Fig. 2.—Caltrops and Spines of Caterpillars.
Those who have taken up the study of butterflies and moths, will do well to be careful in handling hairy caterpillars, especially those of the family known as the Bombyces. Some of the members of this family, such as the Fox-moth and the Brown and Gold-tailed moths, when in the caterpillar stage are thickly clothed with long stiff hairs, and these, if the creature be handled, pierce the skin and break off. In consequence very painful itching and irritation is set up. But this is nothing to the pain caused by the caterpillars of the wonderful 'Procession moth' (fig. [1]). In these caterpillars the poison hairs are very loosely attached to the body, and studded with exceedingly fine hooks that curve inwards, as may be seen in the diagram of a magnified portion of one of the spines (fig. [2], d and e). Partly by adhering to the skin, and partly by means of a very fine dust with which they are covered, these hairs set up a very violent inflammation on the skin of men and animals, which is hard to get rid of. On this account, moreover, the neighbourhood of the nests of these larvæ is dangerous, for the surrounding air is filled with the hairs and dust borne about by the wind. These are thus inhaled, and give rise to internal inflammation and swellings which have sometimes caused death.
One of the most remarkable of all hairy caterpillars is that of an American species (fig. [3]), burdened by scientific men with the terrible name—Megalopyga! The shorter hairs are poisonous.
Fig. 3.—Megalopyga Caterpillar.
The caterpillar of our British 'Festoon moth' belongs to a very remarkable family indeed. All the caterpillars of this group, which is found in many parts of the world, are very slug-like in form, and many have an evil reputation as poisoners, though our English species is happily innocent. A small Australian species has the body armed with slight reddish knobs, four in the front and four in the hind part of the body. These knobs can be opened at will, and from them slight rays or bunches of stings of a yellow colour are thrust out. The wounds which these darts inflict are very painful. Of one Indian species a collector records that 'the caterpillar stung with such horrible pain that I sat in the room almost sick with it, and unable to keep the tears from running down my cheeks, for more than two hours, applying ammonia all the time.'