What is a red widow?
By Chelsie Vandaveer
August 13, 2003
Series: | 1 | | 2 | | 3 |
Suggested Reading—>Click here.
The red widow (Latrodectus bishopi Kaston) is one of five species of widow spiders in North America. It is endemic (limited in its range) to the scrub habitats along the central Florida peninsula. The red widow was not even discovered and named until 1938.
Widow spiders belong to the Family: Theridiidae, those spiders having specialized spines (comb structure) on the tarsi (tarsus, end segment of the leg) of the fourth pair of legs. These tarsi enable web spinners to manipulate their silk into various shaped webs. Widow spiders are known for their tangled webs usually hidden under logs, in old animal burrows, and dark, undisturbed places in buildings.
Unlike its cousins, the red widow constructs its web in the open, spread between the fronds of saw palmetto (Serenoa repens (W. Bartram) Small) or scrub palmetto (Sabal etonia Swingle ex Nash). According to Petra Sierwald and Thomas Fenzl, "The base of the web consists of a large, dense, slightly convex sheet, with an extensive three-dimensional large-meshed network of threads above the sheet and a densely woven, funnel-shaped retreat attached to the convex sheet." ("Argyrodes in Webs of the Floridian Red Widow Spider (Araneae: Theridiidae)", Petra Sierwald and Thomas Fenzl, Florida Entomologist, Vol. 82, no. 2, 1999)
Very little is known about the red widow spider. Every ten to twenty years, the population erupts then drops. James E. Carrel studied these arachnids from 1987 to 2000 attempting to correlate the wild fluctuations with weather patterns, predation, or wild fires.
Even finding the spiders to study is difficult in scrub habitats because red widow silk is extremely fine and webs are seldom noticed.
Although, the population dynamics of red widows is still not understood, Carrel's observations discovered something of use for other entomologists doing field studies. The late winter fogs of the scrub habitats condense on the distinctive webs and the early morning sunlight highlights these webs across the prairies of palmettos. The spider locations can be flagged for further study. ("Population Dynamics of the Red Widow Spider (Araneae: Theridiidae)", James E. Carrel, Florida Entomologist, Vol. 84, no. 3, 2001)
The Florida Department of Agriculture and Consumer Services has a great article, "Venomous Spiders in Florida" by G.B. Edwards with photographs by J.L. Castner, L. Buss, and J. Lotz. Although having a close encounter of the wrong kind is rare, it is advisable to know what spiders are dangerous. To learn more and view photographs of venomous spiders, click on the link:
http://www.doacs.state.fl.us/pi/enpp/ento/venomousspiders.html
The Palm and Cycad Societies of Australia has posted photographs of saw palmetto, Serenoa repens. To view the photographs, click on the link:
http://www.pacsoa.org.au/palms/Serenoa/repens.html
Series: | 1 | | 2 | | 3 |
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