408 TRANSACTIONS OF THE 



are closed by transpiration, when- the plant suffocates and dies» 

 If the weather is too hot or too cold gangrene attacks it, the 

 inner bark immediately turns black and death is inevitable. 

 Honey dew often coagulates on the leaves of forest trees, in con- 

 sequence of a wartn east wind, at a particular stage of their 

 growth, this attracts numerous insects arid they kill the tre#. 

 Long and continuous rain storms induce dropsy on trees, the 

 leaves drop off', the fruit rots, and the tree dies. Blight stops 

 the circulation of the sap which induces the leaves to fall, invites 

 insects, and they destroy the tree. Mildew often coats the leaves 

 of trees with a white powdery substance, induced by hot niglits 

 without dew, and causes their death in a very short time. Flux 

 sometimes ensues when a tree has a superabundance of sap, bursts 

 the bark and bleeds continuously, and unless a remedy is applied 

 the tree dies. h 



After planting, the most important work is to destroy the 

 insects and animals that prey upon our fields and crops; but this 

 destruction must not be indiscriminate. Many wage war upon 

 moles which, in my opinion, should not on any ^account be 

 killed, because in their subterranean excavations they destroy 

 thousands of gr-ubs. The destruction of crows multiplies noxious 

 insects that do inconceivably greater damage to our corn fields 

 than the crows themselves. I never permit them to be killed. 

 The Hessian and 15,000 other insects, so formidable in our wheat 

 fields, may be outwitted by steeping tlie seed and sowing early 

 in well-tilled ground. The few that escape will be devoured by 

 their relentless enemy, the yellow bird. 



The moth Gortyna zea destroys our Indian corn by penetrating 

 the stalk just above the surface of the ground, and the Agrotis 

 Segetum the tender roots. *My remedy is late planting, say the 

 first of June, and high manuring. The wire worm d 'Stroys our 

 grass fields. To prevent its depredations I use lime freely as a 

 top-dressing, from one to two hundred bushels to the acre. The 

 beetle (Areoda lanigera) destroys our hickory trees, the Elaphidion 

 putator our oaks, the Canker worm our elms, the Hylobius pales 

 our pine trees. In thirteen days, last August, thirty-one work- 

 men destryed in a vineyard 41,000,000 of the eggs of a small 

 and very destructive moth, which would have hatched in sixteen 

 days thereafter, and might, if left undisturbed, have produced 

 three or four more generations the same season, to be nourished 

 by the vine. I have seen flies deposit their eggs on the living 

 body of a caterpillar. liinnaeus has said that three or four flie i 

 will devour an ox in as short a time as several lions, by eaeh 



