RAT AGES OF INSECTS ON FOREST AND FRUIT 

 TREES— KEMEDT. 



The trees in the parks and gardens of tliis city Inning 

 been seriously alTeeted by insects, we sent to Dr. Fitcli 

 some of tlie limbs affected; and the annexed answer 

 gives the remedy for these depredators. 



Hon. B. P. Johnson: 



Dear Sir — The "depredator upon the trees in Al- 

 bany — very extensive" — of which you send mc speci- 

 mens — is a species of scale insect. The oval brown 

 scale is the dried remains of the body of the female, 

 wliich, adhering to the bark, covers and protects her 

 eggs during the winter. When the warmth of the ad- 

 vancing season is about liatching the eggs, a white cot- 

 ton-like substance begins to grow among them under- 

 neath the scale and protrude from one of its ends, ele- 

 vating it from the bark — this cotton serving to protect 

 the tender young ii)sects till tliey become sufficiently 

 robust to endure a full exposure to the atmosphere. 

 The newly hatched insects resemble exceedingly minute 

 lice. Each of these little masses of white cotton which 

 are adhering along the under sides (as I suppose) of 

 the limbs, may now he seen, by the aid of a magnifying 

 glass, to be thronged with these lice, or with eggs not 

 yet hatched. After a while, the lice will forsake this 

 covering and disperse themselves over the bark — par- 

 ticularly the smooth tender bark of the small limbs and 

 twigs — nourishing themselves by puncturing it and suck- 

 ing the sap therefrom. 



All kinds of these scale insects are most pernicious to 

 the trees or other vegetation on which they occur. The 

 apple tree bark louse — the minute oyster shaped scale, 

 so common on our apple trees — is the species with 

 wliich W W Uave had the most experience; and it is alto- 



gether ])robable that any remedy which is effectual for 

 it, will be equally efficacious for all other scale insects, 

 including this now on the Albany trees. In the Memoirs 

 of the old Board of Agriculture of our State, vol. iii. 

 pages 535-539, is copied from the Memoirs of the Cale- 

 donia Horticultural Society, an article by Sir G. S. 

 Mackenzie, on anointing the bark of trees with oil, to 

 destroy insects thereon, alluding particularly to the 

 apple tree bark louse. And in Illinois and Wisconsin, 

 where of late years this insect has been unprecedentedly 

 fiital to their orchards, and where every remedy which 

 could be thought of has been tried, with but indifferent 

 if any success, it is now reported that smearing the 

 bark with oil — the same measure so long ago noticed by 

 Mr. Mackenzie — has been found to be a sovereign cure 

 for this malady. I doubt not but that by it, many of 

 your Albany trees may be saved, which will otherwise 

 perish. Fish oil, or any other kind of oil or grease, 

 thinly applied, everywhere over the bark, so that its 

 glossiness, is merely perceptible, is all that is required. 



Messrs. EUwanger & Barry have also sent me speci- 

 mens of this same insect, as being abundant upon the 

 maples, especially the soft maples, at Rochester. It is, 

 therefore, very common at this time, probably, over a 

 large portion of our State. In former years, I have oc- 

 casionally met with single specimens of this scale on the 

 trees here, in AVashington county. An insect of this 

 same kind occurs upon the maple in I^rope, and is 

 named Lecanium AcerU by entomologists. The fullest 

 account of tills insect which I have seen is in Curtis's 

 British Entomology, where it is stated that " a white 

 flowery-like matter, in which the minute young are to be 

 observed," grows underneath the scales. As it is a fibrous 

 cotton-like matter, not at all pulverulent like flour wbicli 

 our insect grows, I think it is a distinct species from that . 

 of Europe, and have, therefore, named it in my manu- 

 scripts, Lecanium Acericorticis. i. e. the maple bark 

 scale insect. 



Yours truly. ASA FITCH. 



