HABITS. 13 
carefully removed from each leaf. When mature the two females 
that survived upon the isolated leaves were carefully watched to 
be sure that no male mite reached them. Thirty-three eggs were 
deposited by these virgin mites and all of the 26 that hatched were 
males. % 
HABITS. 
HABITATION. 
Small numbers of mites were observed during the early summer on 
the underside of hop leaves. A few strands of web were usually pres- 
ent to begin with, and as the number of mites increased the web 
became more extensive and was observed frequently to cover, in an 
irregular manner, the entire underside of the infested foliage. The 
lower leaves were first attacked, but as infestation increased these 
leaves, which were severely injured, began to dry and thus forced an 
upward migration of the mites. By August the entire vines were 
infested and in severe cases mites were observed upon the surface 
as well as the underside of the leaves. 
PROTECTION. 
Inhabiting as they do the underside of the leaves, the mites are 
well protected from wind and other climatic conditions. Further 
than this, the web which is spun indiscriminately across the under- 
side of the infested foliage affords the mites much protection. Where 
the finer mist sprays were used the webs were frequently not pene- 
trated and the mites beneath remained uninjured. This combina- 
tion of web and leaf affords the mites great freedom from injury. The 
web of the red spider is spun by either sex, and is at all times carried 
about by the mite as a guard against falling. It thus becomes scat- 
tered over the underside of infested leaves and other objects over 
which the mites may crawl. 
HIBERNATION. 
A careful examination, during February and March, 1911, of soil 
and hop roots taken from fields which were badly injured by the red 
spider in 1910 failed to reveal any hibernating mites or overwintering 
eggs. During 1911 the mites were found only upon violets and mal- 
low ( Malva parviflora) which grew in a flower garden half a mile from 
the hopyards, but they were observed in considerable numbers the 
following fall, winter, and spring upon wild morning-glory and mallow 
in all parts of the hopyards. 
It is evident, therefore, that the mites pass the winter upon wild 
plants in and around the hopyards, as has been found true of the red 
spider attacking cotton in the Southern States, by Mr. E. A. McGregor 
of this bureau. 
