tnu'k-ii,ai'(lon its injuries to green tomatoes are notorious, althougli in 

 tliis work it is aided by a number of other kinds of caterpillars. 



It is a cosmopolitan insect, being now found in virtually every part 

 of the world. It is very common in Illinois, where it is most widely known 

 because of its injuries to green corn in the garden and to field corn, 

 particularly in the southern half of the state. 



Early in spring it feeds on corn leaves, filling them full of holes the 

 size of small shot, and later in the season it enters the tips of the ears, 

 gnawing away the silk and eating out irregular winding channels among 

 the soft kernels, thus often making its way down below the middle of 

 the ear. A single caterpillar does not confine itself to a single ear, but 

 leaves its Mork of destruction to be continued by other insects and by 

 fungi, wliich are likely to follow up its injuries. It bores a round hole 

 through the husk at the side of the ear, and infests others in succession. 

 There are sometimes two or three caterpillars in the same ear, but in that 

 case they are commonh- of different ages. 



There are three annual generations of these caterpillars in the North, 

 and in the South from four to six, besides a series of broods preceding 

 these, which come from a few individuals that pass the winter as adults. 

 The species hibernates in the pupa stage, and emerges to lay eggs in 

 early April. These range from two hundred to five hundred in number 

 for each female, and are shaped like an inverted teacup (see PI. 1\). 

 with the vertical ribs converging towards the apex and broken up by 

 concentric grooves into little knobs. The caterpillars reach their growth 

 in from two to four weeks, and the moths (see PI. IV) appear about two 

 or three weeks later. The first brood of caterpillars in Illinois feeds on 

 the leaves and the tender shoots of corn, the second brood devours the 

 tassel, the silk, and the ear, and the third infests the hardened ear. The 

 fourth and fifth broods, where they occur, all attack various plants, 

 particular'y the cotton-boll in the South. A sixth generation is reported 

 from Texas. The caterpillar enters the earth for pupation to a depth 

 of from two to five inches, where it forms a slender cocoon by lining the 

 end of the burrow with a feAV threads of silk. (See PI. IV.) 



The mastery of this pest in the corn field is still an unsolved prob- 

 lem. It is believed that late fall plowing of corn fields which have been 

 infested by this insect will destroy it in the pupa stage by breaking up 

 its underground shelter and exposing it to the vicissitudes of the weather. 

 It is not often practicable, however, to plow corn ground in fall in Illi- 

 nois, and the effect of such a measure at best can only be to diminish 

 tlie number of moths in the neighborhood the following vear 



