ii2 OUR HOUSEHOLD INSECTS 



vegetable rubbish that abound in the corners of such 

 places. The rubbish serves it both as food and as 

 materials for strengthening the walls of its tubes on 

 the outside ; on the inside they are smoothly lined with 

 dark grey-brown silk. 



The pertinacity with which the larvae remain in the 

 seclusion of their galleries renders any observations on 

 their habits and life-history a difficult matter, and often 

 information can only be gained at the cost of the lives 

 of some of the specimens, as they are pretty sure to 

 be more or less injured in the endeavour to eject them 

 from their place of shelter. 



The popular name " Grease Moth," and the scientific 

 name pinguinalis (greasy), both refer to habits with 

 which this species has been credited for the last 150 

 years, though considerable doubt has during the last few 

 years been thrown upon them. It has usually been 

 stated that the caterpillar feeds on fat, butter, lard, and 

 other greasy matters; but as the creature is of such 

 retiring habits, it was not easy to make reliable observa- 

 tions on the subject in order to test the accuracy of the 

 statement. It seems,, however, a priori rather unlikely 

 that the food should be of this character, as greasy sub- 

 stances such as those enumerated have an injurious 

 effect on insect life in a way the following considerations 

 will indicate. Insects breathe through their sides, air 

 being admitted through a series of minute openings, the 

 spiracles, which lead into the breathing tubes which run 

 throughout the body ; now, if in any way these spiracles 

 should become clogged, the insect would necessarily be 

 suffocated. But if the caterpillar were to be perpetually 

 eating soft oleaginous substances like butter and lard, 

 and thus to be always living in the midst of grease, it is 

 difficult to understand how it could avoid getting its 



