Spiders are one of the easily recognizable and beneficial creatures; despite this, many people have an inherent fear of them their bites and will not tolerate their presence. The vast majority of spiders living in Michigan are not even dangerous, let alone poisonous. As a matter-of-fact, it is rare to even come in contact with Michigan’s more hazardous species. In short, don’t panic over poisonous spiders in Michigan.
Most people associate spiders with the potential of venomous bites, but the danger of those bites is profoundly blown out of proportion. The majority of spiders are not at all dangerous to humans, only a small percentage. All spiders, even those that are venomous, are non-aggressive and will not (typically) bite unless they feel threatened or provoked; even then, only the more sizeable species have the capability of piercing human skin with their tiny fangs.
According to the Michigan Department of Natural Resources, there are only two species of venomous spiders living in Michigan: the Northern black widow and brown recluse.
Northern Black Widow
The northern black widow is native to Michigan and can be found throughout the state, especially in the lower peninsula. The black widow is relatively small, only growing to about a 1/2 inch long (1.5 inches if you include the legs). They are entirely black except for a distinct bright red, hourglass marking on the abdomen of the female (it is important to point out that the hourglass is incomplete in the middle). Males lack this trademark, but many have red or yellow bands on their abdomen or back.
Black widows are commonly lurking near or in woodpiles; many encounters with this spider occur as people are carrying firewood into the home. These spiders may also live in boxes, outdoor toilets, meter boxes, under eaves, and other various undisturbed places. Taking extra precautions when working in areas where black widows may live is beneficial; always be sure to wear gloves and pay attention.
Black widows rarely bite, as they are timid and prefer to flee an encounter. If a black widow bites you, however, you will need to seek medical attention immediately. Their bites are quite painful. They can cause acute latrodectism, a condition in which the spider’s venom spreads quickly throughout the body, causing constant, intense muscle contractions in all of the major muscle groups followed by painful and severe cramping. These muscle contractions (a condition called tetany) may include anxiety, dizziness, headache, tearing of the eyes, joint pain, and tremors.
Though death from a black widow bite is rare, and though symptoms will usually dissipate within three days, medical treatment can considerably lessen the unpleasantness of the symptoms by the use of antivenoms and muscle relaxers. Asn with many ailments, the elderly, extremely young, or very ill victims are at a higher risk for more severe complications.
Brown recluse spiders are about 0.5 in long with a dark violin-shaped mark on the combined head and midsection. They live in the south-central United States and can only survive in arid, undisturbed areas, such as rock or woodpiles.
Brown recluse bites don’t always hurt immediately. You may not know that you are suffering from their venom until other symptoms become present. Symptoms of a brown recluse bite include:
- Reddened skin that may precede a blister that forms at the site.
- Mild to intense itching and pain for 2 to 8 hours following the bite.
- An open sore with necrosis (a breakdown of tissue) that develops a week or more following the bite. This may take months to heal.
The brown recluse is not one of the indigenous species to Michigan and cannot survive in temperatures colder than 40°F, so they are infrequent in the state. It is believed that those that are found have come in on trucks originating in the southern United States.
Despite this, there are rare, isolated populations of these spiders living in the state. Still, the vast majority of Michiganders will never come within a half-mile of a brown recluse spider.
Dangers of Spiders and Their Bites
Most people concerned about the presence of spiders in the home worry about the potential of bites. Except for the aforementioned brown recluse and the black widow, none of the other species’ in Michigan pose as a threat to human health. This is not to say that these other spiders will not bite because they definitely can; even the bites of the non-venomous spiders can be painful. Spiders will most likely bite if they are handled, but most spider bites do not occur in this manner.
A more conventional yet still rare manner of a bite occurs when people are asleep. A spider will be lurking about beneath the covers, seeking the darkness and warm. A sleeping person can unknowingly move and startle the spider, which will then results in a bite before scampering away. The unsuspecting victim will then up with a painful or reddened bite, sometimes mistaking the spider bite for bed bugs.
It is imperative to note that it’s challenging for a medical professional to diagnose the perpetrator based solely on the appearance of a bite, though.
Many “spider” bites are bites from other insects that go unnoticed until a reddened, itchy, or painful spot occurs. These are likely reactions from the bites of mosquitos, gnats, and flies.
Spider eggs are also a threat, in the sense that a spider that lay eggs in the home will only create more spiders. These sacs look like furry, white balls, usually a little smaller than a marble. Destroying/removing spider eggs is essential in controlling spider a population.
When it comes to spiders, identification is key. We always ask our customers to try and save a specimen for our professionals to identify and treat accordingly.
Despite knowing the rarity of an encounter with a dangerous spider, it does not stop the vast majority of the public from letting out a shriek when spotted. Knowing what to look for is the most important step in avoiding an encounter with a potentially poisonous biter. The more you know!