240 INSECTS 



there is a probability of damage already caused, and 

 very great danger of more damage to come. Not that 

 this moth itself has done or is capable of doing any 

 injury. Its mouth parts are such that it is practically 

 incapable of feeding at all, and altogether incapable of 

 feeding on solid tissue of any kind. But it lays its little 

 whitish eggs in the woollen or similar tissue wherever it 

 finds a chance to do so, and from these eggs hatch the 

 little caterpillars whose mouth parts are formed of 

 sharp jaws, quite fitted for cutting the animal fibres 

 among which they live. Almost the first work of the 

 caterpillar after hatching from the egg is to form a 

 little case from the tissue among which it finds itself, 

 held together with silken threads of its own produc- 

 tion; and this case is enlarged from time to time as the 

 insect grows. It is curious how these individuals differ 

 in habit. Sometimes the cases will be made up of fibres 

 of all colors, indifferently put together without pattern 

 or system. At other times, and that is rather the rule, 

 the color first selected will be adhered to, so that in a 

 carpet one pattern may be completely eaten out, while 

 others, of a different color, will be untouched. In my 

 own experience I have observed a very decided prefer- 

 ence for reds where such were obtainable, and in rag 

 and brussels carpets I have seen the red stripes and 

 flowers eaten, while the blue stripes and green leaves 

 were untouched. 



The period of development depends on the tem- 

 perature. In the more northern United States there is 

 only a single brood; in the middle and southern states 

 there are two and in the extreme south and on the 

 Pacific coast there may be more. But the insect is 

 sensitive to cold and does not grow or develop unless 

 the temperature is above 60°, even though it is not 

 killed by a much lower degree. Hence has come the 



