CATALOGUE OF INSECTS. 25 



but, practically, it has been found that fish-oil, combined or saponi- 

 fied with potash, makes the most effective insecticide. 

 A good fish oil soap may be made as follows : 



Concentrated potash lye 3^ pounds. 



Water, 8 gallons. 



Fish oil 1 gallon. 



Dissolve the lye in boiling water and to the boiling solution add 

 the oil ; boil for two and one-half hours, adding water slowly to make 

 up loss in boiling, and then allow to cool. 



Farmers with a proper outfit claim that this soap can be made for 

 about one cent per lb., but it is difficult to obtain a uniform product. 



Good fish, or so-called "whale oil," soaps, are made at from 3^ to 

 5 cts. per lb., according to quantity, by Leggett & Brother, Pearl St., 

 New York (Anchor Brand), and James Good, South Randolph St., 

 Philadelphia (Potash No. 3). Of the latter several thousand pounds 

 are annually used in New Jersey with general satisfaction. 



This soap may be used against plant lice and sucking insects gen- 

 erally, in summer, at the rate of 1 lb. in from 4 to 6 gallons of water. 

 Against the San Jose or pernicious scale iu winter it is used 2 lbs. in 

 1 gallon of water. 



As a protection against borers, the stronger soap mixture may be 

 painted on tree trunks in early summer, and renewed from time to 

 time as needed. Carbolic acid, at the rate of an ounce to 1 gallon of 

 soap, adds to its effectiveness as a repellant, and lime, sufficient to 

 whiten, makes the wash more visible and somewhat more lasting. 

 One of the arsenites ma}' also be added and will occasionally kill a 

 borer, where the other materials failed to prevent the adult from 

 ovipositing. 



Lime is often useful as an insecticide, and yet more generally as a 

 repellant. Freely used as a whitewash on trees, fences, out-houses, 

 etc., it reduces the number of hiding places for insects, for none of 

 them like lime and few care to remain on a white surface, which 

 renders them conspicuous to their natural enemies. 



When used dry, it should be as caustic as possible. Air-slaked 

 lime is fairly effective when fresh, but fresh dry-slaked is yet better, i <?., 

 add just water enough to slake the lime into a dry powder, and sift 

 this upon soft-bodied insects like slugs of potato or asparagus beetles 

 when they are damp in the early morning. It burns holes in the 

 skin of such insects and is effective in proportion to its freshness. 



Crude carbolic acid, 1 pint to 100 pounds of lime, gives the latter 

 a light pink color and makes it a good repellant against root mag- 

 gots, &c. 



