388 REPORT OF THE COMMISSIONER OF AGRICULTURE. 



near by, but later, wlien I found the larvae abundant fully 3 miles from 

 any woods, it seemed improbable that either larvae or adults had — this 

 year at least — been of sylvan habits. 



I found very small larvae in the center of a large wheat-field, much 

 too far from the margin to lead to even the supposition that they had 

 originated outside of the field. 



When I first observed them they were from 4 nuu to 12 mm in length, 

 rather slender, and of a uniform green color. Toward the last of May, 

 as they became more fully developed, there appeared to be two forms, 

 differing somewhat in color and contour of the body. 



One form when full grown was 20 mm in length, tapering very gradu- 

 ally but uniformly from the head posteriorly. Color green, with the 

 exception of two narrow and rather indistinct lines along the back, 

 separated by a narrow line of the same green color as the body, and a 

 wider lateral white line just above the spiracles. Head green, eyes 

 black, and mandibles brown. 



Some individuals of this form became full grown, and on the 29th of 

 May descended a few inches into the earth, and by the 31st had con- 

 structed brown cocoons. As there were many half-grown worms still 

 on the plants in my breeding-cage, and as I afterwards found an imma- 

 ture larva near Oxford, Ind., on grass the 27th of June, I am led to be- 

 lieve that the season of oviposition is somewhat protracted. 



The other form, when full grown, is 21 mm in length, with the thoracic 

 segments — the first in particular — rather robust, the others gradually 

 diminishing posteriorly. Although when young the larvae have a green- 

 ish color, it gradually disappears as they reach maturity, the skin then 

 being of a dingy white and, above, having the appearance of being drawn 

 over a very dark substance beneath, which gives to the larvae a slate- 

 colored cast. It has, like the other, a lateral white stripe, but along 

 the upper margin of this stripe is a row of black spots, one on eacli seg- 

 ment, and one on the neck; a black V-shaped spot at the base of the 

 three anterior legs, and a short, interrupted, transverse black line across 

 the base of each proleg, except the anal. The prologs also have a black 

 ring encircling them at the joint. Head with a faint tinge of yellow, 

 eyes black, mandibles brown. Like the other form they mature from 

 the last of May until about the 20th of June and descend into the earth. 

 Both were quite abundant about Oxford, Ind., but were found much 

 more common on timothy than upon wheat. They do not coil up upon 

 the plant when feeding, but their movements when thus employed are 

 much like those of the army worm (Lencania unipuncta) when similarly 

 engaged. When disturbed they drop to the ground and remain in a 

 coiled position perfectly motionless. 



No adults have yet emerged from their cocoons in the earth, nor will 

 they now be likely to do so before April or May. 



On the 8th of May, before I knew anything of these larvae affecting 

 wheat, I found in a wheat-field near Bloomington, 111., a small brown 

 cocoon which, as I recollect, was like those wliich these larvae construct. 



On opening it I found it contained a green pupa. Both pupa and 

 cocoon were placed in a box, but in my change of location the cocoon 

 was separated and lost, the pupa failing to develop. 



I am confident that it belonged to the same species as these larvae 

 under consideration, and was thrown up by the plow the fall previous 

 in preparing the ground for this year's crop — wheat having been raised 

 on the ground the preceding season. 



Parasites. — While passing through a field of wheat, in May, I saw one 

 of these worms a short distance from me with what appeared to be a 



