August, '21] STEARNS: ORIENTAL PEACH MOTH 337 



the fruit spurs, while the growth was still tender enough for feeding, 

 and undersized, and in some instances, deformed fruits resulted. It 

 was found, moreover, that fully 41 per cent of the first brood injured 

 twigs grew no more during the season. 



In 1920, the injury to late peach fruit was much greater than in pre- 

 ceding years. About mid-September, an examination made in an old 

 infestation of considerable severity, by actual count of between 3000 

 and 4000 fruits on trees of the varieties Smock, Heath and Salway, 

 showed infestations of 12, 43 and 58 per cent for these respective va- 

 rieties. 



These facts, and )thers of lesser importance, emphasize the neces- 

 sity for, and warrant the publication of, increased knowledge concern- 

 ing the control of the insect either by natural or artificial means. 



Parasitism 



In lack of an effective method of orchard control for the oriental 

 peach moth, those who have published notes have commented hope- 

 fully on the fact, that this recently imported insect had become sub- 

 ject immediateh^ to the attack of numerous parasites of our native 

 species. Altogether, no less than nineteen hymenopterous and dip- 

 terous forms are known now to parasitize the peach moth in its egg, 

 larva and pupa stages. The writer, in 1918, succeeded in rearing elev- 

 en species of parasites, the records of which have been published al- 

 ready.' Seven of these species had not been known to attack this in- 

 sect. During 1919 and 1920, while continuing the study of the peach 

 moth in northern Virginia, further attention was given to parasitism. 

 The list of parasites reared each year has been much the same, the 

 only new record being that of a single species of Apanteles^ taken in 

 1920. However, in connection with from 1500 to 2000 orchard col- 

 lected larvae, a number of interesting observations have been made. 



Perhaps the most important fact is that parasitism is keeping pace 

 with the increasing numbers of the host. It 1918, parasitism, while 

 attaining and continuing at an average of 35 per cent for small numbers 

 of larvae and pupae during the latter part of the summer, did not ex- 

 ceed 6 per cent in earlier collections. For all three summer broods in 

 1920, an average of 20 per cent parasitism was recorded, and the aver- 

 ages, 17, 16 and 25, for the first, second and third broods, respectively, 

 show little variation. It has been encouragmg, also, to find a uni- 



ijour. Eco. Ent., Vol. 12, No. 4, August, 1919, pp. 347-348. 

 ^Kindly determined by Mr. S. A. Rohwer, U. S. National Museum. 



