Spiders in Guam

Guam is a small country isolated from major land masses. Though maybe small, it is packed with different forms of wildlife. The average daily temperature is at 85 degrees Fahrenheit, which is just perfect for exploring outdoors. If you want to want to visit Guam, make sure you educate yourself on the things that you might encounter, and yes, it includes different types of spider species. These creepy crawlers might make or break your stay in Guam.

Spiders in Guam Identification Chart

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Common Spiders in Guam

Biggest Spiders in Guam

Most Venomous Spiders

Less Venomous Spiders

Common Spiders in Guam

Common House Spider (Parasteatoda tepidariorum)

Scarce Candy-striped Spider (Enoplognatha latimana)

Ogre faced spider (Deinopis spinosa)

Biggest Spiders in Guam

Giant Huntsman Spider (Heteropoda maxima)

Pantropical Huntsman Spider (Heteropoda venatoria)

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Most Venomous Spiders

Cobweb Spiders/Tangle Web Spiders (Theridiidae)

Brown Widow (Latrodectus geometricus) - The Brown Widow Spider is a cool spider that belongs to the cobweb spiders family. Some people know more about its cousin, the Black Widow, but the Brown Widow has its own interesting story.… Continue Reading >

Widow (Latrodectus) - Meet the Latrodectus spiders, often known as true widows! They're part of the cobweb spider family. By July 2017, there were 31 types of them, living everywhere except Antarctica.… Continue Reading >

Sac spiders

Black-Footed Yellow Sac (Cheiracanthium inclusum) - Meet the yellow sac spider! It's a spider that originally came from the Americas. Over time, it's been a part of different spider families, and now it's in the Eutichuridae family.… Continue Reading >

Less Venomous Spiders

Crab Spiders – Thomisidae

Giant crab spider – Olios giganteus

Orb Weavers (Araneidae)

Golden Silk Orb-Weaver (Nephila) - Have you ever seen a spider's web that shines like gold? Meet the Golden Silk Orb-Weaver! With 23 different types living around the world, they're known for their special golden webs.… Continue Reading >

Hawaiian Garden (Argiope appensa) - The Hawaiian garden spider comes from places like Taiwan, Hawaii, Indonesia, and New Guinea. They're part of the orb-weaver spider family, known for their beautiful webs.… Continue Reading >

Frequently Asked Questions

What are the most common spiders found inside houses in Guam?

The most common spiders found inside houses in Guam are the Common House Spider (Parasteatoda tepidariorum) and the Scarce Candy-striped Spider (Enoplognatha latimana). These spiders thrive in the island’s climate and are often found in corners, window frames, and other undisturbed areas where they build webs.

Are there any dangerously venomous spiders in Guam?

Yes, Guam has venomous spiders like those in the Cobweb (Theridiidae) and Sac spider families, but none are considered medically significant for most healthy adults. A bite from these species typically results in localized pain and minor swelling, not requiring extensive medical intervention. Always seek professional medical advice.

What is the biggest spider you can find in Guam?

The biggest spider you can find in Guam is the Giant Huntsman Spider (Heteropoda maxima) or the Pantropical Huntsman Spider (Heteropoda venatoria). These spiders are known for their large leg span rather than a bulky body and are recognized for their incredible speed and preference for hunting insects.

How can you identify a Pantropical Huntsman Spider in Guam?

You can identify a Pantropical Huntsman Spider by its large, flattened body, crab-like leg posture, and typically brownish-gray coloration. They are often found on walls and ceilings inside homes, where they actively hunt for cockroaches and other insects at night instead of building webs to catch prey.

Where are Ogre-faced spiders typically found in Guam?

Ogre-faced spiders (Deinopis spinosa) in Guam are typically found in low vegetation within gardens and forested areas. These nocturnal hunters are known for their unique hunting style, where they cast a net-like web over prey on the ground. During the day, they remain camouflaged on twigs.

Are crab spiders in Guam harmful to humans?

No, crab spiders (Thomisidae family) found in Guam are not considered harmful to humans. While they possess venom to subdue insect prey, it is not potent enough to cause a significant reaction in people. Bites are extremely rare and would likely only result in minor, localized irritation.

Why does Guam have a large variety of spider species?

Guam has a large variety of spider species primarily due to its tropical climate and ecological isolation. The consistent warm temperatures, averaging 85°F, and high humidity create an ideal environment for a diverse insect population, which in turn supports a wide array of predatory spider species year-round.

Spiders in Guam

Common Spiders in Guam

Biggest Spiders in Guam

Most Venomous Spiders