CONTROL OF CODLING MOTH IN COLORADO. 15 
Plat VI, which was sprayed six times with arsenate of lead and 
fish-oil soap, yielded 78.06 per cent of apples free from worms, which 
was the highest percentage of uninfested fruit in the orchard. Also 
the average number of worms for all apples was as low in this plat 
as in any other. The percentage of all apples free from worms and 
stings in plat VI was 46.22, which was not as high as that obtaining in 
plats IX (46.44 per cent), V (47.84 per cent), and IV (49.82 per cent). 
Plat IX produced the next best results, 76.53 per cent of all the fruit — 
being free from worms as a result of seven applications of arsenate of 
lead; plat V, with five treatments supplemented with the codling-moth 
trap, yielded 72.29 per cent of uninfested fruit; plat IV, 72.05 per 
cent, with six applications of arsenate of lead and nicotine sulphate. 
Two other plats, I and VIII, produced 70.99 and 73.49 per cent of 
worm-free fruit, respectively; the former being sprayed six times with 
arsenate of lead, supplemented with the codling-moth trap, and the 
latter having only five applications of arsenate of lead. Plat II, 
which received six applications of arsenate of lead, yielded but 62.10 
per cent of worm-free fruit and but 27.04 per cent of fruit free from 
worms and stings. Apparently the infestation in this plat was some- 
what heavier than that which prevailed in some of the other plats. 
Plat III was treated six times with nicotine sulphate, which resulted 
in but 37.97 per cent of fruit free from worms. The percentage of this 
fruit free from stings was relatively high (88.62 per cent), a condition 
which would naturally be expected, owing to the fact that the majority 
of the larve that attacked the fruit were able to enter it without being 
killed by the spray. Attention is called to the fact that in this plat 
(plat III) 18.07 per cent of all the worms infesting the apples entered 
by way of the calyx end and that 22.39 per cent of the wormy apples 
were infested at the calyx. In plat VII arsenate of lime was used with 
unsatisfactory results, there being 36.51 per cent of worm-free apples 
and -only 20.33 per cent of the fruit free from worms and stings. 
Plat X was sprayed at the same time as the plats that had six treat- 
ments, except that the calyx application was omitted, thus making 
a total of five treatments. The percentage of worm-free fruit was 
46.33, and the percentage of all apples free from worms and stings was 
25.36. It is worthy of note that the percentage of worms entering 
the calyx was high (29.83 per cent), and that 37.42 per cent of the 
wormy apples were infested at the calyx. 
Plats XI, XII, and XIII were dusted six times with mixtures con- 
taining 20, 15, and 10 per cent of arsenate of lead, respectively. The 
results of these treatments indicate quite conclusively that dusting is 
unsatisfactory for the control of the codling moth in the Grand 
Valley. With as much as a 20 per cent lead arsenate mixture only 
40.75 per cent of the fruit was free from worms; with a 15 per cent 
lead arsenate mixture there was 34.58 per cent of worm-free fruit; 
