CALOCAMPA EXOLETA.
(Sword-Grass Moth.)
This moth is an English species. It measures in expanse between two and three inches, and is of a soft violet grey tinge, the fore-wings having a variety of brown markings. The caterpillar feeds on the Euphorbia, and has been found gregariously with the Tithymali on that plant. It is met with, however, on peas and potatoes, and can be reared on the leaves of any of these plants. The larva is bright green, with two lines of black and white spots down each side of the back. These are bordered by a yellow stripe (sometimes, however, absent), and it has a broken red line on each side. The caterpillar attains a length of about three inches. Some were kept in the same breeding cage with the Tithymali, but their habits were entirely different. When the Exoleta caterpillar ceased to feed, it did not immediately attain the pupa state, but was restless and lively, remaining as a caterpillar from six to eight weeks, gradually shrinking and losing its colour, until it turned to the pupa. It made a fragile shell of fine earth, oval in form, and buried itself a short distance under the surface. Full-sized caterpillars, taken on the 20th of March, ceased feeding and turned to the pupa state from the 1st to the 20th of May, emerging to the moth on the 15th of June. In some specimens the process of turning to the pupa took place on the journey to England in a box, the caterpillars being covered lightly with cotton-wool.