When a widow spider is trapped, it is unlikely to bite, preferring to play dead or flick silk at the potential threat; bites occur when they cannot escape.Levi also noted that study of the genus had been contentious; in 1902, both Widow spiders are found on every continent of the world except Antarctica. 1983. "Knopie-Spider" bite in Southern Africa. Is the redback spider here to stay? New Zealand J Ag. 2005a. Pattern of sperm transfer in redback spiders: implications for sperm competition and male sacrifice. The spider genus Anava, A., and Y. Lubin. Tree of Life design and icons copyright © 1995-2004
Soc. 2:634-638.Forster, L. M. 1984. Introduction. Notes on the life habits and potency of the venom of the three Snow, L. S. E., A. Abdel-Mesih, and M. C. B. Andrade. B. Kreigler, J. M. van Zyl, B. J. van del Walt, A. S. Dippenaar, and P. P. van Jaarsveld. Value of male remating and functional sterility in redback spiders. The Australian redback spider (Forster, L. M. 1985. Watch Queue Queue. This ancestor diversified over time into several descendent subgroups, which are represented as internal nodes and terminal taxa to the right.You can click on the root to travel down the Tree of Life all the way to the root of all Life, and you can click on the names of descendent subgroups to travel up the Tree of Life all the way to individual species.For more information on ToL tree formatting, please see The male palp (intromittent organ) is distinctive with a long spiral embolus. The basal branching point in the tree represents the ancestor of the other groups in the tree. The bite itself is usually not perceived but local pain may occur several minutes after the bite. R. Soc. Proc. Latrodectus elegans. Behav. Spider venoms and their effect. Some species adapt well to synanthropic (human-altered) conditions and are readily dispersed by humans (Forster, 1984; 1985; Forster and Forster, 1999; Garb et al., 2004; Ono, 1995; Ori et al., 1996). (2004) have produced the first phylogeny of Abalos, J. W. 1962.
Taxonavigation .
1999. Widow spiders (genus Latrodectus) are widely feared but poorly known.They are a medically important group with a worldwide distribution. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. a group of organisms representing a branch of the Tree of Life. Br. Ethology 111:1-17.Snow, L. S. E., and M. C. B. Andrade. Introduction of widow spiders into Japan. Bull. 150:58-59.Forster, L. M. 1992. Giftige und gefährliche Spinnentiere. Indoor nests are in dark, undisturbed places such as under desks or furniture or in a basement.As with other web-weavers, these spiders have very poor eyesight and depend on vibrations reaching them through their webs to find trapped prey or warn them of larger threats. 1993. Br. Science 271:70-72.Andrade, M. C. B. 13:331-335.Finlayson, M. H. 1956. 2005b. J. Arachnol. Watch Queue Queue
With a recent report of occurrence of Latrodectus geometricus from Pune, Maharashtra (Shukla & Gour-Broome 2007) and Latrodectus elegans from Thawai, Manipur (Kananbala et al. European araneism. (In Japanese). However, such general "common names" are of limited use as the diversity of species is much greater. (2004), based on cytochrome oxidase I sequence data. 1965. Broken copulatory organs are low-cost adaptations to sperm competition in redback spiders. Proc. Female hunger can explain variation in cannibalistic behavior despite male sacrifice in redback spiders. Med. B. Kreigler, B. J. van del Walt, and P. P. van Jaarsveld.
47:111-119.Ross, K., and R. L. Smith. Black widow venom is a neurotoxin that can cause latrodectism, a mild to severe medical syndrome. Pages 299-309 Maretic, Z. 1967. These small spiders have an unusually potent venom containing the neurotoxin Female widow spiders are typically dark brown or a shiny black in colour when they are full grown, usually exhibiting a red or orange hourglass on the Like other members of the Theridiidae, widow spiders construct a web of irregular, tangled, sticky silken fibres. The famous red hourglass marking on the ventral part of the abdomen is not present in all species.
Evidence of insemination of multiple females by the male black widow spider, Latrodectus mactans (Araneae, Theridiidae).
2004. Latrodectism: Variations in clinical manifestations provoked by Maretic, Z. Spiders of New Zealand and their World-Wide Kin. The male mating system in a desert widow spider. 15:785-792. Med. All rights reserved.Click on an image to view larger version & data in a new window