Thursday, September 9, 2021

Grass Spider

 Nothing says summer like the endless string of webs left by the grass spider.

As summer reaches its end, days are beginning to get shorter, temperatures are more favorable, and we begin noticing large webs all over our yards. These webs, often glistening with dew in the mornings, are made by one of the most common spiders found throughout North America, the grass spider. The sparkling of the dew-covered webs is truly beautiful, and turns each web into a work of art. There are nearly 1200 known species Worldwide within this family and nearly 120 of them call North America home.

Their sheet-like web spreads out for a foot (or more) in a circular fashion with a distinct funnel-like opening near the center. It is this opening that earned them another common name of funnel web spider. These spiders should not be confused with another spider that goes by a similar name which is the Sydney Funnel Web spider of Australia.

The grass spiders belong to the Araneomorph spiders which are true spiders or modern spiders, whereas the Sydney Funnel Web spider belongs to a family of old-world spiders similar to tarantulas and trapdoor spiders called the Mygalomorph. The Sydney Funnel Web spider has earned a nasty reputation as being one of the deadliest spiders in the world. You will not find these spiders in the United States! Grass spiders are harmless, and not likely to bite unless mishandled. These shy spiders would rather avoid humans and are quick to retreat into their webs. Their fangs are small and not strong enough to puncture skin, except for the elderly and infants. Bites are not known to be serious but should be cleaned to avoid infection should one occur. These spiders will on occasion come into your home, but these indoor visits are rare unlike other species that are more prone to do so.

Grass spiders are medium-sized spiders with a legspan up to 1 1/2 inches. Their color varies from pale yellowish tan with gray markings to reddish-brown with black markings. Their abdomen is gray to black along the margins with a light brown to brownish-red stripe bordered by lighter colored spots. They have very long legs that are banded at the joints. These legs are usually held out in front of the spider at the opening of the funnel.

The females rarely leave the security of their web except to find a new location to build a web. They hide out at the opening of the funnel lying in wait for an unsuspecting insect to crawl across the web. They will run rapidly out of their hiding place and envenomate their quarry and drag it into the funnel to consume at their leisure. The webbing of this genus is not sticky like other spider webs, they instead rely on capturing their prey by using their extremely fast acting venom. 

Males are wanderers and are constantly on the look-out for food and for mates. When a male comes upon a female of his own species he will approach cautiously, after all he does not want to become her next meal. After determining the female is receptive of his attention, he quickly dominates her. By no means is he out of danger, he must make a hasty retreat before she changes her mind and decides he looks scrumptious. Males die shortly after mating, leaving the females to deposit an egg sac under the loose bark of a tree that she will guard until the first frost. Once the first frost comes the female will die often still clinging to the egg sac, making the ultimate sacrifice. Her life for the life of her offspring. Some species of funnel web spiders may live up to two years, but most only live one season.

Many people find their webs unsightly spread across a normally well-manicured lawn and would prefer they weren’t there. Because of the nature of the low-lying web and its tendency to collect debris like leaves and small twigs these webs can begin to look rather unkempt. So how do you get rid of them? There are several things a person can do to help control the number of webs you are dealing with. Make sure any food crumbs, or other sources of human food are picked up. Do not leave pet food out all the time. Mow your lawn more frequently, and trim back bushes, and overgrown vegetation. Eliminate brush piles and using an old broom to remove the webs. By cleaning up the environment the spiders are building the webs in, you are discouraging the prey insects they feed on. If there is no food readily available, the spiders will be encouraged to build somewhere else where there are more resources. Or if you are like me, appreciate the webs for the works of art they are, and rest assured they are helping control insect populations and providing free pest control.