Critter of the Month

A female Golden Silk Spider hangs from her web with the tiny male above her.

L. Chandler --  NPS Photo

Golden Silk Spider
(Nephila Clavipes)

What is that HUGE Spider? Will it eat me?

Those huge spiders you see as you walk along the nature trail are Golden Silk Spiders or Golden Orb Weavers, locally known as "banana spiders". And, no, they will not harm humans.

If you mate, your genes are passed to the next generation.But, if you mate, you may become lunch for your "wife".This is the dilemma faced by the male golden silk spider, more commonly known as the golden orb weaver or calico spider.This colorful spider is common throughout the southeastern United States in woodlands, secondary dunes, and swamps.

At Fort Matanzas National Monument you will see many of these spiders along the nature trail as well as around the visitor center, hanging in the middle of their circular webs which can be as large as three feet (1 meter) across.

The web's support strands, which often span great distances, are spun from a strong, non-sticky, yellow silk, hence the name golden silk spider.The connecting strands, however, are extremely sticky.The spiders prey on any flying insect, such as mosquitoes, unlucky enough to get caught. You may see these spiders repairing their webs early in the morning, for they replace at least half of the web each day.

By August it is the female spider which is most evident.The female's body can reach a length of 1 to 1 ½ inches (2-3 cm). The cephalothorax (head and upper body) is white with three black spots on both sides.The reddish-brown abdomen with white spots makes up about two-thirds of the body length, and grows even larger as eggs develop inside. The long, orange legs have tufts of short, black hair at each joint which help it detect vibrations and locate prey caught in its web.

While the female is a giant, the male's body is only about 1/8 inch (3-4 mm) long.Look for the smaller male clinging to the periphery of the web, staying out of the way of the female in the center, but able to glean hapless insect meals.

During mating, this smaller male approaches the female, climbs onto her massive back, and mates with her.Immediately after mating, she often bites and kills him, using him for food.This extra nourishment gives her the much-needed strength to make her egg sac and lay her eggs. She will then attach the egg sac to the underside of a nearby leaf and guard it until she herself dies that winter.

These beautiful spiders are fun to observe, but like most animals, they will bite if harassed.Although non-poisonous, the bite feels similar to a wasp or hornet sting.Please leave them alone, and they will leave you alone.

Remember that all plants and animals in the park are protected by state and federal laws. Please do not bother them--just observe them from a distance.