The Bolas Spider Mastophora (Araneidae)
Although it belongs to the orb weaver family Araneidae, the Bolas spider has gone one stage further in the development of the orb we--by not using it at all. Specializing in catching the male of a particular species of moth, the spider lures them by imitating the scent of a female during mating time. Bolas spiders spin a single line beaded with one to several sticky droplets. As a male moth approaches, lured by the scent, the spider throws the line or swings it like a lasso. If its aim is good and the glue makes contact, the moth is caught and held as the spider hauls it upward.
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Water Spiders Argyroneta aquatica (Argyronetidae)
Water spiders are found in slow-moving fresh water in Europe and Asia. They spend their entire lives underwater, building a bell-shaped structure of silk that is made with a silken sheet tied to water plants. The diving bell is filled with air brought from the surface in a bubble surrounding the spider’s body. The spider creates an air bubble by pushing its abdomen up through the surface tension of the water. Any insects or crustaceans that come near are quickly pounced on.
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They are carried to the bell to be eaten, because of the way spiders pre-digest their food.
Water spiders trail a silk thread behind them as they swim through the water, although it is not used to catch prey. Interestingly, males are larger than females, which is uncommon in spiders. Water spiders can survive winters sealed in an empty snail shell or silk cell. One large air bubble is sufficient for the four months of winter, when the spider’s metabolism slows.
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