Types of Spiders in Boise, Idaho
There are many genera of Wolf Spider, ranging in body size from less than 1 mm to 5 inches. They have eight eyes arranged in three rows. The bottom row consists of four small eyes, the middle row has two very large eyes, and the top row has two medium-sized eyes. They depend on their eyesight, which is quite good, to hunt. Their sense of touch is also acute. Because they depend on camouflage for protection, they do not have the flashy appearance of some other kinds of spiders. In general their coloration is appropriate to their favorite habitat.
The keys to the identification of the Hobo Spider will be the eye arrangement and the pattern of darker “fishbone” or chevron stripes on their upper abdomen. The 8 eyes are in two parallel rows of 4 ocelli across the front of the cephalothorax, with both rows forming straight lines. This has become a very common spider in homes especially in basements, crawl spaces, and other lower areas of the structures.
Brown Recluse spiders have 6 eyes, arranged as 3 pairs in an arc across the front. Most spiders have 8 eyes, and no other groups have the eyes placed in the same pattern as the Brown Recluse spiders. The name “violin” or “fiddleback” comes from the dark violin-shaped pattern on the top of these spiders.
The body of the female black widow is about ½ inch long, glossy with a nearly globe-like abdomen. The abdomen has two triangular red spots on its underside arranged in such a way that the spots look like an hourglass.
House spiders are the most frequently found in human dwelling places. Some of the more prevalent house spider species include the common house spider, the domestic house spider, the aggressive house spider and the brown house spider. Their exteriors and sternums are yellow or brown in color. Their abdomens are gray and marked with white, while their legs are brown and darkly banded. Males are smaller than females, measuring only four millimeters in length as opposed to the female’s eight.
As their name suggests, they are found outdoors and in gardens. Garden spiders are not aggressive and are more likely to retreat from than attack humans. However, in cases of extreme provocation, garden spiders may bite. Their bites are harmless to humans. They measure approximately one inch in length or larger and are often marked vividly in black and yellow.
The Jumping Spider family (Salticidae) contains more than 500 described genera and about 5,000 described species, making it the largest family of spiders. Jumping spiders have good vision and use it for hunting and navigating. They are capable of jumping from place to place, secured by a silk tether. Adults rarely grow larger than one inch. Some common house jumping spiders appear black with white markings along the abdomen.
There are several species of Sac Spiders in the U.S., and for whatever reason they appear to be more inclined to bite people with less provocation. The bite from a Sac Spider is said to produce “instant, intense stinging pain”, followed by swelling, redness, and then itching at the site of the bite. There likely will also be a necrotic lesion formed due to the injection of the cytotoxin venom of these spiders, and it has been suggested that many times, when Violin Spiders have been accused of biting people in areas outside their range, it could be the sac spiders instead that are the true cause.