The name “Brown Recluse” describes the color and the habits of this increasingly infamous spider. Brown Recluse spiders, with the scientific name of Loxosceles reclusa are one of the few spiders in the United States that are known to be very harmful to humans.
Identify Brown Recluse Spiders
Adult Brown Recluse spiders are yellowish-tan to dark brown. They have long, thin gray to dark brown legs covered with very short, dark hairs. Both male and female spiders are similar in appearance and are equally venomous. The most distinguishing mark on a brown recluse spider is the presence of a dark brown or black violin or fiddle on its back with the violin’s “neck” pointing toward the rear of its body. For this reason, they are sometimes called “violin spiders” or “fiddleback spiders”.
Brown Recluse Characteristics
The Brown Recluse is regarded by some as more dangerous than the Black Widow spider because it is considered a house spider and isn’t as simple to identify.
The Brown Recluse spider will lunge and bite the prey in a vulnerable area and immediately back away while the venom acts to quickly paralyze them. The spider then moves in to feed. The same venom that acts to liquefy an insect’s innards for consumption also causes the “flesh rotting” appearances as shown.
During the day, Brown Recluse spiders spend their time in quiet, undisturbed places. If they are seen roaming during the day, pesticide applications, hunger, overcrowding or a desire to find a mate has probably brought them out. Sometimes they will be discovered trapped within a smooth surface such as a bathtub or sink. But because they are primarily nocturnal, they will typically begin to stray from their hiding place about an hour or two after dark. This is when they spend their time hunting for food. This explains why many bites occur while victims are sleeping. While they are hunting for food, they may crawl up onto a bed and bite when the victim inadvertently rolls onto the spider during normal sleep movements.
Brown Recluse spiders are remarkably resilient and can survive 6 to 12 months with no food or water and have an average life span of 2 to 4 years. In laboratory conditions, they have lived as long as 7 years.
The Black Widow Spider (Latrodectus spp.) is a spider notorious for its neurotoxic venom. It is a large widow spider found throughout the world and commonly associated with urban habitats or agricultural areas.
Identify Black Widow Spiders
Adult female black widow spiders are gloss black with an hourglass shaped marking on the underside of its abdomen which is red. The male spider’s hourglass color is yellow to white to various shades of orange and red. They also bear a small, usually red (colors vary) dot near the spinnerets, which is separate from the hourglass. In L. variolus, the two halves of the hourglass shape may be separated into two separate patches. A large female black widow spider can grow to about 1.5 inches (37 mm), counting legspan. The body is about 0.5-0.6 inches (12-15 mm). Male black widow spiders are half the size of the female or smaller. They have longer legs and a smaller abdomen in relation to their body size. They are also usually dark brown with varying colors of stripes/dots, with no hourglass mark. Adult males can be distinguished from juvenile females by their more-slender body, longer legs and large pedipalps typical of most other male spiders.
Black Widow Characteristics
Although their venom is extremely potent, (15 times more potent than that of the rattlesnakes; it is also reported to be much more potent than the venom of cobras and coral snakes), these spiders are not especially large. Compared to many other species of spiders, their chelicerae are not very large or powerful. In the case of a mature female, the hollow, needle shaped part of each chelicera, the part that penetrates the skin, is approximately 1.0 mm (about .04 inch) long, long enough to inject the venom to a point where it can be harmful. The males, being much smaller, injects far less venom with smaller chelicerae. The actual amount injected, even by a mature female, is very small in physical volume. When this small amount of venom is diffused throughout the body of a healthy, mature human, it usually does not amount to a fatal dose (though it can produce the very unpleasant symptoms of latrodectism).
Black widow spiders are nocturnal and, thus, are active at night. They prefer dark corners or crevices. They are said to avoid human dwellings, but you can find them in such areas as outhouses and garages. Only the female black widow bites humans, and she bites only when disturbed.
The Hobo Spider (Tegenaria agrestis.) has spun below the radar for many years. Despite their increasing range and population, public awareness of these spiders has been surprisingly low, primarily because the Brown Recluse Spider has been inaccurately blamed for the insidious effects that people receive from Hobo spider bites.
Identify Hobo Spiders
Hobo Spiders are brown and measure roughly 12 to 18 mm in length. Their legs show no distinct rings and have short hairs. Their abdomens have several chevron shaped markings. Males are distinctively different from females in that they have two large palps that look like boxing gloves. These palps are often mistaken for fangs or venom sacs, but they are in fact the male genitalia. The females also have these palps, but the ends are not ‘swollen’ as they are on the males. Females tend to have a larger abdomen when compared to males.
Hobo Spider Characteristics
The hobo spider creates a non-sticky (in spider standards) trip web that doesn’t permanently stick insects to the web. Instead, once the prey trips on the web the hobo spider attacks the prey before it can get away. This along with its poor eye site explains why they are noticeably more aggressive to humans then other spiders. They have to attack to eat otherwise it would die of starvation.
The hobo spider is known to be a fairly aggressive spider in its nature. When a hobo spider is tending to their eggsacs they tend to become even more aggressive and at that point they will attack. A hobo spider will usually bite a human due to getting trapped in clothing, in bed sheets, and being trapped next to the skin. The initial bite by the hobo spider usually is not painful, but in about thirty minutes a hard area will appear. Within 15 to 35 hours the sore will blister. The blister will break in around 24 hours, and the wound left behind generally will heal very slowly.
The Hobo spiders are not good climbers, and are usually found at ground or basement level. They sometimes climb up to a level of about four feet if the surface of the wall, etc. is sufficiently porous however they are not able to climb smoothe surfaces. Hobo spiders found in wash basins and bathtubs arrived there by falling down the slick porcelain surface; they did not come up through the drain.