64 journal of economic entomology [vol. 12 



Possible Results from a Series of Annual Surveys 



The immediate object of the two surveys completed was to obtain 

 definite knowledge regarding the distribution of wheat pests, especially 

 jointworm and Hessian fly so we could furnish reUable and immediate 

 advice to our farmers as to the risks they were taking in the various 

 quarters of the state if they seeded wheat and to tell them how to 

 minimize the damage. The date for seeding, also cultural and fer- 

 tilizer practice were recommended on the basis of our findings. This 

 information was disseminated by letters to all the county agricultural 

 agents, through press bulletins, by special articles in the agricultural 

 papers and through special reports printed in the September monthly 

 bulletins of the Agricultural Experiment Station which reach about 

 50,000 farmers. 



Results with other insects, such as the Potato aphid, were given out 

 somewhat differently but knowledge gathered about them should be 

 considered an immediate result of the survey. 



But large-scale and long-term observations of this kind can possibly 

 throw some hght on such questions as these: What percentage of in- 

 festation constitutes a Hessian fly menace? Can a severe outbreak 

 of Hessian fly approach undetected in a state where such surveys are 

 made annually? Is a 3 per cent infestation a menace sometimes when 

 a 20 per cent infestation is not at other times? Do weather condi- 

 tions or parasitic "wheels within wheels" determine the increase? Is 

 the menace greatest from nearby localities with ordinary infestation or 

 from great areas of highly infested stubble at a long distance away? 

 If extensive migration occurs, does the fly-free date, fixed for a given 

 point by experimental sowings or by the law of latitude, altitude, etc., 

 remain effective for this point, with a badly infested large area fifty 

 or seventy-five miles to the south? If the data we are securing are too 

 meager to answer such questions, how much more do we need, and of 

 what sort, in order to obtain the answers desired? 



Mr. T. J. Headlee: There are two questions that I would like 

 to ask the speaker. Does the pink and green aphis of the potato and 

 tomato appear on these plants in small numbers, then gradually by 

 normal increase, create the serious infestation, and is it possible to find 

 a time before the plants assume a recumbent habit of growth when the 

 lice may be destroyed by ordinary potato and tomato spraying machin- 

 ery? Did the speaker attempt to destroy these lice by spraying? 



Mr. H. a. Gossard: I will ask Mr. Houser to answer that. 



Mr. J. S. Houser: We can detect an outbreak of the pink and 

 green potato aphid at an early stage and particularly during the earlier 



