In no group are these relations more curious than in the Epeiridae, the constructors of the familiar wheel-like web. Love-making is no trifling matter here. If the female is not in the mood for the advances of the male she will probably regard him as a desirable addition to her larder. Even if his wooing is accepted, he has to beat a precipitate retreat after effecting his purpose, or he may fall a victim to his partner’s hunger.
This strange peril braved by the male in courting the female, which has, as far as is known, no parallel in any other department of the animal kingdom, is frequently mentioned as universal among spiders. It unquestionably exists, and may be verified by any patient observer in the case of the large Garden-spider Epeira diademata, but it has only been observed among certain species of the Epeiridae and Attidae. It will be remembered that in the Epeiridae the males are sometimes absurdly small in comparison with the females, and this diminution of size is thought to have a direct connection with the danger undergone at the mating season. Small active males stand a better chance of escape from ferocious females, so that natural selection has acted in the direction of reducing their size as far as is compatible with the performance of their functions.
Pickard-Cambridge[[303]] cites an extreme case. He says: “The female of Nephila chrysogaster, Walck. (an almost universally distributed tropical Epeirid), measures 2 inches in the length of its body, while that of the male scarcely exceeds ⅒th of an inch, and is less than ¹⁄₁₃₀₀th part of her weight.”
During the mating season the males may be looked for on the borders of the snares of the females. Their action is hesitating and irresolute, as it well may be, and for hours they will linger on the confines of the web, feeling it cautiously with their legs, and apparently trying to ascertain the nature of the welcome likely to be extended to them. If accepted, they accomplish their purpose by applying their palps alternately to the epigyne of their mate. If repulsed, they do their best to make their escape, and wait for a more auspicious moment. Emerton[[304]] says: “In these encounters the males are often injured; they frequently lose some of their legs; and I have seen one, that had only four out of his eight left, still standing up to his work.”
Among the other groups of sedentary spiders the relations between the sexes seem to be more pacific, and there is even some approach to domesticity. Males and females of Linyphia may be found during the mating season living happily together in their irregular snares. The same harmony seems to exist among the Tube-weavers, and Agelena labyrinthica lingers for days unmolested about the web of the female, though it is perhaps hardly correct to say that they have their home in common.
Among the wandering spiders the male usually seeks out the female and leaps on her back, from which position his sperm-laden palps can reach their destination. This is the habit of the Thomisidae or Crab-spiders, and of the quick-running Wolf-spiders, or Lycosidae.
Fig. [199].—Male Astia vittata dancing before the female. (After Peckham.)
The sexual relations of the Leaping-spiders, or Attidae, are so remarkable as to deserve a longer notice. This Family includes the most beautiful and highly ornamented examples of spider life. Their headquarters are the tropics, and their brilliant colouring led Wallace to speak of those he saw in the Malay Archipelago as “perfect gems of beauty.”
Now among these spiders the male is almost always more highly decorated than the female, and Peckham’s observations would lead to the conclusion that the female is influenced by the display of these decorations in the selection of her mate.