54 



DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



HABITS OF THE ADULT. 



About the middle of June, just before the blossom-buds of the 

 grape break into full bloom (fig. 16), the adult rose-chafers com- 

 mence to appear upon the vines. They at once proceed to attack the 

 blossom clusters and injure the unexpanded blossom-buds by cutting 



a hole through the side of the 

 bud and eating out or injuring 

 the small ovary. (See fig. IT.) 

 Since the blossom-buds are quite 

 small, a single beetle will destroy 

 a large number of blossoms, and 

 if the beetles are at all numerous 

 almost the entire crop may be 

 destroyed. Sometimes in badly 

 infested vineyards the blossom 

 clusters will be swarming with 

 a squirming mass of beetles (fig. 



Fig. 16. — Condition of the grape blossom- 

 buds at the time the rose-chafer {Mac- 

 rodactylus subspinosas) first appears, 

 and when the first poison spray should 

 be applied. Enlarged. (Original.) 



18, /) and the whole cluster will 

 be quickly reduced to a frayed 

 and blackened mass of broken 

 and injured blossom-buds. Our 

 observations lead us to believe 

 that by far the greater percent- 

 age of injury to the grape crop is done previous to the opening of the 

 blossom-buds and to a less extent while the grapes are actually in 

 bloom and for a few days succeeding the blooming period. (See fig. 

 19.) Later, when the injured blossom-buds and berries have dropped, 



Fig. 17. — Work of the rose-chafer : a, In- 

 jury to grape blossom-buds Joy feeding 

 of rose-chafer ; b, injury to the ovary 

 resulting in the destruction of the berry. 

 Greatly enlarged. (Original.) 



