75 



616. HOP PLANT-LOUSE. 

 Phorodon hamuli. 



Bemedtes and preventives: The attacks of the Hop Plant- 

 louse may be prevented very satisfactorily by first destroying all the 

 wild plum trees in the neighborhood except a few which may be left 

 for trap plants. These latter should be sprayed with strong kerosene 

 emulsion in September to destroy the return migrant and its progeny, 

 and also the winter eggs, and again in spring to reach the two or three 

 plum generations which may have developed from eggs escaping the 

 fall treatment. Secondly, by destroying the hop plants as soon as the 

 crop is gathered. Thirdly, and perhaps least effectively on account of 

 the difficulties attending the treatment, spraying the hop plants with 

 kerosene emulsion diluted about ten times. Fourthly, spraying the 

 affected hop plants with a dilute decoction of quassia chips. 



617. HOP PLANT-LOUSE. 



Phorodon hiunuli. 



Belied y : Kerosene emulsion. 



Kerosene gallons.. 2 G7 per cent. 



Common or whale oil soap pound . . £ 



Water gallon.. 1 33 per cent. 



Heat the solution of soap and add it boiling hot to the kerosene. 

 Churn the mixture by means of a force pump and spray nozzle for five 

 or ten minutes. The emulsion, if perfect, forms a cream which thick- 

 ens upon cooling and should adhere without oiliness to the surface of 

 glass. Used for spraying plum trees in spring and fall, also applied 

 to affected hop plants by means of a force pump and spray nozzle. 



618. HOP PLANT-LOUSE. 



Phorodon humnli. 



Ke:\iedy: Quassia. A decoction of quassia chips, made by steeping 

 them in water, is recommended as a wash for the Hop Louse and gives 

 fairly good satisfaction, but is less serviceable than the kerosene emul- 

 sion. 



619. CHINCH BUG. 



Blissus leucopterus. 

 The Eggs. 



The greatly enlarged papier mache model represents the form of the 

 egg and the terminal cap. The eggs are three-tenths of an inch long, 

 the top being squarely docked and surmounted by four round tubercles 

 near the center. Color from pale whitish to amber. (See No* 272.) 



620. CHINCH BUG. 

 Blissus leucopterus. 



First larval stage. 



This stage, represented greatly enlar-ed in the model, differs from 

 the adult in being more elongate and in having two-jointed taisi, the 



