THE WESTERN CABBAGE ELEA-BEETLE. LV 
by frequent cultivation and heavy manuring in order to stimulate 
the growth of the plant and enable it to recuperate from insect attack. 
The irrigation system should be so installed that it may be kept 
constantly in working order, that the plants may not suffer at any 
time for lack of moisture. It should be unnecessary to add that the 
crops be kept free from other insects and from disease. 
IRRIGATION. 
Irrigation has been suggested as a remedy for the hop flea-beetle 
in its occurrence on sugar beets and should be of value where irriga- 
tion is practiced on other crops. Its effectiveness could be increased 
by brushing the plants, causing the beetles to jump into the water 
and be carried away or drowned. 
MECHANICAL TRAPS. 
The use of sticky shields and tarred boards, which have proved 
effective in the control of the hop flea-beetle in hop yards, might be 
used against this pest when it occurs in its greatest numbers. The 
conditions, naturally, are different, but there might be some cases 
where either would prove effective. 
In 1914 Prof. H. M. Lefroy (9) made use of what he calls the Wisley 
turnip-fly trap against two allied species of flea-beetles 10 in their 
occurrence on turnip with what he describes as amazing results, due 
apparently solely to the growth the seedlings make when their leaf 
surface is entirely unharmed. This trap is made of two boards set 
at a slope on a pair of runners like those of a sledge with a space 
between. The trap is drawn along the rows so that the plants pass 
through the space in the middle. In order to disturb the beetles a . 
loop hangs from a crossbar and brushes the plants. The boards are 
smeared with a sticky substance, which captures the beetles as they 
fly up. The illustrations furnished of the trap show that it can be 
easily made and should prove quite successful where radish, turnip, 
and similar crops are planted in rows, but, of course, would not be of 
service where the seed is sown broadcast. 
TRAP CROPS. 
The fondness of this, as well as other cabbage flea-beetles, for 
radish, mustard, and turnip suggests the employment of these as 
early trap crops to attract the beetles from the later-appearing main 
crops of cabbage, sugar beet, and others. The beetles may be swept 
up from these trap crops by means of a bag sweep net of the type 
used by entomologists to collect beetles and similar insects. This 
should afford protection for the main crop. 
10 Phyllotreta comobrina Curt., and Ph. undulata Kutsch. 
