通过本讲内容的学习，需要达成以下学习目标/ through  the study of this subject, you need to achieve the following learning objectives:
1- To understand and classify the characteristics and habits of four spiders.

2- To organize the charactersitics and habits of spiders to display the main ideas between them.

3- To create a conceptual knowledge framework to connect ideas and sub-ideas between spiders.

五年及/ five year classes

Species

There are five species of widow spiders in United States; Red widow, Latrodectus bishopi;Brown widow, L.geometricus; Western black widow, L. hesperus; Southern black widow, L. mactans, and Northern black widow, L.variolus. Both are characterized by a similar body shape, reclusive habit, and irregular cobwebs

General identification

Like all spiders, the widow spiders (Red widow, Brown widow, Western black widow, Southern black widow and Northern black widow) have two main body parts, the cephalothorax (the body part to which the legs attach) and abdomen. The cephalothorax bears the head and legs. The abdomen is much larger than the cephalothorax. The spinnerets, or silk and web making appendages, are attached to the rear end of the abdomen. On widow spiders, the spinnerets look like a cluster of small cones.

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