Barn Spider -- Part 1

The common name "Barn Spider" is applied to many different species of spiders in the Family Araneidae (Orb Weavers). Getting a species ID on these spiders from a photo ranges from extremely difficult to totally impossible. Species ID often require a detail examination of the female's genitalia which is well beyond my expertise and inclination.

The spider in the photo above is a female. She is almost twice as large as a male of the same species. She is what I sometimes call a "tidy" spider, meaning that she doesn't leave her web up during the day. Instead, this nocturnal spider rebuilds her web every evening. In the morning, she removes the web by eating it and, thereby, reabsorbing the protein that went into its production. She does leave the primary anchor lines for the web in place. During the day, she stays concealed in a location very near where her web is built.





Above is the under side of the same female spider. The red area at the end of her abdomen (Opisthosoma) are her spinnerets where the web emerges.




Above is a male spider of the same species. Notice the two short appendages emerging from under the spider's "face". There are pedipalps, and are used for sensing the spider's immediate environment, for assisting with eating, and for males, reproduction (specifically sperm deposition). Female spiders also have pedipalps, but if the pedipalps resemble boxing gloves (the tips of the pedipalps are swollen), the spider is an adult male.

Sources and links:
BugGuide Family Araneidae
The Anatomy of Spiders

Barn Spider -- Part 1

Jumping Spider

Jumping Spider (Paraphidippus aurantius)

Jumping spiders do not build conventional webs. Instead, they rely upon their keen eyesight and quick speed to ambush their prey by literally jumping on them. However, when they do jump, jumping spiders string out a single web filament. That way, if they miss, they have a way of climbing back up that strand to their original perch.


Additional photos:

Jumping Spider

Black and Yellow Mud Dauber

Black and Yellow Mud Dauber (Sceliphron caementarium)

Common throughout North America. This female is building a nest on our porch.

BugGuide: "Nests may comprise up to 25 cylindrical cells, which are usually oriented vertically. Typically 6 to 15 prey spiders are placed in each cell, though up to 40 have been recorded. The female may provide the cells with a temporary closure consisting of a thin mud curtain to keep out parasites while she is collecting prey. Once the final prey is placed in the cell, she lays an egg on one of the last prey and seals the cell with a thick mud plug. She may then add more mud to cover the entire cluster of cells."

The species name means "mason, builder of walls" in Latin.

Black and Yellow Mud Dauber