1916.] PUBLIC DOCUMENT — No. 31. 67a 



would reach, and plowing once or twice to reach the more 

 deeply placed pupse was also suggested. 



Later, when the beetles emerged, trapping methods were 

 resorted to with considerable success. Boards, burlap and weed 

 piles placed in the rows between the beds ill gave their quota 

 ol* beetles, but the weed piles proved most effective, more being 

 taken under them than under boards and burlap together. The 

 traps were most effective during hot, dry weather, few being 

 taken under them on cloudy, damp days. 



To prevent the insects from laying their eggs near unaffected 

 trees in the blocks, the ground immediately around the stems 

 was heavily sprayed with one pound of whale-oil soap in four 

 gallons of water; with kerosene emulsion; and with Black-leaf 

 40 in different parts of the nursery, in the hope that these 

 • materials would act as repellants. It was also advised that the 

 beds cleared of plants be not reset until after the adult beetles 

 had disappeared, so that there should be no inducement for 

 egg-laying there. The results of these treatments cannot be 

 determined with any certainty before the spring of 1916. 



Daring these investigations Dr. Hopkins of the Section of 

 Forest Insect Investigations of the United States Bureau of 

 Entomology, and one or two of his assistants also visited the 

 nursery, and the recommendations for treatment were gone over 

 and considered by them also, the two offices co-operating in the 

 investigation. 



All the regular lines of investigation have been continued, and 

 it is believed that with the season of 1916 some may be com- 

 pleted and attention given to other problems awaiting study. 

 Progress in them all has been as satisfactory as could be ex- 

 pected when the amount of time available for the purpose, with 

 the working force provided, is taken into consideration. At the 

 present time this working force is about equivalent to the entire 

 time of one man, who must attend to the station correspond- 

 ence; conduct all the rearing of specimens sent in as causing 

 trouble which cannot be identified in the stage in which they 

 are received; apply several thousand sprays under varying tem- 

 peratures and humidities to eight or ten different kinds of trees 

 at some distance from headquarters, and visit them three or 

 four times on succeeding days to ascertain results; give various 



