18 THE RED SPIDEE OX HOPS IN CALIFORNIA. 
Even when they can be picked the quality is often severely injured. 
Dr. W. W. Stockberger, of the Bureau of Plant Industry, reports 
upon some samples of "spider hops" as follows: 
Of these No. 1 is, I should say, practically unsalable. Not only is the color very 
poor, but it is not uniform and shows very evidently the red discoloration produced 
by the activities of the "spider."' The aroma is also far from pleasing. The second 
sample, which showed some damage by the spider, is far from being a first-class hop; it 
of course is still marketable. 
Thus, even though a large crop is harvested its value may be 
greatly reduced by the injury due to the attack of the red spider. 
EFFECT UPON MAX. 
Some of the workmen of the hop ranches stated that during hop 
picking they had been troubled by the mites getting upon their 
bodies and causing an irritation. This point was investigated; 
several hundred mites were liberated upon the hands and arms of 
the writer and allowed to crawl around for 20 minutes. A barely 
detectable itching was the only sensation observed. The irritation 
mentioned by the men was probably due to scratches of the hop- 
vines and not to any irritation caused by mites. 
DISTRIBUTION IN THE FIELD. 
It was the opinion of some hop growers that the red spider appeared 
first along the roads and fences and gradually worked into the fields, 
but observations in several localities did not bear out this point. 
The mites first appeared within the hopyards and not especially 
along the borders, and although the increase was rapid, the infestation 
was evenly distributed. 
The dust from the roads collecting on the foliage made the web 
show very distinctly and the growers, judging the extent of an 
infestation by the amount of web that can be seen, would naturally 
think that the infestation started where the web was most noticeable. 
This accounts for the erroneous opinion mentioned above. 
Mr. W. H. Volck, who made some observations upon the red spider 
at Wheatland, Cal., in 1902, suggested that since the infestation was 
so sudden the mites might possibly have traveled through the air 
on webs, like the ''balloon" spiders. To test this point four dozen 
sheets of tanglefoot fly paper were tacked to the trellis poles in 
various parts of the infested yards at Perkins. Cal. They were put 
out in June. 1911, and when collected in September many insects 
were found embedded in the hardened tanglefoot, but no mites were 
observed. During the migrations in August mites dropping from 
