Tropical Orb-Weaver, Tropical Tent-Web Spider
Eriophora ravilla
Araneidae (Orb-Weavers), Order Araneae. Key family characteristics include the construction of vertical circular orb webs, eight similar-sized eyes in a compact cluster, and robust bodies suited for weaving.
Physical Description
The spider has a massive, bulbous, rounded abdomen and a smaller, heavily armored cephalothorax. The body features prominent spiny projections and tubercles, particularly along the legs and around the margins of the abdomen, giving it a rugged, textured appearance characteristic of mature females.
Size Estimate
Body length ranges from 15 to 25 mm for females, with a leg span reaching up to 50 mm. This specimen is a robust, fully mature female.
Coloration & Markings
Base coloration ranges from reddish-brown to tan or light orange, blending with autumn foliage or bark. Distinctive markings include a jagged, white or light-colored cross-like or folium pattern on the dorsal surface of the abdomen, accompanied by scattered dark spots and tubercles.
Web Type
Constructs large, vertical orb webs typically measuring up to a meter or more in diameter. The web is usually built between trees, shrubs, or garden structures at dusk and often taken down or consumed at dawn.
Eye Arrangement
Eight eyes arranged in two rows on a raised tubercle on the anterior cephalothorax, consisting of four central median eyes and two lateral pairs, typical of the orb-weaver family Araneidae.
Leg Characteristics
Long, thick legs heavily adorned with prominent spines, tubercles, and distinct banding patterns. The legs are exceptionally spiny, which helps deter predators and provides grip in the web.
Venom & Safety Information
Venom Information
Contains neurotoxic venom typical of orb-weavers, which is specialized for subduing invertebrate prey rapidly. It poses no chemical threat to humans.
Medical Significance
Harmless to humans. Bites are extremely rare, usually only occurring if the spider is squeezed or trapped against the skin, resulting in mild, localized pain and minor swelling similar to a mosquito bite.
Safety Recommendations
No special safety measures required as they are harmless. If found inside a home, gently guide the spider into a container using a piece of card and release it outdoors into a garden or wooded area.
Habitat & Behavior
Habitat & Range
Found throughout the southeastern United States, Central America, and parts of South America. Prefers humid tropical and subtropical habitats, gardens, forest edges, and wooded areas, often resting quietly among foliage during the day.
Behavior & Temperament
Docile and non-aggressive. Spends daylight hours resting motionless on foliage near the web or hidden within a retreat leaf, becoming active at night to maintain and construct its orb web.
Diet & Prey
Feeds primarily on flying insects such as moths, beetles, mosquitoes, and flies that become ensnared in its sticky vertical orb web.
Seasonal Activity
Most active and commonly observed during late summer and autumn when females reach maximum adult size and construct their prominent webs.
Description
The Tropical Orb-Weaver is a master architect of the night, recognized by its large, rounded, spiny abdomen and reddish-brown hues. During the day, it blends seamlessly into surrounding foliage, only to construct massive, intricate geometric webs after dark. As a beneficial predator, it helps naturally regulate flying insect populations while adding fascinating biological wonder to gardens and woodlands.
Key Features
Large, bulbous, highly textured abdomen with prominent spiny tubercles, a jagged light dorsal marking resembling a cross or leaf outline, and heavily spined, banded legs.
Similar Species
Other large orb-weavers such as Neoscona crucifera (Spotted Orb-Weaver) and Araneus diadematus (Cross Orb-Weaver), distinguished primarily by subtle variations in abdominal patterns, spine distribution, and geographic range.
Life Cycle
Females construct silken egg sacs containing hundreds of eggs in late autumn, which overwinter in sheltered locations. Spiderlings hatch in spring, disperse via ballooning, and mature through successive molting stages by late summer.
Ecological Importance
Serves as an essential natural predator of nocturnal flying insects, helping control garden pests, while also serving as a vital food source for birds, bats, and small mammals.
Conservation Status
Not evaluated by the IUCN, but populations are widespread, stable, and generally abundant throughout their natural geographic range.
Interesting Facts
Eriophora ravilla is famous for its color polymorphism; individuals can change or display drastically different color phases ranging from bright yellow and green to deep reddish-brown and white across different molts.
Photography Tips
Photograph during dusk or early morning when the spider is active on its web, or use a macro lens with a diffuser in daylight to capture the intricate details of the spiny abdomen and leg tubercles against natural green foliage.
Identified: 2026-09-24T09:43:31.294713