r 



BLUEBERRY INSECTS IN MAINE. 263 



(Bul. 171, N. H. Exp. Sta.). Since the blueberry and huckle- 

 berry flies are so much below what must be considered the 

 normal size of this species, and since apparently they are decid- 

 edly restricted in their breeding habits, it does not seem proba- 

 ble to the writer that any species of either Vaccinium or Gay- 

 lussacia was the original host of the insect in question. This 

 would seem to leave the haw as the only remaining possibility. 

 Professor O'Kane has suggested four species (1. c. pp. 16-17) 

 whose range and fruiting habits would be suitable in this con- 

 nection. These are Crataegus coccinea, C. punctata, C. macra- 

 cantha and C. mollis. Since Rhagoletis pomonella Walsh has 

 now been bred quite extensively from haws and since adults so 

 bred are about normal in size, the writer would suggest that 

 some one of the four species of Crataegus listed above was the 

 original host, and that the species has spread on the one hand 

 to the apple and related fruits, and on the other to the huckle- 

 berry and blueberry, in which an independent and quite dififerent 

 strain has arisen. 



It is tempting to try to include the chokeberry in the above 

 scheme since it belongs to the genus Pyrus, especially after it 

 has been demonstrated that successful larval transfers may be 

 made to this fruit ; but if the chokeberry were really an accepta- 

 ble home to Rhagoletis pomonella, occurring abundantly as it 

 does on the plains, it would certainly be heavily infested. 



NATURAL ene;mie;s. 



A hymenopterous parasite, Biosteres rhagoletis Richmond, 

 (Braconidae) was bred in considerable numbers from puparia 

 obtained from blueberries in 1913. Under laboratory conditions 

 the adults emerged at various times between February 25, 1914, 

 and April 21, 1914, from the pupae of Rhagoletis pomonella. 

 Specimens of this species were swept on the blueberry barrens of 

 Washington County during the summer of 1914. Apparently 

 they had considerably reduced the number of maggots as com- 

 pared with the preceding season, and certainly must render very 

 efficient aid in holding the maggot in check. 



Adults were observed quite commonly on the barrens hover- 

 ing about the blueberry bushes on August 26, 191 5. They were 

 rather slow moving and not very shy. In one case the writer 



