14 THE ARMY- WORM. 



posit their eggs upon young growing wheat-plants. The 

 exact time when this takes place in Minnesota we do not 

 know at present. To prevent the pupae inclosed in thepupa- 

 ria from hatching, early plowing in autumn is necessary. In 

 doing so the stubble containing the insects is plowed under, 

 and the puparia and enclosed insects are in constant 

 contact with the moist earth; this will either destroy 

 their vitality, or the soil will become packed so tightly 

 around them that the ver^^ delicate adult insects can not 

 issue. If the stubble could be burned soon after harvesting 

 the great majority of these injurious insects would be de- 

 stroyed. 



It is still an open question whether the growing of win- 

 ter wheat will increase the danger of introducing the Hessian- 

 flies and of furnishing them the proper conditions for exis- 

 tence. If the insect is single-brooded then the growing of 

 w^inter-wheat will make no difference whatever; if double- 

 brooded we furnish the insects with an opportunity for a 

 second generation. 



Notwithstanding the fact that the parasites have done 

 such wonderful execution and have killed the great majority 

 of the Hessian-flies, every farmer should bear in mind that 

 these insects rapidly increase in numbers, and he should not 

 run the risk of depending upon these small friends but plow 

 his stubble-fields as early and as thoroughly as possible, 

 since in doing so he will employ the only method that can 

 protect him against this pest. Some years ago a female fly, 

 just leaving the puparium, was dissected, &.nd it w^as 

 found that it contained 238 eggs. This shows how rapidly 

 this pest can increase if conditions are at all favorable, 



THE ARMY-WORM. 

 {Leucanla unlpuncta Harv.). 

 Many of the newspapers published in our state contained 

 in the middle of July and the first week in August many very 

 gloomy accounts of a cut-worm which threatened ruin and 

 destruction to every green thing, but which preferred wheat, 

 oats, corn and grasses to other plants. Not only our state 

 but a number of others were equally injured by large armies 

 of these insects. All parts of Minnesota were infested, even 



