Volume 52, Number 2, September 2005:
Checklist of Kansas Orbweaving Spiders

Text-only version

ISSUE HOME PAGE

ABOUT THIS ISSUE
- about KSN
- about the author

IN THIS ISSUE
- introduction
- 1-6
- 7-16
- the orb web, prey, and economic importance
- 17-22
- 23-28
- predators, parasites and spider defenses
- Kansas orb weavers
- argiopidae
- tetragnathidae
- references
- acknowledgements

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Checklist of Kansas Orbweaving Spiders
by Hank Guarisco

CHECKLIST OF KANSAS ORBWEAVING SPIDERS
by
Hank Guarisco
Sternberg Museum of Natural History
Fort Hays State University

INTRODUCTION
Arguably, the most interesting aspect of spider behavior is the construction of a web. The delicate beauty and intricacy of the orb web has fascinated people of many cultures through the ages. The Greek goddess Athena condemned Arachne, a skilled weaver who dared to challenge her, to a life of web spinning by turning her into a spider. Anyone fortunate enough to have witnessed its construction, will wonder how does the spider do it! Early investigations of the "mental powers" of spiders and behavioral "instinct" gave way to controlled experiments which elucidated the influence of drugs, coffee, alcohol as well as other parameters upon web structure (52).

A fossil silk spinning organ (spinneret) from the Devonian is evidence that spiders have produced silk over the past 380 million years (49). Because spider silk is a lightweight, flexible fiber of extraordinary strength and toughness, there have been recent attempts to produce this protein-based "biopolymer" artificially. Artificial dragline silk with many of the desirable properties of natural silk was produced by inserting the dragline silk genes of two, large orbweavers into two mammalian cell lines. When the process is perfected, these synthetic fibers could be used as sutures in microsurgery as well as provide a "green" alternative to nylon fibers in a variety of industrial applications since they will eventually dissolve in wet environments (22).

Orbweaving spiders are "sit-and-wait" predators which generally build a web to capture prey. This group has been divided into two closely related families: the Araneidae (or Argiopidae) and the Tetragnathidae. Although two more distantly related families (Theridiosomatidae and Uloboridae) have members which construct orb-like webs, they are not included in this checklist. Orb web building behavior may have arisen several times in diverse spider groups, although some scientists believe this ability could only have arisen once (5, 34, 48).

The Araneidae include some of the most commonly encountered spiders around homes and gardens, such as the black and yellow garden spider (Argiope aurantia), as well as the rare bolas spider, Mastophora dizzydeani, which was named "in honor of one of the greatest baseball pitchers of all time, Jerome 'Dizzy' Dean" (9). Instead of constructing a web, bolas spiders swing a drop of glue suspended at the end of a silk strand at approaching prey. This weapon is reminiscent of the bolas used by South American gauchos to entangle the legs of cattle. Hence, members of the genus Mastophora have earned the common name of "bolas spider" (53).

The Tetragnathidae, or "long-jawed" spiders, usually have long bodies and legs, large forwardly projecting jaws (chelicerae), and occur near water. These characteristics are
most pronounced in members of the genus Tetragnatha, which often consume many mosquitoes and midges during their lifetimes.Spiders of the genus Pachygnatha are sit and wait predators which don't build webs. They occur on tree trunks in moist woods and capture insects that come along.

Worldwide, there are 3,846 described species of orbweavers (45). There are currently 63 different orbweavers known in Kansas.