BUEEAU OF ENTOMOLOGY. 221 



The result of tlie investigation was that much additional information 

 was accumulated relative to this old and sujjposedly well-known pest. 

 Early in the spring of 1915 this species a^ain occurred in Oklahoma, 

 and at the end of the year was excessively abundant in eastern Ne- 

 braska, western Iowa, southeastern South Dakota, northeastern New 

 Mexico, and southern Virginia. 



So-called "green bug." — As reported last year, the spring grain- 

 aphis, or ''green bug," received a very serious setback in northern 

 Texas from the millions of parasites that developed on species of plant- 

 lice related to it, and it did not occur in any abundance over the area 

 where this peculiar situation regarding parasitism was observed to 

 occur. In 1915, outside of this area, which included northern Texas 

 and southern Oklahoma, the "green bug" did occur locally in de- 

 structive abundance. Such outbreaks took place in Louisiana and 

 South Carolina in grain fields. Much later in the season there was a 

 totally unexpected and serious attack on the grounds of the depart- 

 ment in Washington. Considerable areas of the bluegrass took on 

 the peculiar reddish tinge so indicative of "green-bug" attack. 



Hessian fly. — One of the severest outbreaks in the history of the 

 Hessian fly occurred during the spring of 1915 and covered most of 

 the wheat-growing States. Starting in northern Oklahoma and 

 Kansas, the infestation swept over the wheat belt northward and 

 eastward, doing most of its damage, however, west of the Mississippi 

 and north of the Ohio and Potomac Rivers. For a number of years 

 all of the field stations located within the range of this pest east of the 

 Rocky Mountains had observed the continued increase in numbers 

 and had made unusual exertions to determine the cause of this increase. 

 Nearly all attempts to rear parasites were without avail. The prin- 

 cipal parasite was conspicuously absent from all rearings and the out- 

 break that followed was predicted. Several publica,tions were issued 

 during the year warning the farmers of an impending outbreak and 

 giving them advice relative to the management of their fields in such 

 a way as to reduce the damage. In the fall of 1914 it became quite 

 evident that there would be much damage to the crop in the spring of 

 1915, and a number of men were engaged in watching carefully the 

 results of preventive measures that had been applied, as well as the 

 extent to which volunteer wheat entered into the problem of control. 

 Early in June it became evident that unless something was done_ there 

 would be a recurrence and perhaps even a more serious outbreak in the 

 fall of 1915. To meet the overwhelming number of requests for infor- 

 mation, Circular No. 51 was issued from the Secretary's Office. The 

 first edition of 40,000 copies was soon exhausted and a second edition 

 of 150,000 copies was printed. These have been distributed through 

 the agency of county demonstrators and volunteer crop reporters from 

 the different field stations located within the area covered by the 

 threatened invasion. 



WiREWORMS. — A buUetiii was issued giving the more practical 

 results obtained in the investigation of wireworms. Many experi- 

 ments in soil fumigation were performed, but results require further 

 verification before their practical value can be accurately determined. 

 Cultural experiments were conducted in various States under different 

 soil conditions. Some of these insects are of very slow development 



