82 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 12 



molesta in several of the states on the Eastern Seaboard. Judging by 

 our first information in regard to the pest, these fears were well founded. 

 The fruit-feeding habit seemed most serious and the progress of the 

 infestation has been carefully watched and further dissemination 

 guarded against in some instances. 



After three years' observation and investigation certain facts have 

 come to light that lead to the belief that the pest may finally come to 

 have approximately the same destructive status for peach as the cod- 

 ling-moth has at present for the apple in Avell-cared-for eastern or- 

 chards. At most, its destructive force should be no greater. 



This estimate is based principally upon the counts made at College 

 Park by Dr. Garman of the infested fruits and in part on the compara- 

 tive growth of infested and non-infested trees. 



In the face of a long standing infestation which would be rated as of 

 considerable severity, the fruit from the following varieties showed the 

 percentages of infestation to be quite small. Except in three cases, 

 the per cent of infested fruits did not amount to over 5 per cent. 

 Champion with 12 per cent infested fruit, Lyon with 13 per cent and 

 another late variety with 35 per cent were the exceptions. The aver- 

 age infestation on Greensboro, Carmen, Champion, Elberta, Late 

 Crawford, Mountain Eose, Lyon and the lihknown variety was 4.3 

 per cent based on actual counts of over 4,000 peaches. 



It may be possible to reduce this fruit infestation even more. Spray- 

 ing experiments show that the dry particles of self-boiled lime sulfur 

 will kill newly hatched larvae that attempt to crawl through them. 

 Dusting, therefore, may give greater control than spraying. 



The comparative growth of infested and non-infested twigs on bear- 

 ing trees shows only a slight advantage to the infested tree. Careful 

 measurements show that the average growth of infested twigs for 

 the season was 11.1 and for the non-infested twigs 8.8 inches. The 

 difference in this case of only 2.3 inches is hardly worthy of serious 

 consideration. 



Another factor that may have a very considerable influence on the 

 potential destructiveness of the insect is that of parasitism. Eight 

 parasites, one of the egg and the balance of larva and pupa, during the 

 past season contributed to the control of the pest. Approximately 

 60 per cent of the eggs were parasitized by Trichogramma minuta Riley. 

 About 50 per cent of the larvae and pupae were also parasitized. This 

 leaves a possible one fifth of the normal brood as survivors. The egg 

 parasitism in 1917 was 80 per cent; so that it seems fair to assume that 

 a high percentage of parasitism may reasonably be expected, particu- 

 larly since Trichogramma is a general feeder. Five of the parasites 

 were Hymenoptera and three Diptera. 



