Meet the yellow and black garden spidere

Sep. 03, 2013 @ 09:08 AM

Of all the reactions we get from Windcrest Farm visitors, the two most common comments are in regards to our herd of miniature donkeys ("they are so little!") and the size of our spiders ("they are huge!"). Because we don't spray pesticides, we have a large number of Argiope (ar-GUY-oh-pee) spiders, commonly known as "black and yellow garden spiders" or "writing spiders" to help us with pest control on the farm. Argiope spiders are harmless to humans and help control mosquitoes, flies, gnats, yellow jackets, grasshoppers, aphids, and wasps.

 

Not only is the Argiope large in size, but they are master architects when it comes to building their webs. This garden spider will select a location that is protected from the wind, such as along the eaves of buildings or in tall vegetation. A majority of our spiders at Windcrest prefer the high tunnels and greenhouses. Argiope spiders are "orb" spiders, which means their webs are circular. Like other orb-weavers this garden spider has three claws per foot, one more than most spiders. Orb-weavers use this third claw to help handle the silk threads while spinning. Unlike other orb spiders, the Argiope keeps a very clean and orderly web. The webs are built two to eight feet off the ground and can reach two feet in diameter. The web has a dense zigzag of silk, known as a stabilimentum, in the center which is why these spiders are sometimes referred to as writing spiders. It has been suggested that the Argiope spider is the inspiration for the classic children's novel "Charlotte's Web" by EB White. Every night, the spider consumes the interior part of the web and rebuilds the circular portion each morning with fresh new silk. The spider occupies the center of the web, usually hanging head-down, waiting for its next meal. These spiders are most active in the daytime.

Female Argiope spiders often stay in one place throughout their lifetime and mate once a year. The male Argiope roams in search of a female and builds a small web near or on the female's web. He then courts her by plucking strands on her web. The male has a safety drop line ready just in case the female is not in the mood and attacks him! She lays her eggs at night on a sheet of silky material, then covers them with another layer of silk, then a protective brownish silk. She then uses her legs to form the sheet into a ball with an upturned neck. Egg sacs range from 5/8" to 1" in diameter and she often suspends the egg sac right on her web. Each spider produces from one to four sacs with approximately one thousand eggs inside each. She guards the eggs against predators as long as she is able. However, as the weather cools, she becomes more frail, and dies around the time of the first hard frost.

 

 

Mary Roberts and Ray Tarlton are owners and managers of  Windcrest Farm, a USDA Certified Organic farm and greenhouse in Monroe, NC . Visit www.WindcrestOrganics.com for more information about plants, produce and classes. Facebook: Windcrest Farm Organics