PREFATOEY NOTE. 



The following article by Mr. Johnson, one of the entomological 

 assistants of the State Laboratory of Natural History, detailed for 

 service in the office of the State Entomologist, contains in part 

 results of work done by him as a graduate student of Stanford 

 University before his connection with this institution, and written 

 up as a thesis for the master's degree. Much of his time has been 

 given to the subject, however, since his engagement here, and a 

 large part of the present paper is based upon results of this 

 later work. 



Although the Mediterranean flour moth has not yet been found 

 to infest any mills in this State, its distribatiou in our vicinity 

 makes it practically certain that it will eventually appear within 

 our limits, and a comprehensive article on it is consequently even 

 more timely than it would be if withheld until after the threatened 

 invasion were an accomplished fact. 



It is of great consequence to every miller that he should be not 

 only forewarned of his liability to serious annoyance and heavy 

 loss by the work of this worst of the pests of the flouring mill, 

 but that he should also be thoroughly forearmed with informa- 

 tion as to the signs of its presence, the characteristics by which it 

 may be unmistakably recognized, and the measures of prevention 

 and destruction to be used against it. 



I have gladly availed myself, therefore, of this opportunity to 



put the millers of this State and of the country in possession of 



the esseiltial facts, and to have compiled for the benefit of the 



working entomologist a complete review of the history and results 



of previous studies of this insect pest. 



S. A. Forbes. 



