8o INJURIOUS AND USEFUL INSECTS 



laid and hatched in one place. What will happen to the 

 larvEe? Will they become crowded and starved? Any one 

 who has kept vapourer-larvse in captivity knows perfectly 

 well that they will be in no sort of difficulty. They run boldly 

 and pretty fast ; it is easy for them to leave one tree and 

 climb the next. And the next trep is pretty sure to yield them 

 agreeable food. Though they may have been hatched on a 

 rose-tree, they can feed perfectly well on hawthorn, apple-tree, 

 laburnum, acacia, sallow, or oak. Such larvae cannot well be 

 crowded, nor will they starve for want of food. It would be 

 very different if the larvs fed only on one plant, particularly 

 if that one plant grew singly, or a few together. The mullein 

 moth larva, for instance, feeds upon plants which grow only 

 a few together, and is restricted to a single kind of plant, or 

 nearly so. Here the eggs must not be clustered, but scattered. 

 The female must be able to fly from plant to plant, or from 

 one clump to a distant one. This takes time, and the female 

 must accordingly be supported by feeding. Hence she has a 

 well-developed tongue, and can nourish herself upon the 

 nectar of flowers. If we make a list of the moths which have 

 no wings, or only imperfect wings, unable to support the body 

 in the air, and then note the food of their larvae, we shall find 

 that they are either supported during the feeding stage upon 

 the leaves of trees and shrubs, where the supply is practically 

 inexhaustible, or else they feed upon social plants, like grass 

 and heather, or else they are not dainty about their food, and 

 will like what they can get, if they cannot get what they like. 

 The winter moth, the March moth, the umber moth, and 

 others which have no Enghsh names, are well-known 

 examples. Where a promiscuous diet, or the great abund- 

 ance of the food - plant, relieves the female moth from the 

 labour of dispersing her eggs widely, it may be a positive 

 advantage that she should lose her wings. She can then 

 produce more eggs, and her abdomen may swell into a nearly 

 globular egg-bag (as in the vapourer), which no flying insect 

 could carry. The disuse of wings adds also to her safety. 

 She can remain motionless in some hidden corner, safe from 

 all enemies, and only to be discovered by the quick scent of 

 the male moth. No male moth or butterfly is wingless. If 

 the female flies well, the male must fly after her; if she is 

 sedentary, he must seek her out. But in those orders of 



