THE PINE PROCESSIONARY: THE STINGING POWER The Pine Processionary has three costumes: that of infancy, a scanty, ragged fleece, a mixture of black and white; that of middle age, the richest of the three, when the segments deck themselves on their dorsal surface with golden tufts and a mosaic of bare patches, scarlet in colour; and that of maturity, when the rings are cleft by slits which one by one open and close their thick lips, champing and grinding their bristling russet beards and chewing them into little pellets, which are thrown out on the creature’s sides when the bottom of the pocket swells up like a tumour. When wearing this last costume, the caterpillar is very disagreeable to handle, or even to observe at close quarters. I happened, quite unexpectedly, to learn this more thoroughly than I wished. After unsuspectingly passing a whole morning with my insects, stooping over them, magnifying-glass in hand, to examine the working of their slits, I found my forehead and eyelids suffering with redness for twenty-four hours and afflicted with an itching even more painful and persistent than that produced by the sting of a nettle. On seeing me come down to dinner in this sad plight, with my eyes reddened and swollen and my face unrecognizable, the family anxiously enquired what had happened to me and were not reassured until I told them of my mishap. I unhesitatingly attribute my painful experience to the red hairs ground to powder and collected into flakes. My breath sought them out in the open pockets and carried them to my face, which was very near. The unthinking intervention of my hands, which now and again sought to ease the discomfort, merely aggravated the ill by spreading the irritating dust. No, the search for truth on the back of the Processionary is not all sunshine. It was only after a night’s rest that I found myself pretty well recovered, the incident having no further ill effects. Let us continue, however. It is well to substitute premeditated experiments for chance facts. The little pockets of which the dorsal slits form the entrance are encumbered, as I have said, with hairy refuse, either scattered or gathered into flakes. With the point of a paint-brush I collect, when they gape open, a little of their contents and rub it on my wrist or on the inside of my fore-arm. I have not long to wait for the result. Soon the skin turns red and is covered with pale lenticular swellings, similar to those produced by a nettle-sting. Without being very sharp, the pain was extremely unpleasant. By the following day, itching, redness and lenticular swellings had all disappeared. This is the usual sequence of events; but let me not omit to say that the experiment does not always succeed. The efficacy of the fluffy dust appears subject to great variations.