218 INSECTS AFFECTING VEGETATION 



seed, or at their bases under the thin membranes. They may be 

 found either singly or in clusters of twenty to thirty. In the course 

 of a few days the eggs develop into small, active larvae, which at once 

 eat into the grain, devouring the starchy matter, eventually leaving 

 but a thin empty shell. Two, three, or more Iarva3 may be found 

 within a single kernel of corn, but the smaller cereals usually afford 

 food for but one. The length of time of the larval stage is usually 

 four or five weeks, although this varies somewhat 'with the tem- 

 perature. 



When the caterpillar has attained its growth it bores a small 

 hole to the exterior of the kernel to allow of its escape as a moth, and 

 then passes into the pupa state within the seed. The pupa state lasts 

 from a few days to weeks, depending upon the temperature. The 

 entire life cycle from egg to adult is, in this climate, about five weeks. 

 The moths mate soon after emerging from the crysalis, and deposit 

 a laying of eggs. There appears to be no regular time for the ap- 

 pearance of the adults, as all stages may be found at almost any time 

 in the infested grain. This rapid fecundity soon enables them to 

 bring about the destruction of the grain. 



Corn that has not been husked is much freer from the attack of 

 this insect than corn that has been husked or shelled. Grain may 

 be badly infested with larvse and appear to be sound, as the excre- 

 ment from the larvae may fill up the small holes through which they 

 entered; but it may be easily detected when grain is infested from 

 its lighter weight. If a few seeds are thrown into water, the infested 

 ones will not sink as will the sound ones. 



For the treatment of this and the other insects attacking stored 

 grain considered, see the directions for treatment at the close of this 

 bulletin. Since the treatment for the various grain infesting insects 

 is the same in all cases, it is useless to repeat it for each species. 



The Meal Snout-Moth. The meal snout-moth is well known in 

 Europe where it is a great nuisance. In this country it is gaining 

 quite a foothold, and may ultimately become a serious pest. Like 

 the Indian-meal moth and flour moth the larvae of this insect make 

 long tubes, by fastening together small particles of food with silken 

 threads which they secrete. In these tubes they live, feed and go 

 through their transformation. The meal moth feeds upon various 

 cereals, and their products. It is said to even attack straw and hay. 

 The general color is light brown. The fore-wings are marked on 

 their basal and distal parts with patches of dark brown. Across each 

 fore-wing are two wavy, whitish lines. 



The Mediterranean Flour Moth. This insect first became noted 

 as a pest in 1877, when it was found to be doing much damage in a 

 flour mill in Germany. From Germany it spread into Holland and 

 Belgium and later appeared in England. In 1889 it appeared in the 

 Dominion of Canada. It is generally distributed over the United 

 States. The adult is a grayish colored moth having a wing expanse 

 of about one inch. The fore-wings are marked with transverse black 

 lines. The hind-wings are of a dirty white color with a darker 

 border. 



