﻿12 



BULOJETIN las'?, U. S. DEPAETMENT OF AGRIGULTXTRB 



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 t^ 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 



Fig. 5. — The strawberry rootwonn : Characteristic 

 feeding of the adults on terminal growth and 

 flower bud 



. The leaves (fig. 1) fur- 

 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 duds " of rose plants ty strawberry rootworm 

 'beetles in three different establishments 



Establishment 



Total number of— 



Per- 

 centage 

 of in- 

 jured 

 buds 



Plants 

 examined 



Breaking 

 buds 



Injured 

 buds 



A. . 



50 

 30 

 53 



2,313 



1,013 



590 



878 

 637 

 349 



38 



B - 



62 



C 



59 







