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Grass (Agelenopsis)

The American grass spider, as they are commonly called, is a genus of spiders belonging to the funnel weaver family, mostly indigenous to different parts of the United States.

Grass Spider

Scientific Classification

List of Species Belonging to the Genus

Agelenopsis actuosa Agelenopsis aleenae Agelenopsis aperta
Agelenopsis emertoni Agelenopsis kastoni Agelenopsis longistyla
Agelenopsis naevia Agelenopsis oklahoma Agelenopsis oregonensis
Agelenopsis pennsylvanica Agelenopsis potteri Agelenopsis riechertae
Agelenopsis spatula Agelenopsis utahana  

Physical Description & Identification

Adults

Size: They are moderately big in size, having a body length of about 0.74 inches (19 mm), with the males being smaller in size than the females.

Color: They are mostly brown in color while some species may also be seen in shades of gray, ivory, beige, black or a blend of various shades.

Other characteristics: They have eight eyes arranged in rows of three, two on top, four in the middle and two at the bottom. These species have two prominent spinnerets at the back, indistinct bands on the legs as well as two dark bands on each side of its cephalothorax.

Grass Spider Size

Eggs                  

The eggs are big and round, lying within a disc-shaped sac.

Grass Spider Egg

Spiderlings

The spiderlings of this species go through a lot of molts after emerging from the egg sac until it reaches adulthood.

The Web

The funnel spider spin sheet webs having a funnel shelter on one of the edges. Their webs are non-sticky, lacking the adhesive capacity, however, the grass spiders make up for this flaw by running fast while getting after their prey.

Are the Funnel Web Grass Spiders Venomous

The funnel web grass spiders are not harmful and rarely bite unless provoked or agitated. Moreover, their bite does not cause harm to mankind apart from the basic symptoms of swelling and redness. A species of this genus, the desert grass spider (Agelenopsis aperta) is said to produce agatoxins and their bite could be threatening for insects, though in mankind they are not of much medical significance.

Male Grass Spider

Quick Facts

Lifespan 1-2 years
Distribution Parts of the United States and Canada
Habitat Mostly outdoors amidst tall grasses, and the shrubby areas
Common Predators Lizards, chameleons, and geckos
Diet Small insects and other spiders
Picture of a Grass Spider

Did You Know

  • C. G. Giebel described these spiders for the first time in 1869.
  • Their genus name is a blend of Agelena and opsis, with the former being referred to the Eurasian grass spiders and the latter a Greek word, meaning to have a similar look.
  • The grass spider is often confused with the wolf spiders as both of them have similar color patterns around their head region, though the latter is more harmful than the former.
  • Because of their brown body, this species may even be mistaken for the venomous brown recluse, though the former can be mostly distinguished by the dark stripes running through its abdomen.
Funnel Web Grass Spider

Image Credits: Nature.mdc.mo.gov, I.pinimg.com, Upload.wikimedia.org, Extension.usu.edu, Objects.liquidweb.services, Suttonmass.org

The American grass spider, as they are commonly called, is a genus of spiders belonging to the funnel weaver family, mostly indigenous to different parts of the United States.

Grass Spider

List of Species Belonging to the Genus

Agelenopsis actuosa Agelenopsis aleenae Agelenopsis aperta
Agelenopsis emertoni Agelenopsis kastoni Agelenopsis longistyla
Agelenopsis naevia Agelenopsis oklahoma Agelenopsis oregonensis
Agelenopsis pennsylvanica Agelenopsis potteri Agelenopsis riechertae
Agelenopsis spatula Agelenopsis utahana  

Physical Description & Identification

Adults

Size: They are moderately big in size, having a body length of about 0.74 inches (19 mm), with the males being smaller in size than the females.

Color: They are mostly brown in color while some species may also be seen in shades of gray, ivory, beige, black or a blend of various shades.

Other characteristics: They have eight eyes arranged in rows of three, two on top, four in the middle and two at the bottom. These species have two prominent spinnerets at the back, indistinct bands on the legs as well as two dark bands on each side of its cephalothorax.

Grass Spider Size

Eggs                  

The eggs are big and round, lying within a disc-shaped sac.

Grass Spider Egg

Spiderlings

The spiderlings of this species go through a lot of molts after emerging from the egg sac until it reaches adulthood.

The Web

The funnel spider spin sheet webs having a funnel shelter on one of the edges. Their webs are non-sticky, lacking the adhesive capacity, however, the grass spiders make up for this flaw by running fast while getting after their prey.

Are the Funnel Web Grass Spiders Venomous

The funnel web grass spiders are not harmful and rarely bite unless provoked or agitated. Moreover, their bite does not cause harm to mankind apart from the basic symptoms of swelling and redness. A species of this genus, the desert grass spider (Agelenopsis aperta) is said to produce agatoxins and their bite could be threatening for insects, though in mankind they are not of much medical significance.

Male Grass Spider

Quick Facts

Lifespan 1-2 years
Distribution Parts of the United States and Canada
Habitat Mostly outdoors amidst tall grasses, and the shrubby areas
Common Predators Lizards, chameleons, and geckos
Diet Small insects and other spiders
Picture of a Grass Spider

Did You Know

  • C. G. Giebel described these spiders for the first time in 1869.
  • Their genus name is a blend of Agelena and opsis, with the former being referred to the Eurasian grass spiders and the latter a Greek word, meaning to have a similar look.
  • The grass spider is often confused with the wolf spiders as both of them have similar color patterns around their head region, though the latter is more harmful than the former.
  • Because of their brown body, this species may even be mistaken for the venomous brown recluse, though the former can be mostly distinguished by the dark stripes running through its abdomen.
Funnel Web Grass Spider

Image Credits: Nature.mdc.mo.gov, I.pinimg.com, Upload.wikimedia.org, Extension.usu.edu, Objects.liquidweb.services, Suttonmass.org

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