INSECTS INJURIOUS TO HOPS 



Hop-plant borer ^ (Gortyna immanis) 

 Order — Lepidop'tera 



This is a native insect that is often seriously in- 

 jurious to hop vines in New York. It is distributed 

 from Canada to Washington, D. C, on the south 

 and westward to the Pacific Coast. 



The Hght-brown moth appears from the middle 

 of August to the last of September and deposits its 

 pinkish ribbed eggs in the leaf sheaths and on the 

 leaves and stems of grasses growing in and about 

 the hop yards; the eggs rest over the winter and 

 hatch during late April and through May; the lar- 

 vae live for a time on the grasses but later go to the 

 hops and some enter the heads where they cause 

 ''muffle" heads; others go to the stems and work 

 downward to the roots where they eat out shallow 

 grooves in the surfaces of the roots or burrow in 

 the centers of the root; in from 9 to 12 weeks they 

 mature and pupate in the soil, the moths appearing 

 in August ; there is one generation a year. 



Control — Destroy all grass in and about the 

 borders of the yards; pull out all extra vines be- 

 fore June I and remove them some distance from 

 the yard ; try paradichlorobenzene, using a few crys- 

 tals in each hill and covering with dirt. 



The hop-plant louse ^ (Phorodon Jnimuli) 

 Order — Hemiptera 



This insect is widely distributed here and in Eu- 



1, - Hawle>^ — Cornell Univ. Expt. Stat., Memoir 15. 



109 



