INJURIOUS INSECTS OF 1904. 21 



to a pupa (Fig. 8 of colored plate; see also b of Fig. 15). If this 

 cocoon is spun in flour or meal it is matted with the fine par- 

 ticles, as shown in the colored plate. (See also Fig. 9 in text of 

 report.) The pupa is reddish brown, a little less than 1/2 inch 

 long, and about i/io of an inch wide. The last segment of the 

 body of the pupa is provided with a few short hairs. The length 

 of the pupal stage within the cocoon is evidently from ten to 

 twelve days. 



The time elapsing between laying of egg, hatching of same 

 and transformation of larva into a pupa, and the emergence of the 

 moth, is evidently between sixty and seventy days, or an average 

 of nine weeks for one generation. 



Fig. 8. — Egg of Mediterranean Flour Moth, fifty times enlarged. Original. 



The egg, oval in shape, when first laid white and almost smooth, 

 later becoming brownish and wrinkled, is just visible to the naked 

 eye. The eggs hatch in nine or ten days. Two freshly laid eggs, 

 measured in the laboratory, were each .6 millimeters long by 

 .35 millimeters broad, or about 1/42 of an inch long by 1/63 of an 

 inch broad. We figure one of these enlarged twenty-five times on 

 colored plate (Fig. 11). Also same egg in text, Fig. 8, enlarged 

 fifty times. 



Eggs, as zvcU as larva, may be brought into a perfectly clean mill 

 in infested material, tints sotcing the seed of trouble; sacks, bar- 

 rels, a)id seeond-hainl niacJiinery from some infested mill being 

 the chief sources. 



One female which we had under observation in the laboratory 

 at St. Anthony Park began egg laying February 9th, continuing 

 until and including February 14th, five days, laying during that 

 period 247 eggs. Copulation lasts a long time and evidently one 



