striped orbweaver

not listed

NNR - Unranked

not listed

Striped orbweaver is a small grass orb-weaver spider. It occurs in North America across the northern half of the United States, in the southwest, and in southern Canada. It is found in forests on shrubs and on bare lower branches of trees, and in meadows and prairies on tall weeds and grasses.

The female is 3⁄16″ to 5⁄16″ (4.5 to 8.0 mm) in length and has a ½″ to ¾″ (12 to 20 mm) legspan. The front part of the body (cephalothorax) is longer than wide and much smaller than the abdomen. The upper side (carapace) is yellowish with a slender, dark, longitudinal stripe. The underside is dark brown.

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 small, but the middle (median) eyes are larger than the lateral eyes, and the posterior median eyes (PME) are slightly smaller than the anterior median eyes (AME). On each side the lateral eyes are widely separated from the median eyes and are almost touching each other. The PME are very close, touching or nearly touching each other. The median ocular area (MOA), the area defined by the middle four eyes, is more than twice as wide in front than at the rear.

The abdomen is long and narrow. On the female it is twice as long as wide and is narrowed in front to a broad point that hangs over the carapace. The rear end hangs over the silk-spinning organs (spinnerets). There are no low rounded humps (tubercles) in the shoulder (humeral) area. The color and markings on the upper side are variable. It is usually pale yellow with a pale brown stripe in the middle and two pale gray stripes on each side. The lateral stripes are sometimes also pale brown. All of the stripes are bordered by thin dark lines and run the entire length of the abdomen. There are usually eight tiny black spots, four equally spaced in each innermost lateral stripe. Occasionally the spots are large, sometimes they are absent. The underside of the abdomen is yellow with three dark stripes.

The legs are long, slender, and yellowish. The first pair of legs is the longest, the third pair is the shortest. The fifth segment (tibia) on the first and second pairs of legs are equally slender. There are no spines but there are numerous long, erect, stiff, bristly hairs. There are no dark rings and no black spots, but there is a narrow dark longitudinal stripe on the upper side of the tibia on all legs.

The male is much smaller, ⅛″ to 3⁄16″ (3.9 to 5.4 mm). The underside of the abdomen is black or almost black with a pale spot in the middle.

Female Body Length: 3⁄16″ to 5⁄16″ (4.5 to 8.0 mm)

Male Body Length: ⅛″ to 3⁄16″ (3.9 to 5.4 mm)

Legspan: ½″ to ¾″ (12 to 20 mm)

The web is small and hangs vertically. It is called an “orb”, which gives the family Araneidae its common name. The orb has sticky spirals and unsticky radii.

Forests on shrubs and on bare lower branches of trees; meadows and prairies on tall weeds and grasses.

May to October

Immature spiders overwinter and mature in the spring. Eggs are produced in the summer.

Sources

7, 24, 27, 29, 30, 82.

Larinia borealis, striped orbweaver (boreal striped orbweaver)

Out at the tallgrass prairie in Racine Co., WI, I found and photographed a number of these small, colorful orbweavers.

Larinia borealis, photographed in late afternoon at Barnes Prairie, Racine Co., WI on September 16, 2023. Webs were connected to tall grasses, and native tallgrass prairie forbs.

Larina borealis, striped orbweaver

Location: Barnes Prairie, Racine County, WI

Location: Barnes Prairie, Racine County, WI