Tangled Webs

Actually, not so tangled, and not all spiders spin webs. A spider is guided by instinct in building a web characteristic of its species. The webs are marvels of geometry ... it seems that no matter where we look, mathematics is "hardwired" into the universe.

The orb weaver snacking on the hapless hoverfly in the first three photos looks like a Shamrock Spider (Araneus trifolium). The coloration of this spider is highly variable and some individuals are nearly white. This female had a nest above its web made of rolled up leaves held together with silk. A line connected the redoubt and the web, transmitting vibrations to alert the spider to the presence of prey snared in its net.

Mangora gibberosa ... same spider as in an earlier post.

The same Long Jawed Orb Weaver (Tetragnatha sp.) as in the last post. Despite its limited vision the spider was very well aware of my presence ...

An immature Flower Spider (Misumena sp.), this specimen is approximately one third the size of an adult.

A different species of Crab Spider. It was windy, making it difficult to capture details (especially the eyes), my best guess based on this sole out of focus image is Xysticus sp.

An immature Cross Spider (Araneus diadematus).

The following picture is the ventral view of an adult female Cross Spider. It's hard to judge the scale from a photo ... this spider is actually twice the size of the spider in the two pictures above.

A dorsal view of the adult female Cross Spider seen above.

The next three photos show an adult male Cross Spider. Male spiders deliver their sperm with their pedipalps and the customized organs can clearly be seen in the lateral and dorsal views of the spider.

Female Funnel Weaver Spider, Agelenopsis sp.

This is the smaller Agelenopsis sp. male

A female Nursery Web Spider, Pisaurina mira. Judging by the pale color this one looks like it has molted recently.

Since I caught it in the act of making its web, it's probably safe to say the spider in the next two pictures is an orb weaver. The photos were taken at night against a green background so the quality of the images leaves something to be desired (some of the green was removed and the images sharpened after being downloaded to the hard drive). Some of the orb weavers can be hard to identify even from a good image, based on the information at hand I'm going to go with Larinioides sp. , most likely Larinioides sclopetarius.

The spider in the next picture is a male Larinioides sp., note the large modified pedipalps (he also seems to have misplaced a leg). Male and female spiders appear so different from one another that sometimes it's hard to believe they are the same species.

Experimenting up close with the Digital Camera

A few test shots to determine the digital camera’s ability to resolve detail. A special thanks to Lisa Ford of the By-the-Way Café in Tweed for the loan of her camera, a Canon PowerShot A530.

What looked like a piece of cotton fluff floating in the breeze proved to be a Woolly Aphid. This is the limit of the camera’s resolution, set on auto with the macro enabled.

The focus was adjusted manually to take this photo of a Drone Fly. The wing venation is detailed enough to identify this fly as a Syrphid Fly, the spurious vein between the radius and media and the closed anal cell at the wing margin are clearly visible. In fact the shape of the R5 cell pins down this fly as a member of the genus Eristalis. (Source: Petersons Field Guide to Insects)

Lasius niger, the common black ant found in gardens. The focal distance was set manually to zero. Can’t get any closer than this … I was almost on top of the subject and the nearest and furthest points in the image are out of focus.

A Pine Spittlebug (Aphrophora cribrata), this adult is out of his element. Spittlebugs or froghoppers are normally found in meadows, where the nymphs of this insect produce the spittlelike substance found on plants. The picture was taken in shade from about three inches away.

The Long Jawed Orb Weaver (Tetragnatha sp.) in the following picture was only about an inch long; the photo was taken in the relatively poor light of evening. The focal distance was near zero.

This spider is only an eigth of an inch long. At first I thought it might be a Black and Yellow Argiope spiderling but having done some research on the Internet it looks like this is an adult Mangora gibberosa. The light was good but I’m either getting too close to the subject or the other variables such as film speed were set at a less than optimal value. I had to back off to improve the quality of the image.