128 TRANSFORMATIONS OF INSECTS. 



same species differ very much in their ornamentation and tint- 

 ing. The propriety, then, of separating these kinds of Noctidna 

 is very doubtful. 



The httle dark caterpillars of the Acronycta are very fond 

 of the mosses and lichens which grow upon trees, and upon 

 the walls of our towns, and which are often found on the quays 

 and parapets by the water-side. They usually hide themselves 

 in the day-time in holes and corners, and they finally shut 

 themselves up there, and form their cocoons with silk, moss, and 

 pieces of lichen. One of the commonest of the Noctuma does 

 a great deal of mischief. It belongs to the family of the 

 Noctuida, and is usually seen about the flower beds at dusk on 

 a summer's evening. This little moth, Agrotis scgettun, is called 

 the Reaper by the French. The fore wings are of a greyish 

 brown or fawn colour, and are marked at the base with two 

 undulating lines, and the hind wings are whitish. The males 

 have lighter tints than the females. The moths fly at the end 

 of May, or the beginning of June, their appearance depending 

 upon the warmth of the season. The females generally lay 

 their eggs in little patches on the lower surfaces of such plants 

 as the chicory and beetroot. The caterpillars do not stop 

 upon these leaves, but descend and hide themselves in the 

 ground during the day. They only move during the night- 

 time, and then never trouble the leaves, but enjoy the succulent 

 roots, which they gnaw and perforate just where the stem is 

 united to them. By about the middle of July, the caterpillars 

 have attained their full size, and they then measure an inch 

 to an inch and half in length. Their bodies are smooth and 

 shining, and are sombre coloured. They are ornamented with 

 two rows of black wart-like points surmounted with hair, and 

 there is a general greenish hue over all. Their mandibles are 

 strong and trenchant, and the upper lip has no notch, the 

 mouth being admirably adapted for munching roots. Their 

 hinder or membranous feet are very short, and have a very 

 small hollow in them, surrounded by a hard border, and covered 

 with short hooks. The larva, which gardeners call the grey 

 worm, can crawl over the ground, but its feet are not suited for 

 climbing stems and leaves, or for clasping them. 



