8 



FARMERS BULLETIN 843. 



the unsprayed plat (Plat IV) the injury by the first brood of larvae 

 amounted to 29.90 per cent, while the second-brood infestation was 

 only 10.61 per cent, thus showing the proportional attacks on the nut 

 crop by the first and second broods of larvae. 



The results of the spraying experiments for the season of 1916 are 

 shown in Tables 2 and 3. The two series of experiments, as outlined 

 in these tables, were conducted in the same orchard, but a distance 

 of fully one-fourth of a mile separated them. 



TABLE 2. Spraying experiments against the pecan nut case-bearer, Monticello, Fla., 1916. 



As will be noted in Table 2, the best results were obtained on Plat 

 I, which received three applications, there being 95.16 per cent of 

 sound nuts. The infestation in the unsprayed plat (IV), however, 

 was not severe, since 82.66 per cent of the nut crop came through 

 in sound condition. The actual percentage of infestation in this plat 

 was 17.33 of the total crop, 12.14 being due to the first-brood larvae. 

 Plats II and III showed 93.44 and 92.62 per cent of sound nuts, re- 

 spectively. The benefit to each sprayed plat over the check (Plat 

 IV) is given in percentages as foUows: Plat I, 12.49; Plat II, 10.77; 

 and Plat III, 9.95. 



TABLE 3. Spraying experiments against the pecan nut case-bearer, Monticfllo, Fla., 1916. 



As will bo noted in Table 3, Plat V, which received one application 

 on May 12, gave only 77.81 per cent of sound nuts, as compared with 

 75.78 per cent of sound nuts on the unsprayed plat (VI), showing 

 a benefit of only 2.03 per cent from the treatment. Plat VII, which 

 received one application on May 24, showed 83.75 per cent of sound 

 nuts, while Plat VIII showed a percentage of 89.85 of sound nuts. The 

 benefit to each sprayed plat over the check (Plat VI) is shown in the fol- 

 lowing percentages: Plat V, 2.03; Plat VII, 7.97; and Plat VIII, 14.07. 



In working out control measures for this pest, it has been deter- 

 mined that the spray applications must be made during very limited 

 periods in order that satisfactory results may be obtained. In spray- 

 ing for this species timeliness and thoroughness of application are, 



