Cantharides, cantharis , species of insect, of which several types are distinguished. M. Linnaeus places it in the class of insects that have envelopes around their wings and jaws around their mouths. According to the same author, cantharides have antennae in the form of bristles; false, flexible wings; chests lightly plated; and folds in the sides of their abdomens, etc. Syst. Naturae . Mouffet divides the cantharides species into large and small. Those that are the most esteemed as remedies are the large. Their body is thick and elongated. They have transverse stripes, golden in colour, on their wings. They are found among cereal crops. Insect. Theatrum . There are cantharides of various colours. Those used in pharmacy are of a very beautiful green and a shining blue, mingled with gold, with around nine stripes. They are found in summer around Paris, and in many other places, on the leaves of the ash, the rosebush, the poplar, the walnut, the privet etc. , in the open fields and also on cereal crops, where they cause damage. In warm countries like Spain and Italy and the southern provinces of France there are many of these insects. They are very rare in Germany. The cantharides sometimes gather in such great numbers that they appear in the air like a swarm blown by the wind. They are preceded by a disagreeable smell, which they spread widely. This bad smell usually serves as a guide to where one can collect the insects. Cantharides develop from a worm something like a caterpillar. See the detailed descriptions of three kinds of cantharides in the Eph. de l’acad. des cur. de la nat. dec. 2 an. 2 obs. 20 and 21, 22. See Insect.

Powdered cantharides applied to the skin causes ulceration and excites the desire to urinate. It provokes stranguary, thirst, fever, the passing of blood in urine, and emits a stinking, corpse-like smell. It causes the same symptoms when taken internally. It has been observed that it does much harm to the bladder. See examples of these effects in Ephémérides des curieux de la nat. dec. 2 an. 7 obs. 86 in the Recits anat. De Barthol. cent. I hist. 21. Paré writes that when a courtesan gave a young man, whom she had invited to supper, a ragout sprinkled with powdered cantharides, the unfortunate youth was afflicted the next day with priapism and bleeding from the anus, from which he died. Another man suffered a headache and passed dangerous quantities of blood in his urine after taking tobacco mixed with powdered cantharides. Boyle goes further, asserting that people have felt pain at the neck of the bladder, and have found some of the urine-secreting organs to be damaged after merely handling some dried cantharides, from which it follows that cantharides should be numbered among the poisons. To counter this poison Boerhaave prescribes vomits, aqueous liquors, dilutants, oils, emollients and anti-putrescent acids. When used in the urinary tract it is necessary to monitor both the ill-effects and the dose given. Boerhaave believes it useful against rickets, and to stimulate the blood vessels and to soften concretions of the mucus. But in general the use of this remedy, externally and even more internally, requires much care and experience on the doctor’s part.