Spined Micrathena, Spined Orb-Weaver
Micrathena gracilis
Araneidae (Orb-Weavers), Order Araneae
Physical Description
The body features a distinctively shaped, highly rigid, hard abdomen adorned with numerous characteristic conical spines or projections along its margins, giving it a spiky, geometric appearance. The cephalothorax is relatively small and dark.
Size Estimate
Body length typically ranges from 5 to 10 millimeters for females, with males being much smaller, around 3 to 5 millimeters.
Coloration & Markings
Coloration is variable, commonly featuring black, brown, or white patterns, sometimes with yellow or reddish highlights on the abdomen.
Web Type
Builds a classic vertical orb web among trees and shrubs, often incorporating a conspicuous hub where the spider hangs upside down.
Eye Arrangement
Eight eyes arranged in two rows, typical of the orb-weaver family Araneidae, with lateral eyes often paired on tubercles.
Leg Characteristics
Legs are relatively slender, typically dark in color, and adapted for navigating the sticky silken threads of the orb web rather than active ground pursuit.
Venom & Safety Information
Venom Information
Possesses mild venom used exclusively to immobilize small insect prey; it is entirely harmless to humans.
Medical Significance
Medically insignificant. Bites are extremely rare and typically result only in mild, temporary local irritation if the spider is forcefully squeezed against the skin.
Safety Recommendations
No special precautions needed beyond standard garden awareness; simply leave them undisturbed to enjoy their natural pest control benefits.
Habitat & Behavior
Habitat & Range
Widely distributed across the eastern half of North America, favoring wooded areas, forest edges, thickets, and overgrown gardens.
Behavior & Temperament
Docile and non-aggressive towards humans, remaining stationary in the center of its web during the day to wait for flying insect prey.
Diet & Prey
Carnivorous, feeding primarily on small flying insects such as mosquitoes, gnats, flies, and small beetles intercepted by the orb web.
Seasonal Activity
Most active and commonly observed during the warm summer and early autumn months, with adults maturing late in the season.
Description
The Spined Micrathena is one of the forest's most architectural and striking inhabitants. Instantly recognizable by its heavily spined, hard abdomen, this tiny orb-weaver looks almost like a botanical burr or a piece of organic debris hanging in the dappled sunlight. Quietly positioned at the center of its neatly spun web, it serves as a master pest controller in woodland understories and backyard gardens alike.
Key Features
Hard, flattened abdomen studded with prominent conical spines or spikes, paired with a small cephalothorax and typical orb-weaving habits.
Similar Species
Other members of the genus Micrathena, such as Micrathena sagittata (Arrowshaped Micrathena), which features different spine configurations and bright yellow or red coloration.
Life Cycle
Females construct protective silken egg sacs in late summer or autumn attached to nearby twigs or bark, where eggs overwinter until spiderlings hatch in spring.
Ecological Importance
Acts as an effective natural predator of flying insect populations, helping regulate pest species in forest and garden ecosystems while serving as prey for birds and wasps.
Conservation Status
Secure and widespread throughout its native geographic range, facing no major conservation threats.
Interesting Facts
Despite their fierce, armored appearance, they are completely harmless to humans and use their unusual body shape as camouflage to mimic tree thorns or seeds.
Photography Tips
Use a macro lens with a fast shutter speed or steady support. Position yourself to capture the side profile highlighting the abdominal spines against a soft, leafy background.
Identified: 2026-07-30T20:56:05.756401