This new widow type spider is originally from South Africa, has made its way into Orange County California. Daniel Wheeler, owner of a pest control company in that area, said he has seen a big increase in sightings of this invader in Huntington Beach, Fountain Valley, Irvine, Costa Mesa, Norco and Corona California.
Even though the brown widow became well entrenched in San Diego and Los Angeles areas in early 2003, it had not been seen much in Orange County. It was only a matter of time before it moved into the Orange County.. This spider looks similar to the western black widow in shape and size but its coloring is tan to brown with black accent markings. It does have the same hourglass shape on the under belly but it's in shades of orange. The webbing for each is the same irregular type. The egg sacs for this spider have multiple silk spikes projecting out from the surface rather than the smooth shell of the black widow egg sack. The brown widow's egg sack has been described as looking like a large pollen grain. Besides the color of this spider, the other differences between these two widow spiders are as follows:
1. The Brown Widow will be found in more exposed areas than a black widow.
2. It is also very shy in comparison to the black widow and will retreat when disturbed.
3. Even though this spider’s venom is twice as toxic as the black widow but it releases less venom when it bites.
4. The Black Widow egg sack is a cream color and round while the Brown Widow egg sack is cream color but has little spikes all around the sack
"They are definitely dangerously poisonous," said Daniel. But, because they release less venom when they do bite they are less dangerous than the native western black widow according to some experts.
Symptoms of brown widow bites are not much different from the bite of normal household spiders. However, there has been a report of a verified brown widow bite manifesting more severe symptoms that required hospitalization of the bite victim. This new invader looks like it is beginning to occupy the same niche as western black widows so therefore, there may be a shift in the species composition. Considering that the brown widow is less dangerous and may be replacing the native western black widow from habitats, it is conceivable that the risk of serious injury from overall spider bite may decrease in southern California as the brown widow spreads.
David Wheeler, DAVID WHEELER'S PEST CONTROL, http://www.wheelerspc.com