One of our well known spiders found in landscapes is the Yellow and black garden spider, Argiope aurantia. Most people will recognize this beautiful spider that rests in a large web with a zigzag web pattern in the middle called a stablementum. A wide variety of insects will be caught in the web throughout the summer, with many prey larger than the spider itself. The Yellow and black orb weaver is just one of our beneficial spiders in landscapes.
Garden spider waiting for a meal. Photo by Beth Bolles, UF IFAS Extension Escambia County.
As fall approaches each female garden spider leaves us a wonderful gift in the garden. She will create a very distintive egg sac that can be hidden in plants or hang in the corner of a porch. The sac is brown and pear shaped, supported by strands of web attached to branches or structures. Hundreds of eggs are inside and although they hatch in late fall, the spiderlings will stay in the sac until the spring. A large number of spiderlings will not survive due to predation and other factors, but a few will continue development to adorn your garden in the following season.
Egg sacs of the Yellow and black garden spider in a rosemary. Photo by Beth Bolles, UF IFAS Extension Escambia County.
If you did have a garden spider in your landscape this summer, just be a little more careful when maintaining plants. You don’t want to accidently remove the overwintering egg sac. Although this large spider can be startling for many people, they are not aggressive and are considered beneficial in the garden.
A number of years ago a gentleman told me about an orb weaver spider that was living by his front door. He said that it had been there for about two months and that it was interesting to watch the construction of the intricate “bug catching” web. However, he explained that he had a number of people coming to visit and he wanted to know about relocating the spider to his backyard.
Golden silk orb-weaver spider. Photo credit: UF/IFAS
These types of spiders typically construct their webs in an area and stay in that location based on the environment. Many of the orb weaver spiders rely on flying insects and usually construct their webs several feet or more above the ground. This is a good height to capture many flying insects. As a result, there needs to be items within a reasonable distance to attach and place the web. If a spider is randomly relocated, there may be nothing in reasonable distance to support a web. There needs to be at least a couple of tall shrubs or tree trunks for the spider to construct a web in-between the plants several feet above ground level. It needs to be in an area with limited people movement to prevent disturbance by people walking into it. It needs to be in a location with enough flying insect activity to satisfy the spider. If it’s not the right location, the spider may move back to another location, perhaps the front door area.
Webs built by these types of spiders can be quite large and may be suspended several feet or more above the ground. Some people become annoyed and/or frightened as they accidentally come in contact with these webs, brushing the webs from their face and arms. I’m sure the spider becomes annoyed, too, having to rebuild its web.
Despite their size, orb weaver spiders pose little threat to people. They’re considered beneficial because they feed on a wide range of flying insects. They usually construct webs in relatively sunny, open areas with little wind.
Even though these spiders are beneficial, many people don’t like spiders. If you choose to control spiders in and around your home, keep in mind it’s unwise and impractical, if not impossible, to control all spiders.
By the way, the gentleman concerned about the spider decided to leave the spider at the front door area. He posted a sign next to the web in hopes that his guests would steer clear of the web. He offered his garage entrance to those frightened by the spider.
For more information on orb weaver spiders, visit the below UF/IFAS Extension website.
Recently, Okaloosa County Commissioner Carolyn Ketchel mentioned to me that she had seen brown widow spiders in parts of Okaloosa County on multiple occasions. Concerned about this and to provide better awareness of this spider, she asked if I could write an article about this spider.
Most people seem to be aware of the black widow spider but many people have never heard of the brown widow spider.
Brown Widow spider. UF/IFAS Photo: Thomas Wright
There are four widow spiders found in Florida. They include the southern black widow, northern black widow, red widow and brown widow. All are highly venomous but they are also timid. Bites usually occur when the spider can’t easily get away and becomes unintentionally caught between a person’s skin and clothes or when a person is reaching for something where a widow spider is hiding. A UF/IFAS Extension publication on brown widow spiders states, “According to Dr. G.B. Edwards, an arachnologist with the Florida State Collection of Arthropods in Gainesville, the brown widow venom is twice as potent as black widow venom. However, they do not inject as much venom as a black widow, are very timid, and do not defend their web.”
Widow spiders are about 1½ inches long with legs extended. All have rounded, relatively large abdomens. Both of the black widows are shiny black in color. The southern black widow possesses the classic red hourglass marking on the underside of its abdomen. While the northern black widow has two reddish triangles that resemble an hourglass on the underside of its abdomen and red spots in a row along the middle of its back. The red widow’s head, thorax and legs are reddish orange. Its abdomen is black and lacks a complete hourglass but there may be one or two red spots on the abdomen. The brown widow may be gray, light brown or black in color with an orange or yellowish-red hourglass marking on the underside of its abdomen.
Brown widow egg sac. Photo credits: Carolyn Ketchel
The brown widow egg sac looks different as compared to the other widow spiders. They are less than ½ inch in diameter with pointed white silk spikes on the surface which are not present on egg sacs of the other widow spiders. The egg sacs of the other widow spiders have smooth surfaces.
The brown widow likes to build its web in secluded, protected areas such as empty plant containers, mail boxes, building entry way corners, under eaves and inside of old tires.
More information on widow spiders is available from the UF/IFAS Extension Office in your County or from the below links.
Spiders can act as a great bio-control for Florida Gardens. Watch this video by UF/IFAS Entomologist and spider expert Lisa Taylor to learn why having spiders around is a great way to keep pests in check.
The year’s mild winter and frequent rain showers have created lush lawns and gardens with an abundance of insects. As a result, we are seeing many predator arthropods taking advantage of the available feast. One of the morning interesting creatures in the garden is the spiny orb weaver spider (Gasteracantha cancriformis) that has an interesting body shape.
Spiny orb weavers are common spiders in landscapes that might not be noticed since they are much smaller than the Yellow garden spider (Argiope aurantia) and the Golden silk spider (Nephila clavipes). Once viewed, the spiny orb weaver will catch your attention because it’s abdomen has six ‘spines’ or points that extend out. Spiders also have a mix of yellow, white, red, or black marking on the abdomen.
Spiny orb weaver in the center of the web waiting for a meal. Photo by Beth Bolles
Although spiders are small, the webs which are common amongst shrubs, trees, and edges of woods become quite substantial in the fall. There may be up to 30 spirals that extend out with the spider situated in the center. You may unexpectedly encounter a web when walking through the garden or mowing around trees and shrubs. There is no worry if a spider accidently gets on you as bites are not common and not considered serious.
Spider working on her web. Photo by Beth Bolles
Some may refer to the spiny orb weaver as a crab spider based on its shape, but it is a web building where the true crab spiders are active hunters often found resting on flowers in order to ambush a meal.
Enjoy our fall weather and look out for this beneficial spider in your landscape.
