no OUR HOUSEHOLD INSECTS 



imperfectly known to entomologists long after the moth 

 had become a most familiar insect. The caterpillar 

 constructs long tubes composed of particles of dust 

 and flour or meal, or whatever its food happens to be, 

 spun toughly together with silk of its own manufacture ; 

 and, protected by these, it easily pursues its depredations 

 without being discovered. But though it may thus 

 escape the vigilance of human eyes, it cannot manage 

 to elude the penetration of the maternal instinct of 

 the ichneumon-flies, which are ever on the watch for 

 the well-nourished bodies of caterpillars in which to 

 deposit their own eggs ; and so even this well-concealed 

 larva has sometimes to succumb to the attacks of Exochus 

 mansuetor, an ichneumon-fly whose maggotlike offspring 

 devour its very vitals. The life of most caterpillars 

 extends over only a few months, or even weeks, but the 

 caterpillar of the meal moth is blessed with greater 

 longevity, for, being hatched in the autumn, it survives 

 the snows of two winters, and does not become a perfect 

 insect till the summer of the second year. It spins a 

 tough white silken cocoon, which fits closely upon the 

 glossy chrysalis within. 



Two other members of this genus are well-known 

 British insects, though they are not to be regarded as 

 house-frequenters. One of them, P. glaucinalis, usually 

 about the same size as the meal moth, or a trifle larger, 

 has glossy, dark, reddish-grey fore- wings, crossed by two 

 delicate yellow lines; the other, P costalis, is much 

 smaller, and is one of the most exquisitely coloured 

 insects we have. It is popularly known as the " Gold 

 Fringe," because the marginal fringes of all the wings 

 are bright golden yellow, a most unusual style of orna- 

 mentation. The ground colour of the wings is a delicate 

 pink, which, especially in the fore pair, is more or less 



