180 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



1877, but during recent years it has occasioned the loss of many 

 thousands of dollars to mill-owners. It occurs throughout 

 Europe, and is found in Mexico and Chili. It was first recognized 

 in America in 1889, and has since done an increasing amount 

 of damage in California, in New York and Pennsylvania, North 

 Carolina, Alabama, New Mexico, and Colorado, and has become 

 quite generally distributed. " The caterpillars form cylindrical 

 silken tubes in which they feed, and it is in great part their habit 

 of web-spinning that renders them so injurious where they obtain 

 a foothold. Upon attaining full growth the caterpillar leaves 

 its original silken domicile and forms a new web, which becomes 



Fio. 154. The Indian meal-moth (Plodia interpunctella) : a, moth; 6, pupa; 

 c, caterpillar; /, same dorsal view, somewhat enlarged; d, head, and 

 e, first abdominal segment of caterpillar more enlarged. (After Chit- 

 tenden, U. S. Dept. Agr.) 



a cocoon in which to undergo its transformations to pupa and 

 imago. It is while searching for a suitable place for transforma- 

 tion that the insect is most troublesome. The infested flour 

 becomes felted together and lumpy, the machinery becomes 

 clogged, necessitating frequent and prolonged stoppage, and result- 

 ing in a short time in the loss of thousands of dollars in large 

 establishments." 



The life cycle of this insect requires ordinarily about two 

 months, but may be completed in thirty-eight days under the most 

 favorable conditions. The adult moth measures a little less than 

 an inch across the expanded wings. The fore- wings are of a lead- 

 gray color, with transverse black markings, while the hind- 

 wings are dirty whitish, with a darker border. 



The Indian Meal-moth* (Fig. 154) larvae resemble those of 

 the grain-beetles in having a special liking for the embryo of 



* Plodia interpunctella Hbn. Family Pyralididce. 



