spiked+micrathena+spider

spiked micrathena spider

//Micrathena gracilis// is a spider in the family Araneidae (orb-weavers), commonly known as the Spined Micrathena. This spider spins a moderately large (may be an inch or more across), very tightly coiled web, often in wooded or brushy areas. It is completely harmless to humans.

The only web-building members of the species are the females. They exhibit a bulbous abdomen with a total of ten spines. Males exhibit a fair amount of sexual amorphism. They tend to be around only half the size of the females. Also, they have fewer spines, a flatter abdomen, and a slighter lighter tone. Although males can produce silk, they mostly use it in the mating ritual, which frequently also proves fatal.

Micrathena gracilis hatches in the spring, the image of an adult. After the summer's growth, the female lays eggs in a sack. These remain relatively dormant through the winter months. The general life span is one year in length.

http://www.cirrusimage.com/spider_micrathena.htm

Description
This spider belongs to the family of spiders that spin their webs in spirals - the orb weavers. The Arrowshaped Micrathena hangs in the center of its orb web and can be mistaken for a bit of wood, bark, or leaf. The male spider is 1/4 inch long and the female is only slightly larger, up to 3/8 inch long. The brightly colored abdomen is elevated and covered with pairs of pointed spines (the males lack spines). It has an enlarged pair of spines toward the rear of the abdomen that give this spider its arrowhead shape

Habitat
The Arrowshaped Micrathena is found in the Eastern United States and as far west as Nebraska. It is usually found hanging in its web in woodlands or in gardens. Sometimes it will weave a short zigzag band to strengthen its web above the central orb hole.

Food
This spider feeds on small flying insects that it catches in its web.

Defense
The spines on the abdomen of the Arrowshaped Micrathena serve as a kind of armor to protect it from predators such as birds, lizards, flying insects, or other animals. Despite its armor, the Arrowshaped Micrathena often falls victim to the mud dauber wasp. This wasp will paralyze the spider by stinging it and then encasing the spider in one of the chambers of its mud nest.

http://www.spiderroom.info/va_arrowshaped.html

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