orchard orbweaver

not listed

NNR - Unranked

not listed

Orchard orbweaver is a sedentary, small, brilliantly colored, long-jawed orb weaver. It occurs in the United States east of the Great Plains excepting Florida, and in adjacent Canadian provinces. It is one of the most common spiders in the eastern United States. It is less common in Minnesota, where it reaches the western extent of its range. It is found in forests, dense woodlands, woodland edges, shrubby meadows, gardens, and orchards.

The female is 3⁄16″ to 5⁄16″ (5.5 to 7.5 mm) in length, not including the legs, and has a ⅜″ to ⅞″ (10 to 22 mm) legspan. The male is much smaller, ⅛″ (3.5 to 4.0 mm) long. The species epithet venusta is Latin for “beautiful” and it is easy to see why it was given to this spider.

The front part of the body (cephalothorax) of the female is longer than wide and moderately arched. The hardened plate (carapace) covering the cephalothorax is yellowish-brown with a narrow, longitudinal, dark stripe in the middle, and a thin dark line on each lateral margin.

The plate on the face above the upper lip (clypeus) is narrow. The jaw-like mouthparts (chelicerae) are very large. This is the feature that gives the family one part of its common name. There are eight eyes arranged in two nearly parallel rows of four eyes each. All of the eyes are small and nearly equal in size. On each side the anterior lateral eye (ALE) and posterior lateral eye (PLE) are very close together.

The abdomen is oval and about two times longer than wide. It is broadly rounded at the front and rear, and projects forward far above the carapace. It is silvery-white above with dark brown or green markings. There is a thick dark stripe in the middle with four pairs of thin branches. The front pair is thick, arcs toward the sides, then extends to the rear of the abdomen. The other branches are thin, straight, and project obliquely to the rear. Often one or more of the pairs of the thin branches are reduced or missing. There is also a yellow stripe on each side. Sometimes there is a bright copper-red or orangish-yellow spot on each side near the rear, and a similarly colored large spot on the underside near the middle.

The legs are long and slender. The first, second, and fourth pairs of legs are very long, much longer than the body. On the front and second pairs of legs the fifth segment (tibia) and sixth segment (metatarsus) are not studded with thorn-like points. On the hind legs the basal half of the third segment (femur) has a fringe of hairs on the outer face. The last segment (tarsus) on each leg is hairy and has three claws at the tip, though these are not visible to the naked eye.

Female Body Length: 3⁄16″ to 5⁄16″ (5.5 to 7.5 mm)

Male Body Length: ⅛″ (3.5 to 4.0 mm)

Legspan: ⅜″ to ⅞″ (10 to 22 mm)

The female spins a circular web about 12″ in diameter with about 30 radii. This web is called an “orb”, which gives this family of spiders one part of its common name. The web is built in an open, well-lighted spot of a low bush or a small tree. When construction of the orb is complete the spider bites out the threads in the center, resulting in an “open web”. The orb may be at any angle but is usually nearly horizontal. When horizontal there is usually a barrier beneath it consisting of a few loose threads spreading in all directions.

Forests, dense woodlands, woodland edges, shrubby meadows, gardens, and orchards.

The spider rests upside down on the bottom of the web with its abdomen in or at the edge of the opening in the middle.

Orchard orbweaver can byte with its long jaws, but the bite is not considered harmful.

Eggs are enclosed in silken sacs and attached to twigs or leaves near the web. The eggs hatch in the spring. Adults do not survive the winter.

Sources

24, 29, 30.

Common

Orchard orbweaver is was formerly thought to occur from southern Canada to northern South America. A recently published DNA study (Ballesteros and Hormiga, 2018) showed that spiders from Florida to South America comprise a cryptic species, one that appears identical but is genetically distinct. The name Leucauge venusta is now restricted to spiders in the United States north of Florida. Spiders in Florida and south to Brazil are now classified as Mabel orchard orbweaver (Leucauge argyrobapta).

Leucauge venusta orchard orbweaver

About 3 mm long, its web was on Solomon's seal leaves.

Location: Woodbury, Minnesota