CONTROL OF CODLING MOTH IN COLORADO. 8 
TABLE 1.—Comparison of mean normal temperature and precipitation, Grand Junction, 
Colo., and Rochester, N. Y. 
Gr Bnd onerous Rochester, N. Y. 
Month. Mean Mean Mean Mean 
normal | normal | normal | normal 
temper- | precipi- | temper- | precipi- 
ature. tation. ature. tation. 
Serie Inches. 8 Inches. 
MSL pens ay iets ae Bale ects alee jet aitinrsieieia aid, atcislecnyeials chdimsia,a sie 58.9 0. 92 56. 7 2.94 
STU Gee ese oe Fe ee oe Sth set ti ce coy iia ine SER Sire laline 72.6 0. 40 65. 9 3. 13 
SILLY ent ee Nee cto ak aie ins Deine ie metas Sai cisine as ele wie sicle 79. 2 0. 50 70.4 3. 09 
PANTO UIS tetas eam ese a octets te Sale ek scree oan eta aii eg 76.1 1. 04 68. 3 2.96 
NOPLOMDOEA -ctece Sacco e 5 sun ce a cere ae care SPER EE eee Ss 66. 4 0.95 61.9 2.32 
IASVerace OTsbotalape ws ae as Sek ce sis sed see tere eee 2 70. 6 3. 81 64. 4 14. 44 
In the course of the life-history investigations in the Grand Valley 
it was found that a female moth deposited as many as 316 eggs and 
that several laid over 300 eggs each.’ In other localities where the 
Bureau of Entomology has conducted similar investigations, the 
fecundity of the female moth has never been found to be so high. 
The nearest approach to the individual egg production in the Grand 
Valley was found in the Pecos Valley of New Mexico, where like 
climatic conditions obtain and where one female moth was recorded 
to have produced 259 eggs.® In the fruit belt of western Michigan, 
where the weather conditions approximate those of western New 
York, the most eggs laid by a moth, according to the records of 
A. G. Hammar, was 161.’ 
It has been quite generally established that semiarid climatic 
conditions are very favorable to the development of the codling moth, 
whereas humid conditions and lower temperatures retard its develop- 
ment. 
SPRAYING EXPERIMENTS IN THE GRAND VALLEY. 
Spraying experiments were conducted in several orchards during 
the seasons of 1915, 1916, 1917, and 1918, on representative apple 
varieties. The results herewith presented, however, are confined to the 
Ben Davis and Gano, since the Grand Valley fruit growers generally 
experienced more difficulty in controlling the codling moth on these 
than on any other commercial varieties. 
In the spraying experiments described an attempt was made to 
time the spray applications according to the development of the 
codling moth as indicated by the life-history studies and field obser- 
5 Siegler, E. H., and Plank, H. K. The Life History of the Codling Moth in the Grand Valley of Colo- 
rado. U.S. Dept. Agr. Bul. 932. 1921. 
6 Quaintance, A. L., and Geyer, E. W. Life History of the Codling Moth in the Pecos Valley, New 
Mexico. U.S. Dept. Agr. Bul. 429. 1917. 
7Hammar,A.G. Life History Studies on the Codling Moth in Michigan. U.S. Dept. Agr. Bur. Ent. 
Bul. 115, Pt.1. 1912. 
