What created this webbing that Anna Sara found in her lawn?
Early one morning the dew was lying thick on the grass and the fog was hanging heavy in the air. It reminded me of the Burl Ives foggy, foggy dew song. As the sun rose and started burning away the dense fog, I noticed some whitish spots in the yard. I rushed outside to investigate. As I rounded the corner of the house, I saw hundreds of what looked like very fine symmetrical sheet-like webs that all had a characteristic black hole in one side. They were all over the yard and in the hay field. It appeared to be some type of invasion that had moved in overnight.
After looking closely at a few, I realized they were the webs of grass spiders belonging to the genus Agelenipsis. This genus of spiders are all funnel web weavers. They have two elongated abdominal spinnerets which they use to weave very fine non-sticky silk webs. The webs are unique in that they are always horizontal and always have a funnel, resembling a black hole at one edge. The web sheet can stretch up to three feet and the funnel can be up to a foot long.
The funnels serve as traps for prey and hiding spots for the spiders. The edges of the web have trip lines which will alert the spider that something or someone has stumbled onto its home. Most spider webs are sticky and adhere to the prey, but webs of grass spiders are not. The geometry of the web is fashioned in such a way that the unlucky visitor will fall into the funnel. The spiders are extremely agile and quick and dart in and out of their hiding spots to pounce on their unlucky meal.
There are 14 species belonging to the genus Agelenopsis, and they are all grass dwellers. They have 8 simple eyes arranged in three rows. Their coloration is yellow-brown or solid brown with darker longitudinal markings on the abdomen. The males are larger than the females. All stages, including the immature grass spiders, are excellent hunters. During the winter, females will occasionally come inside seeking warmth, but the males generally stay outdoors, and do not overwinter in structures. Grass spiders are nocturnal and do most of their hunting at night. They eat small insects, such as ants, small beetles, flies, and other soft-bodied insects.
These spiders are very shy, and many times go undetected unless there is a heavy dew, which makes the webs glisten. The next time there is foggy morning, go out and look around, you may be lucky to see this secretive creature or at least their unique funnel shaped webs.
This week’s question is from Anna Sara Hill, Extension Fruit and Vegetable Agent.
The South Carolina Grower 