conical trashline orbweaver

not listed

NNR - Unranked

not listed

Conical trashline orbweaver is a small spider. It occurs in Europe and North America. It occurs throughout the United States but is mostly absent from the Great Plains and the southeast. Adults are found from mid-May through summer in woodlands.

The female is 3⁄16″ to ¼″ (4.41 to 5.81 mm) in length and has a ¼″ to 7⁄16″ (6 to 11 mm) legspan.

The front part of the body (cephalothorax) is much smaller than the abdomen and is strongly narrowed in front. The upper side (carapace) is dark brown to almost black with patterns of dark gray. The area between the eyes and the middle of the carapace is lightly covered with long, fine, white hairs.

There are eight eyes arranged in two parallel rows of four eyes each. The rear row is curved forward, the front row is straight or slightly curved backward. All of the eyes are on prominent knob-like projections (tubercles). All of the eyes are small, but the front (anterior) middle (median) eyes (AME) are larger than the rest. The rear (posterior) median eyes (PME) are very close together, almost touching.

The abdomen is large, oval, rounded, and highest in front. There is a large, angled hump at the rear. The length of the hump varies between individuals, but it often extends, cone-like, beyond the spinnerets. This is the feature that gives the spider the first part of its common name. The upper side of the abdomen is pale with a distinct, dark, leaf-shaped pattern (folium) in the middle.

The legs are short, spiny, and pale brown, with indistinct dark brown rings at the tips of most segments. The front two pairs project forward, the hind two pairs project backward. The last segment (tarsus) on each leg has three claws at the tip, though these are not visible to the naked eye.

The male is much smaller, ⅛″ to 3⁄16″ (3.63 to 4.35 mm) in length. The abdomen is elongated, the hump is smaller, and the coloration is more muted.

Female Body Length: 3⁄16″ to ¼″ (4.41 to 5.81 mm)

Male Body Length: ⅛″ to 3⁄16″ (3.63 to 4.35 mm)

Legspan: ¼″ to 7⁄16″ (6 to 11 mm)

The web is large and oval. It is called an “orb”, which gives this family of spiders its common name. It is made up of about 30 to 50 radii that are not sticky, and threads that are sticky spiraling all the way to the center. It hangs vertically about six feet off the ground. It may be wider than tall.

There is often a line of heavy silk (stabilimentum) down the center of the web adorned with parts of dead insects and bits of leaves. This “trashline” provides camouflage for the spider sitting in the center of the hub. It is the feature that gives the spider the second part of its common name.

No retreat is constructed.

When at rest, the cephalothorax is completely covered by the first and second pairs of legs.

Sources

24, 29, 30, 82, 83.

Cyclosa conica Conical trashline orbweaver

Cyclosa conica found on Barnes Prairie, Racine Co., WI photo taken July 3, 2021. This critter was about 2 mm.

Location: Barnes Prairie, Racine Co., WI

Cyclosa conica found on Barnes Prairie, Racine Co., WI photo taken July 3, 2021. This critter was about 2 mm.