214 ANNUAL EEPOETS OF DEPARTMENT OF AGEICULTUEE. 



DECIDUOUS-FRUIT INSECT INVESTIGATIONS. 



Investigations of deciduous-fruit insects have been carried on under 

 the direction of Dr. A. L. Quaintance, as formerly. 



Apple insects. — ^The comparative studies of the codling moth 

 plamied to cover the principal apple-growing regions in the United 

 States have been continued. The investigations in Maine were 

 concluded at the close of the season of 1914 and a report upon the 

 work prepared for publication. It was foimd that in Maine the 

 codling moth develops practically but one brood of larvas each year, 

 and a single thorough spraying of trees after the falling of the blossoms 

 furnished adequate protection to the fruit. The investigations in 

 New Mexico were continued and further data obtained on the 

 control of this insect in a region where there are three full broods 

 and a partial fourth brood of larvae each year. The life-history 

 studies of the codling moth in this region have been completed and a 

 report prepared for publication. 



In the spring of 1915 a field station was established at Grand 

 Junction, Colo., in a region in which the codling moth has for many 

 years been especially troublesome. In cooperation with the Colorado 

 Agricultural Experiment Station, a thorough investigation of the life 

 history and habits of the insect will be made and extensive experi- 

 ments with sprays in orchards wiU be carried out to determine the 

 best time to make applications in order to secure control. 



During the last two or three years there has been a renewal of 

 interest in the dusting method of applying poisons and fungicides 

 for the control of apple insects and diseases. In order to obtain 

 definite information of the effectiveness and cost of the new dust 

 sprays in insect control as compared with liquid sprays, extensive 

 experiments were undertaken in the spring of 1915 in connection 

 with other work at the field stations in Michigan, Colorado, and 

 New Mexico. 



The life-history studies of the green apple aphis under way last year 

 have been completed and a report upon the work is now in preparation. 

 By the close of the season of 1915 fairly complete data will have been 

 obtained on the biology of the rosy apple aphis, which has been under 

 investigation durmg the past two years. The alternate food plant 

 has been found to be a species of plantain commonly growing in and 

 about orchards, and the destruction of this food plant should mate- 

 rially reduce the pest. Additional tests have been made in orchards 

 in the control of the woolly apple aphis by the use of poisonous sub- 

 stances in water applied to the roots of infested trees. The results 

 obtained indicate a practical remedy for this very destructive insect. 



Investigations under way, in cooperation with the Bureau of Plant 

 Industry, as to the relation of insects to the affection of apples 

 known as stigmonose, are progressing satisfactorily and have been 

 enlarged. Certain suspected species of insects have been isolated 

 and are being reared in cages on fruit trees in a way to determine 

 their possible connection with the malady. 



Peach insects. — Work with the peach borer has been continued, 

 and attention has been especially directed to determining the egg- 

 laying habits of the moth and habits of the newly-hatched larvfe in 

 entering the trees. Considerable experimentation was done m the 



