Brown recluse spiders often cause concern, leading many to mistake common brown spiders for them. Understanding spider habitats and appearances can help identify species present in a region. This article clarifies the presence of brown recluses in Utah and discusses common lookalikes.
Are Brown Recluses Native to Utah?
Brown recluse spiders (Loxosceles reclusa) are not native or established residents of Utah. Their natural habitat primarily spans the south-central United States, encompassing states such as Kansas, Oklahoma, Texas, and Missouri. While isolated individual brown recluses might rarely be transported to Utah, perhaps through moving boxes or cargo, these instances do not signify an established or breeding population within the state. Any reported sightings outside their known range are typically isolated occurrences and do not indicate a widespread presence.
The desert recluse (Loxosceles deserta), a closely related species, is found in parts of southern Utah. This spider shares a similar appearance with the brown recluse, which can lead to misidentification. However, the desert recluse is also generally shy and prefers arid environments away from human dwellings.
Spiders Commonly Mistaken for Brown Recluses in Utah
Since true brown recluse spiders are not established in Utah, many other local spider species are frequently mistaken for them due to their brown coloration or general body shape.
One common example is the hobo spider (Eratigena agrestis), which is prevalent in Utah homes, particularly from August to October. Hobo spiders are brown with a grayish abdominal area and may have faint patterns, but they lack the distinct violin-shaped marking found on a brown recluse.
Wolf spiders (family Lycosidae) are another group often confused with brown recluses. These are typically larger and hairier spiders, ranging from gray to dark brown, and often exhibit distinct stripes or markings on their backs. Unlike brown recluses, wolf spiders possess eight eyes arranged in three rows, and they are active hunters that do not construct webs for prey capture.
Yellow sac spiders (Cheiracanthium inclusum) are common household spiders in Utah that are sometimes mistaken for recluses. These spiders are pale yellow or tan, often with a greenish tinge on their abdomen, and they do not have the violin marking. Yellow sac spiders build small, white silken retreats in corners where walls and ceilings meet, and while their bites can be painful, they are not medically significant for humans.
Other spiders that might be confused with brown recluses include crevice-weaving spiders (Filistatidae) and cellar spiders (Pholcidae). Crevice-weaving spiders, found more often in southern Utah, can have six eyes like recluses but are harmless. Cellar spiders, also known as “daddy long-legs,” have long, slender legs and are not considered a threat.
What to Do if You Suspect a Spider Bite
If you suspect a spider bite, clean the area thoroughly with mild soap and water to prevent infection. Apply a cool compress or ice pack regularly and elevate the affected limb to reduce pain and swelling. Over-the-counter pain relievers and antihistamines can help with discomfort and itching. Seek medical attention if the pain becomes severe, if redness or swelling spreads significantly, or if you observe signs of infection like increasing warmth, pus, or red streaks. Medical consultation is also recommended for systemic symptoms such as fever, chills, nausea, vomiting, or difficulty breathing, or if you are unsure about the type of spider that caused the bite.