6 
Colorado Explrimlnt Station 
brood, and 40 to 50 percent of the second enter the calyx as soon as 
they hatch from the eggs. The larvae feed in the fruit for about 
21 days, then crawl down the tree to hide while they pupate and 
change to moths. There are two broods a year in Colorado. It 
takes about 50 days for one complete generation to develop from 
egg to egg or moth to moth. See Plate i. 
PLATE 1.—Codling Moth in its different stages: a, eggs upon a leaf; a 1, eggs natural 
size, 1 a, eggs much enlarged; upper 1 a, a newly laid egg; middle 1 a, the appearance of the 
egg after 4 or 5 days showing the flesh-colored ring of the embryo; lower 1 a, showing the 
outline of the small larva, the dark spot being the head (an egg in this stage woud hatch 
in a day or two) ; a 2, eggs parasitized by Trichogramma minutus, a very small 4-wingcd 
fly that deposits its eggs within those of the codling moth; 2,a, parasitized codling moth 
eggs much enlarged, showing holes made by the parasites as they leave the eggs; upper 2 a, 
side view of parasitized egg; b, egg natural size upon an apple; c, codling moth larva; d, 
codling moth; e, chrysalis or puna; f, cocoon and chrysalis. Figures al and a2 and b, natural 
size; 1 a and 2a, enlarged 10 times; c, d, and e, enlarged 2 times; f, enlarged times, 
Original, Miriam A. Palmer, Delineator. 
Remedies .—Remedies 2, 4, 5, and 29 are used against this pest. 
The arsenical poisons are most effective, and of these arsenate of 
lead is most generally used, in the proportion of 3 to 4 pounds, of 
the paste to each 100 gallons of water. As a large percent of the 
Httle worms enter the calyx of the fruit, it will readily be seen that 
careful attention should be given toward destroying these. The sole 
purpose of the first spray is to get poison into the calyx cups that 
these little worms will be poisoned as they try to enter the apple. 
This spray should be applied just after the blossoms fall, and before 
the calyx lobes close. There are only a few days when the fruit 
is in the proper condition to receive this spray. Continue the appli¬ 
cation until every calyx is filled with the liquid. Large trees will re¬ 
quire from 8 to 16 gallons for a thorough treatment. See Figs, i and 2. 
Much has been written in regard to the so-called one-spray 
method of controling the codling moth. It consists in putting on 
this first spray very thoroughly. This seems to be sufficient in 
