BUREAU OF ENTOMOLOGY. 529 



complete survey of injurious insects of the cranberry bogs in "Wis- 

 consin has been about completed, and a good knowledge of the life 

 history of most of these has been obtained. These studies have been 

 made on the bogs under perfectly natural conditions and will be of 

 the utmost value as a basis for making recommendations for their 

 control. Spraying operations under way in 1909 were carried through 

 the season and the results recorded in a way to show the benefits in 

 dollars and cents. The general absence of the fruit-worm, which had 

 been very destructive the year previous, however, resulted in less 

 marked benefits than previously obtained; nevertheless, the results 

 from spraying showed a considerable improvement over unsprayed 

 plats. This work will be concluded at the close of the present season, 

 and it is planned to extend it to cranberry bogs in other States. 



CEREAL AND FORAGE-PLANT INSECT INVESTIGATIONS. 



Several new problems have engaged the attention of the cereal and 

 forage insect section of the Bureau, under the charge of Mr. F. M. 

 Webster, and the older investigations have been continued. 



THE SO-CALLED " GREEN BUG." 



The spring grain-aphis, or so-called " green bug," has continued to 

 claim attention. During the autumn of 1909 it seemed to have 

 reached its usual abundance along the line extending from North 

 Carolina to New jSIexico, but the ensuing winter was normally cold 

 and restrained the pest, while in March there was an extraordinarily 

 high temperature which enabled the parasites to develop in the 

 spring, so that the pest was soon overcome by its natural enemies. 

 The reverse of this — that is to say, a warm winter and a cold spring — 

 would have certainly produced an enormous abundance of the insect. 

 This emphasizes more than ever the imperative necessity for contin- 

 uing government surveillance over the region where this pest first 

 begins its depredations in the spring. This area covers approxi- 

 mately 13 States and Territories, while the territory now known to 

 be occupied by the species, and therefore more or" less threatened, 

 covers approximately the whole United States west of about the lati- 

 tude of the city of Washington, excepting perhaps in extreme western 

 New York and Pennsylvania. At present it seems possible to diag- 

 nose the situation by keeping close watch upon the species throughout 

 the area where it first begins its ravages, and by utilizing the records 

 of the Weather Bureau. The studies of the past year emphasize the 

 statement previously made that an outbreak of this pest depends upon 

 temperature conditions beginning in the South, and the extent of its 

 ravages depends wholly upon weather conditions during winter and 

 spring. It seems, therefore, extremely desirable tliat there should 

 always be a sum available for this particular investigation. 



A complete report on this insect and its parasites will be prepared 

 for publication during the fiscal year 1911. 



WOBK ON THE JOINTWOEM. 



The investigation of the jointworm has been continued more par- 

 ticularly throughout Ohio, Indiana, and southern Illinois, but the in- 

 sect has been found injurious for the first time in the wheat in Mis- 



73477°_AGR 1910 34 



