108 TURNIP, 



rounded, projections ou its front edge ; this band is usually spotted 

 with very small dark points, and in some specimens it is considerably 

 obscured by the ground colour on the hinder margin, leaving the three 

 projecting parts alone conspicuous. The hind wings are narrow and 

 pointed at the apex, have a long fringe, and are of a pale ashy grey 

 colour. The body and legs are brownish grey ; the head and thorax 

 grey or ochreous grey ; antenna white, with some brown or fuscous 

 rings. 



The moths lay their eyi/s for the most part on the under side of the 

 leafage of their food plants, and we see plainly that this is the usual 

 ravaging ground of the caterpillars ; still, they may be present some- 

 times on other parts of the plants. 



The caterpillars, when full grown, are about half an inch long, and 

 peculiar in shape, as they taper slightly towards each extremity ; this 

 is a marked characteristic. The colour is usually a delicate green or 

 apple-green, but this is variable ; in younger state the larva is often 

 yellowish or greyish, with black head. 



When near full growth the head is usually grey or yellowish, 

 marked with small black dots, and the next ring is remarkable for the 

 absence of the two dark patches often found in small caterpillars of 

 allied kinds, and instead has a number of very minute black specks. 

 The rest of the segments have a few black dots, each bearing a bristle, 

 but these cannot be made out without the help of a magnifying glass. 

 Each of the first three segments bears a pair of claw-feet, and there 

 are also four pairs of sucker-feet beneath the body, and another pair 

 (which are very noticeable from being set out somewhat obliquely) at 

 the end of the tail extremity. When alarmed, the caterpillar lets 

 itself down by a thread, and swings in the air till it thinks fit to return 

 by the thread to its previous locality. 



When full fed, which may be in about four weeks, or possibly less, 

 the caterpillars spin their cocoons for the most part on the under sur- 

 face of the leafage of their food plants, or on stems, or amongst seeds, 

 &c., in fact in any convenient place on or near their food plant. 

 These cocoons are somewhat variable in appearance ; sometimes they 

 are a mere open net-work of white threads, sometimes thicker and of 

 a somewhat boat-shaped form. In the former case the colouring of 

 the chrysalis can be distinctly seen through the net ; the characteristic 

 colouring, when mature, is whitish with some black streaks. This was 

 very noticeable in some chrysalids sent me by Mr. Moss, from near 

 Kelvedon, Essex, from which Diamond-back Moths soon after came 

 out. In the early part of their formation the chrysalids may be green 

 or brownish ; there appears to be a good deal of variety in this matter, 

 so far as I can judge from the many specimens which passed through 

 my hands during the past season. 



