The tropical orb-weaver is a fascinating spider from the Eriophora genus, part of the Araneidae family. You’ll often find it in many areas of the United States. Ready to explore some cool facts about this spider? This post has all the details for you!
Size: The females are 0.47 – 0.94 inches (12 – 24 mm) in size, while the males are smaller, 0.35 – 0.51 inches (9 – 13 mm).
Color: The females have reddish-brown legs and cephalothorax. The dorsal part of their abdomen may be brown or grey. At the same time, the ventral portion possesses black triangular markings pointing backward. The males have a grey abdomen with banded legs.
Other Characteristic Features: The abdomen of the tropical orb-weaver males is smaller than their female counterparts. Some of them, particularly those living in Florida, have two humps on their backs, alongside white spots on their abdomen’s dorsal part.
Eggs
The small, oval eggs remain safely enclosed in a sac.
Spiderlings
The juveniles in the Florida region also have white spots on their abdomen like adults. They disperse from their kin after a few molts.
The Web
They have a spiral-shaped web, 19 ft (6 m) built after dark and removed before dawn.
Are Tropical Orb-weaver Spiders Venomous?
Yes, tropical orb-weaver spiders are venomous. However, their venom is mostly harmless to humans and usually just causes minor irritation.
Can Tropical Orb-weaver Spiders Bite?
Yes, tropical orb-weaver spiders can bite, but it’s rare. If they do, it might feel like a bee sting, but reactions vary among individuals.
Ecological Importance and Behavior of Tropical Orb Weaver Spider
Tropical orb-weaver spiders contribute significantly to controlling insect populations. Their nocturnal web-building habits not only facilitate the capture of prey such as small insects but also avoid daytime predators and reduce damage to their webs from birds and larger animals.
Natural Predator: The natural predators of tropical orb-weavers include birds, lizards, and small mammals, which keep their populations in check.
Prey-Predator Dynamics: These spiders exemplify the prey-predator relationship by managing insect populations while simultaneously serving as a food source for their predators, maintaining ecological balance.
Relationship with Humans: Tropical orb-weavers rarely interact with humans, and when they do, it is usually without incident. Bites are uncommon and typically not serious, likened to a bee sting in terms of discomfort.
Quick Facts
Distribution
Florida, Texas, Louisiana, Gulf Coast regions of the United States; Mexico; parts of Central America; Venezuela and Colombia in northern parts of South America
Habitat
Woodlands, orchards, and citrus fruit groves
Diet
Small insects
Lifespan
12 months
Did You Know
At night, these spiders make big webs. They sit in the web during the night. During the day, they hide in a leaf rolled up like a tube, close to their web.
In summary, the tropical orb-weaver spider is an essential component of its ecosystem, serving as a natural pest controller and a participant in the food web.
A tropical orb-weaver spider has notable color differences between sexes. Females typically have reddish-brown legs and cephalothorax with a brown or grey abdomen, while males have a grey abdomen and banded legs. Females also feature black triangular markings on the ventral side of their abdomen, a key identification trait.
No, tropical orb-weaver spiders are not considered dangerous to humans. Although they are venomous, their venom is not medically significant and typically results in only minor, localized irritation. A bite is a rare occurrence, usually happening only when the spider is provoked or pressed against the skin.
Tropical orb-weaver spiders show significant size differences between males and females. An adult female’s body length ranges from 0.47 to 0.94 inches (12–24 mm). The males are considerably smaller, measuring between 0.35 and 0.51 inches (9–13 mm), which is a common trait in this spider family.
Yes, a bite from a tropical orb-weaver is often compared to the sensation of a bee sting. These spiders are not aggressive and bites are uncommon. If a defensive bite does occur, the resulting pain is generally mild and localized, though individual reactions to the venom can vary.
Tropical orb-weavers build their webs at night to align with their nocturnal hunting behavior for catching night-flying insects. This strategy also helps them avoid daytime predators like birds. They typically construct the large web after dark and dismantle it completely before the sun rises the next morning.
Tropical orb-weavers in Florida can exhibit distinct physical features not always present in other populations. Some individuals possess two noticeable humps on their backs. Additionally, it is common for both adult and juvenile spiders in this region to have characteristic white spots on the dorsal side of their abdomens.
The tropical orb-weaver constructs a very large, spiral-shaped orb web characteristic of the Araneidae family. These impressive structures can be quite expansive, sometimes reaching up to 19 feet (6 meters). The web is built after dark to capture prey and is usually taken down before dawn.
Dr Richard J. Pearce (PhD) on August 3, 2020.
Spider Team
