Katie's Sightings

Spiders and More!

Sheet web spider webs - Family LinyphiinaeOne afternoon this week, we decided to go for a walk on the local Canyon Creek Trail. When we got there, the leafless shrubs were filled with the webs of sheet web spiders, all beautifully backlit by the sun! They were also filled with sparkling raindrops from the recent storm! Such Beauty!Sheet web spider webs - Family Linyphiinae

Inspired by these spiders and their webs, and in the spirit of Halloween, I'm featuring some of the native species often thought of as "creepy" in this blog! Some of them you definitely wouldn't want to eat or touch, while on the other hand others are quite harmless. All of them are surprisingly fascinating!

Spiders!

Sheet web spider webs & spider (inset) - Family LinyphiinaeSpider webs are pretty incredible structures. Spider silk is a protein fiber that varies in structure (up to 7 different kinds) depending on its use! Most silks have exceptional mechanical properties, including high tensile strength and extensibility. A given weight of silk is five times stronger than the same weight of steel! Some spiders repair their webs at night. Others eat their web and rebuild it daily! Some spiders, such as the Crab Spider, don't build webs at all and rely on camouflage and ambush to catch their prey!

Sheet webs are horizontally spun, flat sheets of silk between tufts of grass or tree branches. These webs are made with individual strands or are woven as a thick sheet of silk, and the spider will also spin separate criss-crossed threads about the sheet. There are over 4, 600 species of sheet web weavers in the world! They are very tiny and don't use sticky thread, but rather entangle and snare prey in their dense webs.Black Widow Spider - Latrodectus hesperus

After seeing the female Black Widow Spider pictured above, I was wondering if all spiders have venom. It turns out that except for two small groups in the arachnid family, all spiders have poison glands and release their secretions into their venom sacs near their chelicerae. However, the majority of spiders do not bite humans and except for a few cases, they are not harmful to the human being or other mammals.

The Black Widow Spiders are very poisonous and should NOT be handled. Their bite can be QUITE painful, but rarely fatal. The female is shiny black with a red hourglass or dashes on its abdomen. Males are brown or gray with red spots on their abdomen!

Spiders are not insects! They are classified in the Kingdom Animalia, the Phylum Arthropoda, the Subphylum Chelicerata, and the Class Arachnida. Spiders are in the Order Araneae. The main differences between insects and spiders are that they have 8 legs (insects have 6 legs) and only 2 body parts (insects have 3 body parts).

Your questions and comments are appreciated. Please feel free to email me at northyubanaturalist@gmail.com. Thanks!