162 PESTS OF GARDEN AND FIELD CROPS 
The Hop Flea-beetle (Psylliodes punctulata Melsh.) 
Leaves of hops, sugar beets, and some other plants are attacked by 
very small, active beetles, which feed at first on the tender shoots and 
buds and later eat holes in the leaves. The adult is about one tenth 
of an inch long, shining black, its upper surface marked with many 
minute pits in regular rows. 
The larva is slender, whitish, and lives in the ground. There are 
two generations in the hop regions of the 
north Pacific coast. The insect hibernates 
as an adult. 
: On sugar beets control is not easy. Bor- 
\ 
deaux acts as a fairly effective repellent. A 
fair proportion of beetles may be poisoned by 
applying arsenicals. 
Fic. 173.— The Hop Flea- Where the beetles appear suddenly in de- 
beetle. Enlarged and 
natural size. Original. 
structive swarms on hops, their numbers may 
be reduced materially by brushing them from 
the vines and catching them on sticky shields made by stretching cloth 
over light frames and coating the surface with tar. Banding the 
vines and poles with tanglefoot before the adults first appear will 
largely protect the vines, since the adults seem to follow the habit of 
crawling up the vines instead of flying. 
The Alfalfa Leaf-weevil (Phytonomus posticus Fab.) 
Alfalfa throughout the Western states is seriously threatened by this 
pest, which is native to Europe and Asia and has accidentally been 
introduced into this country. 
The plants are injured both by the adult weevils and by their young 
or grubs. Depredations begin in early spring, when the beetles come 
out from their winter quarters and puncture the voung stems of alfalfa 
to make places for depositing their eggs. Shortly the grubs hatch 
and begin feeding on the tender leaves and the crown of the plant. 
Transformation to the adult stage begins in June, and later the beetles 
