IV.—Poisonous Spiders and Other Insects.
§ 627. It is probable that all spiders are poisonous; the only species, however, of which we have any definite information relative to their poisonous properties, are Lycosa tarantula and the Latrodectus malmignatus, to which may be added the New Zealand katipo. These spiders possess a poisonous gland connected with their masticatory apparatus, which secretes a clear, oily, bitter acid-reacting fluid; the acidity seems due to formic acid.
Zangrilli has observed several cases of tarantula bite; soon after the occurrence the part bitten is anæsthetic, after a few hours there are convulsive shiverings of the legs, cramps of the muscles, inability to stand, spasm of the pharyngeal muscles, quickening of the pulse, and a three days’ fever, with vomiting of yellow, bilious matter; recovery follows after copious perspiration. In one case there was tetanus, and death on the fourth day. The extraordinary effects attributed to the bite of the tarantula, called tarantism in the Middle Ages, are well detailed by Hecker;[637] this excitement was partly hysterical and partly delirious, and has not been observed in modern times.
[637] “The Epidemics of the Middle Ages,” by J. F. C. Hecker, translated by B. G. Babington, M.D., F.R.S. (The Dancing Mania, chap, ii., &c.)
Dax has described the effects of the bite of the L. malmignatus; it occasioned headache, muscular weakness, pain in the back, cramps, and dyspnœa; the symptoms disappeared after several days.
§ 628. The katipo is a small poisonous spider confined to New Zealand. Mr. W. H. Wright has recorded the case of a person who, in 1865, was bitten by this spider on the shoulder. The part rapidly became swollen, and looked like a large nettle-rash wheal; in an hour the patient could hardly walk, the respiration and circulation were both affected, and there was great muscular prostration; but he recovered in a few hours. In other cases, if the accounts given are to be relied upon, the bite of the spider has produced a chronic illness, accompanied by wasting of the body, followed by death after periods varying from six weeks to three months.[638]