Ed. Note: The following posting was originally published on What’s That Bug? by Daniel Marlos
25 June 2012
Location: Mt Washington, Los Angeles, CA
Yesterday while cleaning off the patio furniture, we uncovered this Brown Widow‘s Lair under the rear right leg. to be continued …
We did not realize she was there until a spray from the hose onto what we thought was an abandoned cobweb caused her to scuttle along a stand of silk revealing her orange hourglass marking.
The Brown Widow, Latrodectus geometricus, is also known as the Geometric Button Spider or the Brown Button Spider according to BugGuide, which lists its identifying features as: “The brown widow is highly variable in color. It may be almost white to almost black. Typically, it is a light to medium brown, with an orange-to-yellow hourglass marking on the underside of the abdomen; the coloration of the hourglass often is a good indication of this species. The leg segments are banded, with one half of each segment lighter in color than the other half. The back often has a row of white spots (rarely orange or light blue), and there are a few white stripes on each side. Darker individuals lack these markings and are difficult to distinguish from black widows. If an eggsac is present, this is the best identifying characteristic. Brown widow eggsacs are tan, spherical, and have many small tufts of silk sticking out from them. They resemble a ‘sandspur.’ The other widows make white, smooth eggsacs that tend to be pear-shaped.” The little lady we uncovered had several egg cases. BugGuide also notes: “Found around buildings in tropical climates.(1) However, it is an introduced species and is the most human-adapted of the species occurring in the South Eastern US. Its webs may occur anywhere there is sufficient space to make one. It may be extremely abundant on houses and other man-made structures (e.g., barns, fences, guard rails, bridges). It reproduces frequently and disperses rapidly, making it nearly impossible to control.”
Though we see Black Widow’s with some degree of frequency around the offices, we haven’t noticed any in recent years. We can’t help but wonder if our local species is being displaced by this recent introduction. While the Black Widow’s bite is often regarded as potentially dangerous to sensitive individuals, the Brown Widow’s bite is generally not as serious. Here is BugGuide‘s assessment: “It is recognized that this particular species of widow is most likely not medically significant (not an immediate medical concern to those who are bitten). (Net Ref (4)) The brown widow produces clinical effects similar to that of the black widow but the typical symptoms and signs being milder and tending to be restricted to the bite site and surrounding tissues.” We would still caution readers to avoid Brown Widow as the bite might still be unpleasant if not dangerous.