INSECTS AFFECTING CEREALS, ETC. 



110 



e 



Fig. 50. — Plodia interpunctella : a, moth: b, chrysalis; c, caterpil- 

 lar, lateral view; /, dorsal view — somewhat enlarged; d, head, 

 and e, first abdominal segment of caterpillar— more enlarged (au- 

 thor's illustration). 



the illustration (fig. 56, a). The outer two-thirds of the fore-wings are 

 reddish brown, with ;i coppery luster; the iuner portion and the hind- 

 wings are light dirty 

 grayish. The larva. 

 or caterpillar, shown 

 ate, tf, e, and/, meas- 

 ures when full grown 

 about halt an inch and 

 varies in color, being 

 whitish, with light 

 rose, yellowish or 

 greenish tints. The 

 pnpa (6)is light brown 

 in color. 



The eggs are minute and white, and are deposited, to the nnmber of 

 350, singly and in groups of from three to a dozen or more, upon 

 whatever substance the female may see fit to select for the sustenance 

 of her offspring. In four or more days they hatch, and in four or more 

 weeks another brood is produced. In this manner a succession of 

 generations appears which will vary, according to the temperature of 

 the building that the insect inhabits, from four to possibly six or seven 

 a year. 



The caterpillars spin a certain amount of silk as they feed, joining 

 together particles of their food and excrement, and thus injure for food 

 several times the amount of material that they consume. When fully 

 matured they crawl hither and thither, trailing large quantities of their 

 silken threads after them, in their search fbr a suitable place for traus- 

 formation, and finally surround themselves in a cylindrical silken web, 

 in which they change to chrysalids and then to moths.. 



THE MEAL SNOUT-MOTH. 



(Pyralis farinalis Linn.) 



This species in its mature condition is the most attractive of all 

 household insects. It measures across its expanded fore- wings upward 



/A 



■£>. 



Fio. 57 .—Pyralis farinalis : a, adult moth ; l>, larva; <•. papa 



in cocoon twice aatural si/e (original). 



of three-quarters of an inch. Its dark colors are of different shades 



of brown, with reddish reflections: the lighter colors are whitish and 



