Black and Brown Widows
Black widows are shiny black spiders with red hourglass markings on the abdomen.
They are commonly found in the southern States, preferring temperate locations. They make their homes in dark, sheltered locations, like garages, woodpiles, the underside of window ledges or in plant debris. Their natural predator is the mud-dauber wasp.
These spiders are nocturnal, shy, and generally non-aggressive. They are most active at night and will seldom live near other spiders. They only “socialize” during mating, and do not often bite humans unless their web is disturbed. Bites can be quite painful, but rarely fatal. Anyone bitten by a black widow should seek medical treatment.
The black widow’s cousin, the brown widow, can be identified by its brown color, banded legs and uniquely patterned abdomen. Southern California has seen an increase in brown widow populations recently – they are taking over black widow territory. The brown widow is not as venomous and they are even less likely to bite a human, so this may be a good thing.
Black and brown widows will prey on common household pests like ants, roaches, scorpions, beetles, and grasshoppers. They can survive up to a year without food.
The brown recluse is a small, brown spider (the size of a quarter) with brown violin markings on its back. They will live in dark, undisturbed areas, under logs, in rock formations, woodpiles and other debris. Brown recluses are hunting spiders and do not often build webs – they prefer to actively chase their prey. They hunt at night, and are resilient to most weather conditions. Cobweb spiders and cellar spiders are the brown recluse’s natural predators.
Though their bites can become quite serious, damaging human tissue and causing severe wounds, they do not bite often. The brown recluse is not an aggressive spider and usually only bites after physical pressure has been applied to its body (rolling over one in bed, for example). The bites are not initially painful and it make take a few hours to even notice their presence. Some people experience necrotic lesions in response to the bites, so it is important to seek medical attention immediately, if you believe you’ve been bitten.
California Trapdoor Spiders
The California trapdoor spider is a medium to large spider, dark in color with a thick body and thick legs. They construct burrows in the ground with soil, dirt, silk and plant debris. These burrows help them hunt; instead of catching insects in webs, the trapdoor spider will wait for approaching prey, and launch itself out of the burrow to drag the meal inside. Insects get caught in the silken walls and cannot easily escape. The “door” to these spiders’ burrows is camouflaged with dirt and plants, so it can be difficult to spot.
California trapdoors are an aggressive species of spider. Many people keep them as pets, but because of their volatile nature, they should only be handled by professionals. The trapdoor spider’s bite, while not dangerous to humans, can be very painful.
They prefer to inhabit gardens, riverbeds or other areas with soft soil. Sometimes, they will venture into homes, but will not stay long, as they cannot burrow or hunt. Trapdoor spiders have a long lifespan of up to 20 years.
In Southern California, there are a few different types of sac spiders, but the yellow sac spider is most common. They can grow up to 1/4th of an inch in length, with darkened “feet” and a light yellow color.
Yellow sac spiders feed on regular household insects, other spiders, and sometimes exhibit cannibalistic behavior by eating their own eggs when food is scarce. They are predominantly hunting spiders and their webs are intended for rest – they do not use webbing to catch prey. Like many spiders, they are mostly nocturnal, and can be found home in their webs during the day.
Sac spider bites can be painful initially and they are often provoked to bite in close-quarters contact (in a bed, stepping on them, etc.). However, these bites are not dangerous, with victims experiencing some minor itching and a raised bump for a few days after the encounter.