DIAMOND BACK MOTH. 



153 



one, but as it attacks plants which are grown chiefly on small areas near 

 towns, it does not rank as an important pest and has escaped notice. 



Life Hisfort/. — The moth lays small white eg-gs on the leaves ol: the 

 plant on the under side. From these eggs come the caterpillars, slender 

 green creatures, thick in the middle, which feed upon the tissue of the leaf. 



Fig, 170. 

 Diamond Back Moth. {Magnified.) 



not biting it through but eating off the lower surface. These portions of 

 the leaves wither and holes appear in a short time. The caterpillar is 

 about half an inch in length when full grown, the head is small, the body 

 almost devoid of hairs. There are the usual three pairs of legs and five 

 pairs of sucker-feet. The caterpillar lives and feeds for about a fortnight 

 and then constructs a very beautiful cocoon of white silk. The cocoon is 

 very light, of a fine texture, and the green chrysalis is visible within. 

 This is the resting stage, the chrysalis remaining motionless inside for about 

 one week, becoming a little darker in colour. The moth then emerges. It 

 is very small, nearly half an inch long when the wings are folded, with an 

 expanse of two-thirds of an inch across the open wings. The prevailing 

 colour of the wings and body is brownish grey ; the fore-wings have darker 

 spots and a light line along the inner edge. When the fore-wings are 



