Genus Agelenopsis - Grass Spiders

Age·le·nop·sis

Author: Giebel, 1869

13 species in North America listed at Transylvania U., Kentucky

NOTE: When measuring the size of a spider, only the body length is measured (do not include the legs).

The larger specimens (depending on species) can get up to approximately 3/4" (19 mm): body length only

The Web:

For this genus of spiders, the web is a horizontal, sheet-like web, with a small funnel-like tube off to a side (or for some species, the middle of the web) and a 3-dimensional barrier web over the top. When a flying insect hits the barrier, it falls into the sheet below. The funnel (or tube) is what the family (Agelenidae) is named for, and is used by the spider for hunting. The spider will lie in wait in the funnel, and when an insect flies hits the barrier and falls on the web, the spider will rush out, very quickly check to see if it is prey, and if it is prey, bite it. The venom is fast-acting on the prey, so once the prey is subdued (less than a second or two), the spider will drag the prey back into the funnel (for safety while eating, and to prevent other insects from recognizing the danger that lurks below on the web...)

For Agelenopsis spp. spiders, the web is not sticky. If the insect lands/falls on the web, the web will actually become tangled around the prey's feet, temporarily ensnaring it in the web.

Web Locations:

The funnel web for Agelenopsis is a distinctive web, and often is noticed in bushes and grass, especially in the early fall mornings, where the dew has collected on the web. The webs can be expansive, covering several square feet, or just small webs in the grass.

The Spider:

These spiders are very common throughout the United States and Canada. Their webs will "litter" the low-hanging shrubs and grass in summer to early fall, and are really noticable after a nice early morning dew. They are fairly easily identified: a "small" brown spider with longitudinal striping, the arrangement of their eight eyes into two rows. (The top curved row has four eyes and the bottom curved row has four eyes).

See

They also have two prominent hind spinnerets. A spinneret is a spider's silk spinning organ. They are usually on the underside of a spider's abdomen, to the rear. On many spiders, the spinnerets cannot be seen easily without flipping the spider over; however, with Agelenopsis, the spinnerets are readily seen without having to flip the spider over. Agelenopsis also have somewhat indistinct bands on their legs.

Note the spinnerets in each image.

Agelenopsis spp. spiders are "lightning-quick"; often people only get a glance of it before it disappears behind or under something.

Throughout the United States and Canada

It is common in open areas, gardens, and woodlands. Depending on the style of siding on a structure (wood shakes, some vinyl sidings, porch eaves and beams, bricks with cracked/broken mortar, etc.), it will build a web in a corner, near a light source that will attact insects. (The structure type has to be able to form some sort of gap or recess for the "funnel" to retreat into.)

Often in the summer to early fall.

Primarily insects.

Agelenopsis funnel-web spiders only live for a year, dying in the fall (typically by the first frost).

Males:

Males spend most of their life wandering in search of a mate. Shortly after mating, the male often dies.

Females:

The females typically do not wander from the web, and if they do, it is typically to find a new location to build the next web. Females spend most of their time capturing and eating prey, building up their strength to mate and lay eggs. Females do not search for mates, but rather, wait for the males to wander by and find them. In the fall, after mating, the females will deposit a disc-shaped egg sac in a crevice, and then die - often still clinging to the egg sac. (1)

Being Bitten:

These spiders are docile and non-aggressive. They will flee at the first sign of a threat and will not bite unless they feel threatened without an option to escape. (e.g. - Trying to pick the spider up).

Seyler, 1942(2)