used to describe the symptoms and signs caused by envenomation of the button spiders. The black button complex causes a more severe form of envenomation than the brown button spiders. — www.scienceinafrica.co.za

Size

Female: about 12-16 mm (> 0.5 inch) long (body length only, not including legs)
Male: much smaller, 6-8 mm (about half the body length of a female) but with longer legs.

Identification

The brown widow is highly variable in color. It may be almost white to almost black. Typically, it is a light to medium brown, with an orange-to-yellow hourglass marking on the underside of the abdomen; the coloration of the hourglass often is a good indication of this species. The leg segments are banded, with one half of each segment lighter in color than the other half. The back often has a row of white spots (rarely orange or light blue), and there are a few white stripes on each side. Darker individuals lack these markings and are difficult to distinguish from black widows.

If an eggsac is present, this is the best identifying characteristic. Brown widow eggsacs are tan, spherical, and have many small tufts of silk sticking out from them. They resemble a ’sandspur.’ The other widows make white, smooth eggsacs that tend to be pear-shaped.

Range

World wide in the tropical zone. It was introduced in Florida and has since been observed moving north through Georgia, and into South Carolina; it has also been officially recorded in California, Alabama, Mississippi, and Texas.

Habitat

Found around buildings in tropical climates. However, it is an introduced species and is the most human-adapted of the species occurring in the South Eastern US. Its webs may occur anywhere there is sufficient space to make one. It may be extremely abundant on houses and other man-made structures (e.g., barns, fences, guard rails, bridges). It reproduces frequently and disperses rapidly, making it nearly impossible to control.

Food

Typically insects, but has been observed killing small toads that have gotten caught in its web (but no confirmed record of eating the toad).

Life Cycle

Females can live up to 3 years, while the males only live from 6 months to 1 year. The Brown Widow is the most actively reproducing widow species, producing up to 5000 young per female per season.

Remarks

Widow Bites:

NOTE: It is recognized that this particular species of widow is most likely not medically significant (not an immediate medical concern to those who are bitten). (Net Ref (4)) The brown widow produces clinical effects similar to that of the black widow but the typical symptoms and signs being milder and tending to be restricted to the bite site and surrounding tissues. (Print Ref 1)

Brown widow spiders usually curl up into a ball, and drop to the ground as a primary defense. It is highly recommended that people leave this spider alone; observe, but don’t touch.

Males and immatures do not bite. The brown widow is an extremely timid spider which has rarely been reported to bite.

Precautions:

Be very careful when working around areas where widow spiders may be established. Take proper precautions-wear gloves and pay attention to where you are working. The reaction to a widow bite can be painful, and the victim should go to the doctor immediately for treatment.

The first record of the African black widow spider, Latrodectus cinctus Blackwall, 1865 (= L. indistinctus Pickard-Cambridge, 1904) from Liberia is presented.

It is a further record of a savanna species in the forest zone of West Africa. Increasing deforestation may cause expansion of the ranges of savanna-inhabiting animal species into the forest zone. — www.researchgate.net

They are nocturnal, web-living spiders. Button spiders are very timid, usually retreating when disturbed or dropping to the ground and playing dead.

Bites usually result from handling or when they are trapped and squeezed. — www.savp.co.za

The yellow garden spider, also known as Argiope aurantia is most abundant from the end of July to mid September. They produce huge orb webs and hangs in their webs with their head down waiting for prey.

The prey they feed on are small insects and the only insects they got are the ones trapped in their web. These spiders are sometime called writing spiders due to the zig-zag patterns often found in their webs. The patterns are called stabilimenta since they add stability to the web.

This picture is a close-up of a yellow garden spider eating a cicade.

The yellow garden spider is not dangerous to healthy people, since the only symptoms from a bites is an itchy swelling that’s over in 2 or 3 days. — venomous-spiders.nanders.dk

The wolf spiders belong to the Lycosidae family and consists of several species. The one described here is the Lycosidae godeffroyi. This wolf spider is typically found in suburban areas of Australia and is commonly known as the garden wolf spider.

