Home / Sicariidae Spiders / Brown Recluse Spider (Loxosceles reclusa)

Brown Recluse Spider (Loxosceles reclusa)

The brown recluse spider is a special spider found mostly in the central and southern parts of the U.S. It’s part of a small group of spiders in North America known for having strong venom, along with the Chilean recluse and black widow. In this post, we’re going to share cool facts about the brown recluse spider.

Scientific Classification

Brown Recluse Spider

Photo Credit: J.C. Chang

Physical Description & Identification

Adult

  • Size: They are 6-20 mm (0.24 -0.79 inches) in size, though they can be larger.
  • Color: As its name suggests, it has a light brown body with blackish-gray, whitish, or dark brown tinges. Its cephalothorax, on the other hand, may be yellowish-brown or light brown.
  • Other characteristics: The dorsal section of the brown recluse’s cephalothorax contains markings and a black line, forming a violin-like pattern lying pointed towards the abdomen.  Unlike most other spiders, the brown recluse has six eyes (one medial, two lateral pairs).

Eggs

The silken egg sacs, off-white in color with a diameter of 1/3 inch contain about 50 eggs on average.

Spiderlings

The spiderlings of this species come out of the egg case in about 36 days, taking a year to mature. The immature ones look similar to the adults though they have light brown bodies. Moreover, by the time they are juveniles, these species attain mobility and can travel for long distances. Even the spiderlings can inject venom that could cause serious reactions in mankind.

Baby Brown Recluse

Photo Credit: feathersong1

The Web

Their webs are irregular and loosely constructed mostly found in dark, dingy areas. However, being hunting spiders, they generally do not take the help of their web to capture prey.

Are Brown Recluse Spiders Venomous?

Yes, Brown Recluse spiders have strong venom. They use it to catch their bug meals. It’s one reason people talk about them a lot.

Can Brown Recluse Spiders Bite?

Yes, Brown Recluse spiders can bite. They’re usually quiet, but they might bite if they feel scared or if they’re accidentally touched.

What are the Symptoms of a Brown Recluse Spider Bite?

The symptoms could be mild to severe, depending on the intensity of the bite. In the majority of cases, the pain and itchiness are experienced between 2 and 8 hours after being bitten and in the case of extremities, the situation may worsen within a day or two.

Common symptoms include redness, itching, and pain in the area of the bite, alongside a deep sore. Fever, weakness, chills, nausea, and joint pains could even occur and in rare cases, there may be seizures, and under severe circumstances, the person may even go into a coma.

Treatment

The treatment depends on the extremities of the symptoms and may vary from one person to the other. Some common treatments undertaken by medical personnel include pain medication, tetanus immunization, antibiotics, and even antihistamines.

Ecological Importance and Behavior of Brown Recluse Spider

The Brown Recluse spider, scientifically known as Loxosceles reclusa, plays a vital role in controlling pest populations, contributing to the ecological balance of its native habitats.

Natural Predator: The Brown Recluse spider has several natural enemies, which help in controlling its population. These include Centipedes, Wolf spiders, Some species of ants, Scorpion spiders, and Birds.

Prey-Predator Dynamics: Brown Recluse spiders primarily prey on insects, especially cockroaches, crickets, and other pests. They use an ambush technique to surprise their prey, relying on their venom to immobilize and then consume their catch. 

Relationship with Humans: The Brown Recluse is infamous for its venomous bite, which can cause severe reactions in humans, including necrosis of the skin. While they are not naturally aggressive and bite only when threatened or provoked, their preference for dark, quiet spaces in homes can lead to unintentional encounters with humans. 

Quick Facts  

Lifespan1 to 2 years
DistributionThe south-central and Midwestern parts of the United States including areas of southeastern Nebraska, Illinois, Ohio, Indiana, western Georgia, and northern parts of Kentucky
HabitatDry, dark, and dingy areas, alongside nesting places that are undisturbed like sheds, woodpiles, garages, and closets
Common Predators Birds, cats wasps, and other spider species like cat-faced, wolf, and crab
Diet Soft-bodied insects like cockroaches, flies, crickets, and moths

Did You Know

  • The violin pattern on their body has earned them the nicknames violin, fiddle back, and brown fiddler.
  • Another spider of notorious reputation is the hobo spider which is also reddish-brown but different from the brown recluse in appearance, as the former has a distinct pattern on its abdomen not present in the latter.

