HOUSEHOLD INSECTS 245 



furnished with a pair of horny, projecting breathing organs 

 or stigmata and a pair of fleshy filaments (fig. 67). If the 

 food supply is plentiful, the skippers move but little, and 

 often complete their growth in seven to eight days in the 

 cavity in which the mother laid her eggs. When full 

 grown, the skippers continue to feed for a period of seven 

 days, then they move to a dry spot, contract, turn yellow, 

 and gradually change into golden brown pupae. In ten days 

 the flies issue, and thus the life-cycle is completed, in a little 

 over three weeks. If the conditions are unfavourable, 

 owing to a shortage of food or low temperature or both, 

 some or all of the stages may be prolonged, so that five 

 weeks may elapse before the completion of the life-cycle. 

 There are three broods in a year. Although the cheese 

 skipper can scarcely be designated a serious household pest, 

 it is an annoying one, for, given the choice between, say, a 

 Canadian cheese and a Stilton, the discriminating fly would 

 invariably select the latter as the domicile for its offspring. 



THE ARGENTINE ANT 



The Argentine ant, Iridomyrmex humilis (fig. 68), finds 

 a place in these pages, not only on account of the inherent 

 interest of its habits, but also because it is, what may be 

 termed, one of the " coming " pests in the great North 

 American Continent. It is included here amongst the 

 household pests, because it takes front rank as such ; but, 

 at the same time, it is a serious pest to sugar planters and 

 others engaged in agriculture and horticulture. The ant 

 has received its popular name from the fact that Argentina 

 is believed to be one, at least, of the countries in which it is 

 native. At first it was called the " New Orleans ant," for 

 a reason which will be apparent later ; other names which 

 have been suggested and dropped, on account of their 

 inapplicability, are the " crazy ant," the " tropical ant," and 

 the " pernicious ant." 



