ILLUSTRATIONS. 
Page. 
Plate I. Fig. 1. — Fallen hopvine, showing characteristic silvery web and 
clusters of red spiders {Tetranychus bimaculatus). Fig. 2. — Fallen 
hopvines, showing silvery web, on which red spiders are clustered . . 16 
II. Fig. 1. — Male hopvine injured by the red spider. Fig. 2. — Male hop- 
vine uninjured by the red spider 16 
III. Fig. 1. — Spraying hopvines with power outfit for the red spider. 
Fig. 2. — Applying precipitated sulphur in dust form as a remedy 
against the red spider 20 
IV. Fig. 1. — Sweet peas infested by the red spider, but protected by 
dusting, at intervals of one week, with precipitated sulphur. 
Fig. 2. — Sweet peas, growth aborted, blossoms indifferent, and vines 
nearly killed by the red spider 20 
V. Fig. 1. — Comparison of healthy hops with those infested by the red 
spider. Fig. 2. — Leaf of hop, the left half of which was sprayed 
with lime-sulphur and flour paste and the right half with lime- 
sulphur alone 24 
VI. Fig. 1. — Cooking flour paste out of doors. Fig. 2. — Large power 
spraying outfit, showing lines of hose running into hopyard 28 
TEXT FIGURES. 
Fig. 1. The red spider ( Tetranychus bimaculatus) : Egg 10 
2. The red spider: Larva 11 
3. The red spider: Adult female 12 
4. The red spider: Adult male 12 
5. Track of a red spider on blotter 14 
6. Hopvines banded with tanglefoot in an attempt to prevent the mites 
from ascending 28 
7. Hopvine tied high and not stripped; lower leaves difficult to spray.'. . . 31 
8. Hopvine tied high and stripped; lower leaves matted and difficult to 
spray 32 
9. Hopvine tied low and stripped; leaves readily sprayed 33 
74955°— Bull. 117—13 2 7 