The brown recluse spider is a special spider found mostly in the central and southern parts of the U.S. It’s part of a small group of spiders in North America known for having strong venom, along with the Chilean recluse and black widow. In this post, we’re going to share cool facts about the brown recluse spider.

Brown Recluse Spider

Photo Credit: J.C. Chang

Physical Description & Identification

Adult

  • Size: They are 6-20 mm (0.24 -0.79 inches) in size, though they can be larger.
  • Color: As its name suggests, it has a light brown body with blackish-gray, whitish, or dark brown tinges. Its cephalothorax, on the other hand, may be yellowish-brown or light brown.
  • Other characteristics: The dorsal section of the brown recluse’s cephalothorax contains markings and a black line, forming a violin-like pattern lying pointed towards the abdomen.  Unlike most other spiders, the brown recluse has six eyes (one medial, two lateral pairs).

Eggs

The silken egg sacs, off-white in color with a diameter of 1/3 inch contain about 50 eggs on average.

Spiderlings

The spiderlings of this species come out of the egg case in about 36 days, taking a year to mature. The immature ones look similar to the adults though they have light brown bodies. Moreover, by the time they are juveniles, these species attain mobility and can travel for long distances. Even the spiderlings can inject venom that could cause serious reactions in mankind.

Baby Brown Recluse

Photo Credit: feathersong1

The Web

Their webs are irregular and loosely constructed mostly found in dark, dingy areas. However, being hunting spiders, they generally do not take the help of their web to capture prey.

Are Brown Recluse Spiders Venomous?

Yes, Brown Recluse spiders have strong venom. They use it to catch their bug meals. It’s one reason people talk about them a lot.

Can Brown Recluse Spiders Bite?

Yes, Brown Recluse spiders can bite. They’re usually quiet, but they might bite if they feel scared or if they’re accidentally touched.

What are the Symptoms of a Brown Recluse Spider Bite?

The symptoms could be mild to severe, depending on the intensity of the bite. In the majority of cases, the pain and itchiness are experienced between 2 and 8 hours after being bitten and in the case of extremities, the situation may worsen within a day or two.

Common symptoms include redness, itching, and pain in the area of the bite, alongside a deep sore. Fever, weakness, chills, nausea, and joint pains could even occur and in rare cases, there may be seizures, and under severe circumstances, the person may even go into a coma.

Treatment

The treatment depends on the extremities of the symptoms and may vary from one person to the other. Some common treatments undertaken by medical personnel include pain medication, tetanus immunization, antibiotics, and even antihistamines.

Ecological Importance and Behavior of Brown Recluse Spider

The Brown Recluse spider, scientifically known as Loxosceles reclusa, plays a vital role in controlling pest populations, contributing to the ecological balance of its native habitats.

Natural Predator: The Brown Recluse spider has several natural enemies, which help in controlling its population. These include Centipedes, Wolf spiders, Some species of ants, Scorpion spiders, and Birds.

Prey-Predator Dynamics: Brown Recluse spiders primarily prey on insects, especially cockroaches, crickets, and other pests. They use an ambush technique to surprise their prey, relying on their venom to immobilize and then consume their catch. 

Relationship with Humans: The Brown Recluse is infamous for its venomous bite, which can cause severe reactions in humans, including necrosis of the skin. While they are not naturally aggressive and bite only when threatened or provoked, their preference for dark, quiet spaces in homes can lead to unintentional encounters with humans. 

Quick Facts  

Lifespan1 to 2 years
DistributionThe south-central and Midwestern parts of the United States including areas of southeastern Nebraska, Illinois, Ohio, Indiana, western Georgia, and northern parts of Kentucky
HabitatDry, dark, and dingy areas, alongside nesting places that are undisturbed like sheds, woodpiles, garages, and closets
Common Predators Birds, cats wasps, and other spider species like cat-faced, wolf, and crab
Diet Soft-bodied insects like cockroaches, flies, crickets, and moths

Did You Know

  • The violin pattern on their body has earned them the nicknames violin, fiddle back, and brown fiddler.
  • Another spider of notorious reputation is the hobo spider which is also reddish-brown but different from the brown recluse in appearance, as the former has a distinct pattern on its abdomen not present in the latter.