An effective wandering spider

The godeffroyi wolf spider is a wanderer and from time to time it build small burrows - else it resides in the open vegetation. It’s a very robust and agile spider. It is able to hunt in the open and it locates its prey by sight. Eyes of all wolf spiders are arranged in three rows and this makes up the first line of identification when looking at a spider suspected to be a wolf spider.

For healthy people a bite from a wolf spider isn’t deadly. A bite causes local itching and in rare cases swelling and dizziness. For security reasons it is the best to seek medical treatment following a bite from Wolf Spider.

It’s not only the venom that matters - a bite from a spider is often followed by a bacterial infection which can be more dangerous than the bite itself. — venomous-spiders.nanders.dk

Introduction

The yellow sack spider with the Latin name Cheiracanthium inclusum is very common in most of the United States. The yellow sack spider is a cause of many bites in the US and a lot of house spiders are crushed on suspicion of being yellow sac spiders. Its bite corresponds to a bite from a wasp.

Bites from yellow sac spider are also often misidentified as brown recluse spider bites. The symptoms and the development of the wound are quite the same but much less severe.

Life cycle of the yellow sac spider

In the autumn the food is disappearing and the yellow sac spider seeks indoor to find food. Indoors it is often seen on walls and around different constructions. If disturbed it drops to the floor. Egg sacs are laid in corners of all sorts. The egg sacs are white and spunk with silk. The female may guard its egg sac one way of the other so one has to be careful removing egg sacs from a yellow sac spider.

During the summer when there’s plenty of food the yellow sack spider prefers to live on trees, shrubs, and in low vegetation close to open expanses, such as fields. Occasionally it is found in cotton crops.

The yellow sac spider over winters as spiderlings (juveniles) and molt to the adult stage during spring. Females of the yellow sac spider covers her loosely distributed eggs with thin white silk. Adults can be found from April through November, but in the hottest month’s small spiders makes up the largest proportion of the population.

How and when yellow sac spiders searches for prey

Yellow sac spiders are active in the night, where they wander around to find prey. The prey is a wide diet of arthropods, including spiders larger than themselves and even their own eggs.

The spider does not produce webs. Instead they construct sacs in protected areas. The idea of creating sacs instead of webs has given the Yellow Sac Spider its name.

Around 30 percent of adult males get killed and consumed by females at mating. A female produces around 5 egg sacs each with around 37 eggs. They eggs are laid in a loose mass and covered with a thin coat of spun silk.

The strength of the fangs of a yellow sac spider

The chelicerae of yellow silk spiders are very powerful, and the fangs can penetrate human skin quite easily. Most bites on humans occur when people are gardening or performing other kinds of outdoor activities. The venom has mild and local cytotoxic and neurotoxic effects. No fatal incidents from encounters with the yellow sac spider have ever been recorded.

However the bite is quite painful from the outset. A person usually develops redness, swelling, and itching near the site of the bite. Redness disappears after about 72 hours and the skin heals in a week or two.

Sac spiders are the probable cause of more spider bites than any other kind of spider, and their bites are probably often misdiagnosed as brown recluse bites by health care providers.

Preventing spider bites

If you want to prevent you and your family from yellow sac spider bites you can take certain measures. First of all you can shake your clothes before getting dressed. Also you can wear pre inspected clothes when doing garden work or handling firewood etc. Also, by removing your bed from the wall you can minimize the risk of close encounters with the yellow sac spider while asleep.

To protect your house from yellow sac spiders you can install tight fitting screens on windows and doors. You can also seal any crack or crevice a spider can fit into or get access to your house through. Installing yellow light on your front and back porch might also attract fewer insects, which are food for most if not all spiders.

If you want to go further you can remove any kind of debris near the foundation of your house. You can make a tight cleaning schedule in your house or apartment to get rid of insects etc. that will attract spiders (which by the way are not insects) because insects are prey. — venomous-spiders.nanders.dk