The hobo spider (Eratigena agrestis), often called the “aggressive house spider”, was accidentally introduced to the northwestern United States in the 1980s and can be found today in the Pacific Northwest and parts of Canada. Hobo spider bites are quite serious and dangerous because they can cause several health problems and wounds around the bite area. The hobo spider is often confused with Loxosceles reclusa. You can observe the spider's color, size, web, and bite to identify hobo spiders.
Step
Part 1 of 3: Observing the Color and Size of Spiders
Step 1. Observe the spider with a brown body and yellow markings on its belly
The hobo spider has a brown forelimb which is where its legs, which are also brown, attach. Generally, when viewed closely, there is a brown pattern on the front of the spider's body. You may also see yellow streaks on the spider's lower body or belly. You may have to see the pattern using a microscope or magnifying glass.
Step 2. Know the size of the spider
Hobo spiders are generally smaller than other spider species. Male hobo spiders have a body length of 7-14 mm. The female hobo spider has a body length of 10-17 mm. To make sure that they are smaller, you can compare the hobo spider to Loxosceles reclusa.
The hobo spider also has shorter legs than other spiders. The hobo spider can stretch its legs 5-7 cm long
Step 3. Use a magnifying glass or microscope to observe the spider's pedipalps
The hobo spider's striking features can be clearly seen using a magnifying glass or microscope. Small body parts can help you identify hobo spiders.
- The male hobo spider has 2 large pedipalps. The pedipalps are located on both sides of the spider's head and mouth. Pedipalps look like boxing gloves when viewed under a microscope. The pedipalps are the male spider's genitals and may appear swollen. Female hobo spiders also have pedipalps but do not appear swollen.
- Also observe the thin, almost transparent hairs called "plumose setae" on the spider's body. You need a microscope with a strong lens to see it. These thin hairs grow evenly on the spider's body and are difficult to see with the eye.
Step 4. Make sure the hobo spider you find is not another spider species
Hobo spiders are often confused with Loxosceles reclusa or other spider species. However, you can identify some physical traits to confirm that the spider is a hobo spider.
- Make sure the spider has spots on its sternum (the flattened shell on the spider's upper body surrounded by the spider's legs). If there are 3-4 spots on the sternum, the spider is not a hobo spider.
- Notice the two long lines on the front of the spider's body, where the spider's legs attach. If it has these two long stripes, it's not a hobo spider. The hobo spider has a thin, inconspicuous pattern spread across its forelimb.
- Notice his shiny, hairless, dark orange feet. If it has these characteristics, it is not a hobo spider.
- Unlike Loxosceles reclusa, the hobo spider does not have dark bands on its legs or a violin-like pattern on its head. Unlike the hobo spider, Loxosceles reclusa also has no markings on its abdomen.
Part 2 of 3: Observing Cobwebs
Step 1. Make sure the net is above the ground
Hobo spiders are not vertical climbers. Therefore, hobo spiders generally build webs above ground or underground. If the web is above ground or underground, the web is from hobo spiders.
Step 2. Observe the spider web that is shaped like a funnel
The hobo spider is a species of spider that makes a funnel-shaped web. Hobo spiders use their long legs and running ability to create webs that are shaped like funnels or tubes.
- This net is usually attached between two objects that are above the ground, such as plants or tree trunks. Sometimes hobo spiders make nests under planks, basements, and among grass or vegetation.
- Unlike the hobo spider, Loxosceles reclusa cannot make webs. Therefore, if there is a funnel-shaped web around the spider's habitat, the spider is not Loxosceles reclusa.
Step 3. Make sure the net doesn't stick to the touch
Unlike other spiders, the hobo spider makes a non-sticky web. The web will make the prey fall and the hobo spider will immediately attack before the prey escapes.
Hobo spiders have poor eyesight. Therefore, hobo spiders are more aggressive towards humans than other spider species. The hobo spider behaves aggressively because if it does not attack, it will starve to death
Part 3 of 3: Observing Spider Bite
Step 1. Watch for blisters or open sores around the bite
Most hobo spider bites are painless at first. The bite is red and looks like a mosquito bite. Within 24 hours, the bite will blister. Within 24-36 hours, the blisters will open and fill with pus. At this time, your body will begin to react to the spider's venom.
Step 2. Watch for headaches, nausea, or fatigue
Common symptoms of hobo spider bites are headache, nausea, and fatigue. You may also experience short-term memory loss and visual disturbances when bitten by a hobo spider. These symptoms will appear within 24-36 hours.
If the hobo spider bite is not treated immediately, you will experience repeated side effects due to the venom in your body, such as headaches, nausea, vomiting, pain at the bite area, and flu-like symptoms
Step 3. Seek immediate medical attention when bitten by a hobo spider
If you are bitten by a hobo spider, immediately wash the bite area with an antiseptic. Check with your doctor for antibiotics or a tetanus shot, which can prevent infection.
