THE BOX-ELDER LEAF-ROLLER IN 1896. 31 



safest way, however, is to destroy their homes, not our 

 houses, but the shelters in them that they prefer to occupy. 

 The brick pavement under stoves should be laid in such a 

 manner that the insects can not force their way underneath 

 which they are so well enabled to do, their legs being formed 

 for digging. All the cracks should be hermetically sealed, 

 and especial attention should be paid to the foot-boards 

 which, as a general rule, do not fit tightly against the walls. 

 The space between them and the walls should be filled in and 

 a close fit should be made by means of putty. By taking 

 away their breeding-places and homes we soon force them to 

 leave our houses ; the^^ are very apt, however, to migrate to 

 more hospitable people. 



The illustration (fig. 18) shows the adult insects as well 

 as a young cricket. The insect is of a light leather-brown 

 color and marked with darker brown spots upon the head 

 and two triangular brown spots and a band upon the thorax. 

 Head and legs are lighter colored. As can be seen the male 

 is distinguished by the musical instrument it carries on its 

 back while the female possesses a long ovipositor. 



THE BOX-ELDER LEAF-ROLLER IN 1896. 

 {Cacoicia semiferana Walk.). 



These leafrollers (illustrated on plate XV) which caused 

 so much damage to box-elder trees in St. Paul in 1895, could 

 again be found in considerable numbers during the early part 

 of the year, but as the rainy weather in spring and early 

 summer was decidedly to their disadvantage and to the ben- 

 efit of the trees no very serious damage was done. Many 

 of the trees were attacked, but the foliage had obtained an 

 early start and as the worms Avere forced to eat wet foliage 

 they grew but slowly. Still, if the parasites in 1895 had not 

 greatly reduced the numbers of these worms most trees would 

 again have been denuded. 



Some experiments with Paris green were carried on to 

 demonstrate the value of this poison against the insect in 

 question and experiments with "Raupenleim" (caterpillar- 

 glue) were also made to test its value against insects of this 

 nature. 



