The spider
soon returned; and an hour afterwards I was much surprised to
find it with its jaws buried in the orifice, through which the
sting is protruded by the living wasp. I drove the spider away
two or three times, but for the next twenty-four hours I
always found it again sucking at the same place. The spider
became much distended by the juices of its prey, which was
many times larger than itself.
I may here just mention, that I found, near St. Fe Bajada,
many large black spiders, with ruby-coloured marks on their
backs, having gregarious habits. The webs were placed
vertically, as is invariably the case with the genus Epeira:
they were separated from each other by a space of about
two feet, but were all attached to certain common lines,
which were of great length, and extended to all parts of
the community. In this manner the tops of some large bushes
were encompassed by the united nets. Azara [10] has described
a gregarious spider in Paraguay, which Walckanaer thinks
must be a Theridion, but probably it is an Epeira, and
perhaps even the same species with mine. I cannot, however,
recollect seeing a central nest as large as a hat, in which,
during autumn, when the spiders die, Azara says the eggs are
deposited. As all the spiders which I saw were of the same
size, they must have been nearly of the same age. This
gregarious habit, in so typical a genus as Epeira, among
insects, which are so bloodthirsty and solitary that even
the two sexes attack each other, is a very singular fact.
In a lofty valley of the Cordillera, near Mendoza, I found
another spider with a singularly-formed web. Strong lines
radiated in a vertical plane from a common centre, where the
insect had its station; but only two of the rays were connected
by a symmetrical mesh-work; so that the net, instead of being,
as is generally the case, circular, consisted of a wedge-shaped
segment. All the webs were similarly constructed.
[1] Venda, the Portuguese name for an inn.
[2] Annales des Sciences Naturelles for 1833.
[3] I have described and named these species in the Annals of
Nat. Hist., vol. xiv. p. 241.
[4] I am greatly indebted to Mr. Waterhouse for his kindness
in naming for me this and many other insects, and giving me
much valuable assistance.
[5] Kirby's Entomology, vol. ii. p. 317.
[6] Mr. Doubleday has lately described (before the Entomological
Society, March 3rd, 1845) a peculiar structure in the wings
of this butterfly, which seems to be the means of its making
its noise.
