se hs 
12 BULLETIN 1357, U. S. DEPARTMENT OF AGRICULTURE — 
HABITAT 
On bright days the beetles hide in the dried leaves on the bushes, 
between adjacent green leaves, in the crotches, or in any place where 
they are away from the light, and come out to feed in the late after- 
noon (Fig. 4). Usually wherever fresh feeding is evident on the 
foliage an examination of the nearest dry leaf will reveal their | 
presence. They may often | 
be found in depressions 
one-half inch deep in the 
ends of cut stems where 
the pith has dried out. 
Syringing causes many 
of the beetles on the plants 
to drop to the ground, 
where they may remain 
for some time. Watering. 
as well as syringing wets 
the soil to such an extent 
that the adults dislike it 
and run up the stems, 
stakes, and plants, or rest 
on the wires, apparently to 
dry themselves. While the 
beetles were thus exposed, 
more than a thousand were 
collected within an hour 
by the workmen in a house 
containing 30,000 plants. 
Two or three hours after 
syringing the beetles again 
hide among the foliage of 
the plants or elsewhere. 
FEEDING HABITS 
Fic. 5.—The strawberry rootworm: Characteristic 
feeding of the adults on terminal growth and The leaves (fig f fur- 
flower bud 5 
nish most of the adults’ 
food, although the bark of the stems, the buds (fig. 5), and the flow- 
ers do not escape attack. The beetles are attracted particularly by 
the sap on the ends of new-cut stems, and in the evening as many 
as 10 have been found feeding there. Under these conditions hand 
picking may be successfully practiced. In the absence of foliage the 
beetles cause very serious injury by feeding on the breaking buds. 
The extent of this feeding is shown in Table 3, which records data | 
gathered in three separate greenhouses. | 
TABLE 3.—Injury to “wood buds” of rose plants by strawberry rootworm 
beetles in three different establishments 
Total number of— | Per- 
Establishment ——— of in- 
Plants | Breaking} Injured jured 
jexamined) buds | buds | buds 
=| 
Ni. 2 SUSAR eratista Manatees hte NE 8S | 50 2,313 878 38 
Bre Wee INS Se SEN eas | 30 1,013 637 62 
CRS gow ery ee eee embpaetag, Mg loc oa | 53 | 590 | 349 
