V l 2 THIRD ANNUAL REPORT OF 



wild haws, occurring abundantly in the "West, as well as in the East. Of 

 late years it has acquired an appetite for the cultivated apples in 

 some of the Eastern States, where it already does much damage to the 

 apple crop. Yet, strange to say, it has not yet, and may never attack 

 the cultivated apples in the West, and there is more danger that in 

 process of time the more civilized Apple-maggots of the East will 

 spread to the West, than that our haw-feeding maggots which are now 

 among us, will acquire that habit, as a race of them once did in the 

 East. Now no one will argue that if the Apple-maggots of the East 

 were to be exterminated, the maggots in the wild haws would any the 

 sooner attack our cultivated apples ; and in like manner the exter- 

 mination of the lice on our Clinton vines will not cause those on the 

 Wild Frost to any the sooner attack our Concords. 



To give another illustration : — Our White pines have for years 

 been greatly injured by the Pine-leaf Scale (Aspidiotus [M//tilaspis] 

 pinifolicB, Fitch) and I know that this same scale occurs to a slight 

 extent on several other species of the genus, and have good reason 

 to believe that it (or a race of it) is becoming more and more numer- 

 ous on the Scotch pine around. St. Louis. Yet to get rid of this scale 

 I would not hesitate to destroy such White pines as were infested with 

 it, for fear that by such a procedure I should drive the scales on to 

 any other pines ; because I believe that the scales on the Scotch pine 

 for instance, multiply among themselves rather than by the annual 

 transportation of individuals from the White pine, and because the 

 experience of the past teaches that the latter is the only pine which 

 has really suffered injury from this scale. 



Other similar illustrations might be given, but I close by reiter- 

 ating the opinion that there is nothing in the past history of the Grape- 

 leaf Gall-louse to warrant the belief that by destroying the Clinton 

 we shall force it on to those more valuable varieties which it has not 

 hitherto attacked, and that whenever, as is admitted to be the case in 

 the central portion of our State, the Clinton can be replaced by other 

 and better varieties, it will be most wise and judicious to discard it. 

 I have no idea that we shall ever exterminate this louse from our 

 vineyards, because we can never obtain concert of action all over the 

 country, and because it will flourish in a measure on other cultivated 

 varieties of the Cordifolia group. But let each individual act for 

 himself, and I feel satisfied that so far as he follows the advice here 

 given, just so far will he be benefited. 



There are several cannibal and parasitic insects which attack 

 this Gall-louse, but for lack of time to make the proper illustrations, I 

 shall have to leave their consideration to a future Report. 



Figure 39, at the head of this article, represents a leaf covered with 

 galls. Figure 40, (a) represents the winged female ; (b) her foot or 

 tarsus— after Signoret; (c) an enlarged egg ; (d~) the newly hatched 

 gall-inhabiting type, ventral view; 0?) same, dorsal view; (f) 



