THE EUROPEAN PINE-SHOOT MOTH. 9 



To promote the good work of these parasites specially constructed 

 rearing houses have been erected in Europe during bad outbreaks 

 of the pine moth. The infested twigs are collected in these small 

 houses, which permit the escape of the parasites but not of the 

 moths. 



It is reasonable to suppose that some of the native parasites on 

 some of the native species of Evetria will in time also attack Evetria 

 huoliana in this country — in fact, parasitized larvae have already 

 been observed — but these native parasites can not be relied upon to 

 keep in check their natural hosts, the American pine moths, which 

 sporadically become very abundant and injurious in spite of the 

 parasites, and presumably will be less effective in controlling the 

 newly introduced host. 



METHOD OF CONTROL. 



The larva of the European pine-moth is so effectively protected 

 within the buds that it can not be reached by any insecticide, and the 

 only method of combating it is that used in Europe for more than 

 a hundred A^ears, namely, the pruning and destruction of the in- 

 fested buds and twigs together with the larvae they contain. Such 

 hand picking is practiced every year in the government-controlled 

 forest reserves of Europe. 



This pruning must be done while the insect is within the twigs, 

 and while it may be done throughout the entire year, except during 

 the midsummer months when the insect is in the adult stage, it can 

 be most profitably done in the fall and winter months while the 

 young larvae are yet within the undeveloped buds, because the prun- 

 ing at this time will enable the secondary set of buds to develop in 

 the spring without delay. The only drawback to the collecting of 

 the larvae in the fall and winter is that the infested buds are then 

 less noticeable than in the spring when the injury is further devel- 

 oped. A little practice, however, soon enables instant recognition 

 of the infested buds, even by an unskilled laborer ; the slight exuda- 

 tion of pitch at the base of the bud covering the entrance hole of 

 the larva (PL III) is very characteristic and easily recognized when 

 once known. 



In the spring, when the buds develop into young shoots, the in- 

 jury is very much more apparent, and anybody can then distinguish 

 the infested twigs at a glance. For this reason it is advisable to have 

 the trees gone over again in the spring, so as to remove any infesta- 

 tion which has been overlooked in the fall. In America the work of 

 the larva in the fall (September, October, and November) has pro- 

 gressed far more and is much more easily discovered than is the case 

 in Europe, where the larvae have attained very small proportions and 



