CEREAL PESTS INSECTS 



497 



It was first found in Canada in 1889, in California three 

 years later, and by 1895 was reported as injurious in sev- 

 eral eastern states. It has constantly spread, and is 

 now a pest in every milling state of this country and a 

 large part of Mexico. As it is very destructive in Eng- 

 land and Canada, it appears to be well adapted for indoor 

 existence in cool climates. It has no equal, it is stated, 



FIG. 156. The Mediterranean flour moth: a, adult moth; b, adult in 

 its characteristic resting position ; c, larva ; d, pupa ; e, 2 segments of 

 the abdomen. 



as a flour pest, and may well be called " the scourge of the 

 flour mill." In the absence of flour it will attack other 

 cereal products and grain. 



The small white eggs are laid in cracks and accumulations of 

 flour along elevator legs, in spouts, around dust collectors, and in 

 bolters and purifiers. At temperatures of 85 to 90, they hatch in 

 3 days. The caterpillars are whitish or pinkish, inch long, and 

 slightly hairy. They begin at once to spin silken tubes wherever 

 they travel and feed, and by this web-spinning make themselves 

 a great nuisance. They are full grown in about 40 days, when, 

 leaving their silken tubes, they search for proper places to construct 

 their cocoons, and meantime spin a still greater amount of web, 

 This mats the flour or meal together in lumps, clogs the machinery, 

 2* 



