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Order of the Month
Araneae Fun
Facts
by John Jackman
* Only three or four families of spiders make orb webs - the flat webs with spiral strands around rays or radii.
* Spiders only ingest liquid food. Spiders spit digestive fluids on the prey and then suck up the juices to eat. They may manipulate the prey with their chelicerae and pedipalps so the prey may become a mass of body parts in the process.
* Drag lines are made by jumping spiders. These spiders leap off of a surface and can pull themselves back up on a single strand of silk. As the spider climbs the web strand they eat the silk and later use it to produce more silk. The Spiderman character performs many of the feats of jumping spiders!
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* Orb webs are built one strand at a time. Spiders span an open area by letting a strand of silk which has a sticky end blow in the wind across the opening. When it catches another surface the spider pulls the silk tight and attaches it to the surface. Another approach some orb weavers us is to crawl over to the second site to put up a drag line. Once the drag line is in place the spider move to the center of the line and drops down on a silk strand. After more radii strands are added them the orb weaving starts. The spider starts at the center of the radii and crawls in a spiral leaving a strand behind. The distance from the last strand is measured to keep the spiral evenly spaced.
* Spiders seldom bite people unless they are grabbed, cornered or threatened. Actually, most spiders run when threatened so it is difficult to get a spider bite. Most spider bites occur when someone rolls onto them in night, slaps one on their neck, steps on one barefoot, or in other such situations.
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* The main spiders that cause concern for human safety are widow spiders and recluse spiders. Several species of each are present in Texas and all should be considered hazardous. There are only a few other spider species that have reports of bites which have caused serious medical concern in the United States.
* Most spiders have six or eight eyes. A few spiders have four, two or zero eyes. Spiders with less than six eyes are usually found in caves or other are very small. No spiders in the U. S. have more than eight eyes.
* Spiders have eight legs. All of them also have a pair of pedipalps near the mouth that appear like small legs. Pedipalps are used much like antennae to sense the surroundings and to manipulate food. Mature males spiders have a special apparatus on the end of the pedipalps that is used to store sperm temporarily during mating. Structures on the male pedipalps must fit into the epigynum of the female to complete the transfer of sperm.