44 N. ll. AGR. EXPERIMENT STATION. [Bulletin 151 



There is nothing to indicate, so far, that the adult flies normally travel any 

 great distance. All data on hand tend to indicate that the flies are rather 

 sluggish and are apt to remain near the place where they emerged. 



It has been proposed at various times to eliminate the Railroad Worm from 

 a given block of trees by plowing the pupae under in the spring, the idea being 

 to bury them so deep that the flies could not make their way to the surface 

 of the ground. 



Some experiments performed at the Rhode Island station indicated that 

 this plan was not feasible. Further experiments the past season at this station 

 corroborate the results in Rhode Island, and warrant the statement that it 

 is out of the question to bury the pupae so deep by plowing that the flies will 

 be unable to reach the surface. 



Certain experiments in spraying were undertaken tins season. The principle 

 involved was that of poisoning the adult fly by the use of a mixture of arsenic, 

 molasses and water distributed over the leaves of the tree by means of a com- 

 mon spray pump. This plan has been followed successfully in the case of 

 similar insects occurring in other countries. 



Through the cooperation of growers this plan of spraying was tried at several 

 different points. In most the results were negative. It seems probable 

 that in these instances the possible value of the treatment was obscured by 

 the proximity of other infested trees not so treated. Also owing to the pressure 

 of other work the grower was unable to apply the spray as often as would be 

 needed in order to keep the poisoned sweet ready for the flies throughout their 

 egg-laying season. In one instance, however, the treated tree stood alone, 

 and this tree was given repeated sprayings as primarily planned. The variety 

 was August Sweet and the fruit had been worthless for years. This tree 

 yielded this season practically perfect fruit. 



There is sufficient reason, therefore, for making further tests of this treat- 

 ment next season. To this end certain trees or blocks of trees have been 

 selected, and the proper conditions provided to insure definite tests next 

 season. 



Certain details in the habits and life history of this insect are imperfectly 

 known. These matters have been under study the past year, but another 

 season's work will be needed. 



There is a question, also, as to the possible existence of more than one 

 species of this fly in the orchards of New Hampshire. 



By way of summary, the past year's work has added materially to our knowl- 

 edge of this insect, and it is believed that another season will bring to a close 

 the major part of this investigation. 



The Influence of Temperature on Insect Transformations and 



Hibernations. 



For several years this department conducted an exhaustive investigation 

 of the influence of temperature on insect transformations and hibernations. 

 In all, many thousands or hundreds of thousands of insects were handled. 

 An immense amount of data was secured which shed much interesting light 

 on the laws and conditions governing'and attending certain phases of insect 

 growth and activity. 



