OF WASHINGTON. 173 



were suggestive of remedies. Among these the great mobility 

 of the larva and the tendency to migration of the imago were 

 most prominent. 



Various methods of checking the ravages have been proposed 

 and practiced. The sweeping and collecting of larvae are found 

 ineffective on account of numbers, and undesirable because 

 enemies are destroyed at the same time ; gathering of eggs, 

 because all over the tree, high up, and difficult to get at ; col 

 lecting pupae, too few on the ground ; breeding of Tachina 

 monachce, too difficult and uncertain. Ditches have been found 

 a good aid to check migration of the larvae and confine it. One 

 of the most ingenious but costly and ineffective propositions has 

 been the steam and electric exhauster, the invention of a 

 socialist, an illustration of which was shown and described. 



The most effective remedy had been demonstrated by a trial 

 over 2,000 acres and at an expenditure of $12,000, including 

 the cutting of infested trees, etc. , to be an application of a glue, 

 to which Mr. Fernow gave the name ' ' Insect I^inie ' ' (from 

 analogy to bird lime). This material has long been used 

 against a number of other insects, among which the gypsy 

 moth. The mobility of the young larvae, which although 

 hatching all along the trunks to the top, are apt in windy or 

 rainy weather, or when the food supply on the tree becomes 

 scant, to let themselves drop, suggested to prevent their re- 

 ascent by applying a band of insect lime, which has been found 

 absolutely effective, the larvae being starved to death. 



Particulars as to the nature, method of application and cost 

 of the remedy were given, and its introduction as a cheap 

 means of protecting orchard and park trees against a number 

 of depredators was suggested. 



In answer to a question by Mr. Howard, Mr. Fernow said 

 that the lime referred to in his communication could be im 

 ported, and if stored in covered barrels would keep for a con 

 siderable period. It would cost about $2 per 200 pounds. 



Mr. Howard called attention to the fact that this and other 

 European moths were subject to the attacks of an immense 

 number of parasites as compared with allied American species, 

 and gave the following data of parasites of several important 

 European moths : Gastropacha neustria, 60 ; Ocneria dispar, 28 ; 

 Psilura monacha, 21 ; Lasiocampa pini, 55 ; &&&Larialeucoma, 

 32. He said also that the great increase of Psilura monacha 



