298 ]\r.\INE AGRICULTURAL EXrERIMENT STATfON'. I906. 



in such numbers as to murder whole colonies of tussocks in 

 their cocoons. These parasites are however in their turn well 

 attended by parasites so that their aid cannot always be 

 depended upon. 



Remedial Measures. A glance over the life history of the 

 tussock moths gives at once a simple and practical means of 

 combating them. The white egg masses deposited on the 

 cocoons remain on the trees all winter. These are readily 

 seen and can be removed and burned. Cocoons of the tussock 

 not covered with eggs should not be disturbed as they are 

 either the empty cocoons of males or cocoons containing para- 

 sites. If the cocoons are empty they can do no harm and if 

 they contain parasites, these insect enemies of the tussock 

 should be allowed to develop. 



Although the tussocks are two-brooded, this treatment is 

 sufficient, for if the eggs of the winter generation are faith- 

 fully removed there will be no parents for the second or sum- 

 micr brood. The fact that the females cannot fly makes this 

 pest easily controlled locally, for the orchardist need not 

 especially fear his neighbor's infested trees. 



The caterpillars are susceptible to arsenical sprays and this 

 means of combatting them is sometimes necessary where the 

 winter collecting has been neglected or when the tussocks 

 appear in destructive numbers upon shade trees. 



