PESTS OF THE HOP CROP. 129 



been found in the state of Washington, but the grub 

 has not been reported to damage the hop yards in that 

 state. 



In 1882 the insect was brought to the attention of 

 Professor Comstock, of Cornell University, who first 

 learned its complete life history, and in 1883 it was 

 investigated by Dr. J. B. Smith, then an agent of the 

 United States Department of Agriculture. Since that 

 time no reports of serious damage have been received. 

 A prominent hop grower writes me from Richfield 

 Springs, N. Y,, under date of January 20, 1898, that 

 the grub usually eats off some vines, but seldom does 

 much damage. Skunks, he writes, are plentiful, and 

 they dig the grubs out of the hop fields in the summer. 



The adult moth of the hop grub, shown at Fig. 63, 

 lays its eggs in the early part of the season upon the 

 young shoots of the plant. The young caterpillars, 

 which are slender and greenish in color, spotted with 

 black, bore into the vines just below the tip and remain 

 at this point for some time. The head turns downward 

 and stops growing. Such vines are called "muffle 

 heads" or "stag vines/' and sometimes "bullheads," 

 by the growers, and the caterpillar inhabiting them is 

 called the "tip worm." A little later the grub drops 

 to the ground and enters the stem at the surface of the 

 ground. It is then called the "collar worm." It 

 changes to a dark, whitish color with black spots. 

 About the end of July or the first of August it becomes 

 full-grown, and transforms to pupa near the roots of 

 the plant. The moths seem to issue in part in the 

 fall and in part in the spring, and the insect, therefore, 

 passes the winter in the moth state under rubbish and 

 in fence cracks, as well as in the pupal state under- 

 ground. 



As to remedies, where the insects are really abun- 

 dant, it is always desirable that the men engaged in ty- 

 ing the vines should pinch off affected tips and crush the 

 9 



