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Mediterranean Black Widow (Latrodectus tredecimguttatus)

The Mediterranean black widow spider has a history that dates back to 1790 when Italian expert Pietro Rossi introduced us to it. These spiders belong to the comb-footed family. Interestingly, they were once thought to be a close relative of the southern black widow. Get ready to discover more fascinating details about them here!

Table Of Content hide

Physical Description and Identification

Are Mediterranean Black Widow Spiders Venomous?

Can Mediterranean Black Widow Spiders Bite?

Ecological Importance and Behavior of Mediterranean Black Widow

Quick Facts

Did You Know

Physical Description and Identification

Adults

Size: Male: 0.4-0.7 cm Female: 0.7-1.5 cm
Color: They are black, with thirteen spots on their dorsal abdomen. These spots are red but sometimes yellow or orange in some individuals.
Other Characteristic Features: Their abdomen is covered in long and short hairs.

Eggs

They lay their eggs in a giant white sac, producing 6-8 sacs in their lifetime.

Spiderlings

Hundreds of spiderlings emerge from the sac laid by their mother.

The Web

Their webs consist of three layers, with the middle layer shaped like a series of hexagonal meshes.

Are Mediterranean Black Widow Spiders Venomous?

Yes, Mediterranean Black Widow spiders are venomous and can pose a threat to humans with their bite. Only the females are considered deadly, as the males lack strong mouthparts to pierce human skin.

Can Mediterranean Black Widow Spiders Bite?

Absolutely! Mediterranean Black Widow spiders can and do bite, especially when they feel threatened or disturbed. Their bite is painful but only fatal in rare cases.

Ecological Importance and Behavior of Mediterranean Black Widow

The Mediterranean black widow spider is an important predator in its ecosystem, mainly consuming insects like ants and beetles. This diet helps control the population of these insects, contributing to ecological balance.

Natural Predator: Birds, wasps, and some small mammals are known to prey upon the Mediterranean black widow, which helps manage their numbers in the wild.

Prey-Predator Dynamics: This species is a pivotal part of the food chain, acting as both a predator to numerous insects and as prey to various larger species, ensuring the maintenance of natural cycles within their grassland habitats.

Relationship with Humans: While encounters with humans are relatively rare, there is an overlap between human agriculture and the spider’s natural territory, which can lead to bites. However, incidents of fatal bites are extremely rare and usually only occur under specific circumstances.

Quick Facts

Other names	European black widow, karakurt (“black worm”)
Lifespan	1-3 years
Distribution	Caucasus, Central Asia, China, Iran, Kazakhstan, Mediterranean, Russia (Europe to South Siberia), and Ukraine
Habitat	Steppes and other grasslands
Common Predators	Birds, wasps, some small mammals
Diet	Insects like ants and beetles

Did You Know

While generally not coming in contact with humans, there have been reports of farm workers being bitten, as their farmlands often overlap with the spider’s natural habitat.

In Kazakhstan, there have been reports of the bite of the Mediterranean black widow killing camels.

In conclusion, the Mediterranean black widow spider, with its venomous bite and distinctive appearance, plays a crucial role in the ecological systems of grasslands and steppes.

Frequently Asked Questions

What does a Mediterranean black widow look like?

A Mediterranean black widow is identified by its glossy black body and thirteen distinct spots on its dorsal abdomen. These spots are typically red but can also be yellow or orange. Females measure 0.7-1.5 cm, while the smaller males are only 0.4-0.7 cm long.

Are Mediterranean black widows dangerous to humans?

Yes, Mediterranean black widows are considered dangerous to humans due to their potent venom. The bite from a female can be medically significant, causing severe pain and other symptoms. While fatalities are rare, their bites require immediate medical attention to manage the effects of the neurotoxin.

Why do Mediterranean black widows bite people?

Mediterranean black widows typically bite people only in self-defense when they feel threatened or disturbed. A bite is a defensive reaction, often occurring when the spider is accidentally pressed against a person’s skin. They are not inherently aggressive and prefer to avoid contact with humans whenever possible.

What kind of insects do Mediterranean black widows eat?

The diet of a Mediterranean black widow primarily consists of various insects. They are important predators that help control local insect populations by consuming prey such as ants, beetles, and other small arthropods that get trapped in their complex, three-layered webs. This predation is vital for ecological balance.

How can you identify a Mediterranean black widow’s web?

You can identify a Mediterranean black widow’s web by its distinct three-layered structure. It is an irregular, tangled web, but the middle layer is uniquely constructed with a series of hexagonal meshes. This complex design is highly effective at trapping the ground-dwelling insects that the spider preys upon.

How many eggs does a Mediterranean black widow lay?

A female Mediterranean black widow lays her eggs inside a large, white, silken egg sac. Over her lifetime, she can produce between six and eight of these sacs. Each individual sac can contain hundreds of eggs, leading to the emergence of a large number of spiderlings upon hatching.

Is the male Mediterranean black widow venomous?

While the male Mediterranean black widow does possess venom, it is not considered a threat to humans. The male’s mouthparts, or chelicerae, are too small and weak to effectively pierce human skin and deliver a significant amount of venom. Only the larger female is medically dangerous.

Mediterranean Black Widow (Latrodectus tredecimguttatus)