This is perhaps the most destructive insect pest attacking the apple. Every year, that we have a good apple crop, there are thousands of bushels of wormy apples which are practically worthless. This means an actual loss of thousands of dollars a year to the apple growers of this country. For this reason alone each child should come to know the life history, habits and injury of this pest. It is most destructive to the apple though the pear comes in for its share.

Every country child and many of those of the cities, are familiar with this worm for they often bite into it while eating apples. The small worms crawl down in the blossom end of the young developing apple and from there bore into the pulp and eventually reach the core of the fruit. They stay in the apple about six weeks when they eat a hole out to the surface and crawl down to the trunk where loose bark offers a hiding place. Here they spin their cocoons and change to a small, brown, plump pupa and after a few days the winged moth emerges. The moth is very small and is not often found by one not acquainted with it. They come out during late June and early July when they lay eggs for a second colony of worms which again enter the fruit and destroy more of it. These worms of the second brood are usually mature and leave the fruit about the time apples are picked in the fall in central Missouri. They escape and soon spin cocoons in which they pass the winter. Early in the spring these change to pupae and later the moths come out. They appear about the time apples bloom in the spring and lay the eggs for the first worms which enter in great numbers at the blossom end.

This in short, is the life story of the pest through the year. Little can be done to destroy the pest after it gets into the fruit, therefore remedies must be applied to destroy the worm before it gets into the fruit. All orchards should be sprayed with a poison in the spring before the worms appear. Since most of them enter by way of the blossom end, it is necessary that the poison be put into the blossom end. To do this spray at once after the blossoms fall, repeat after two weeks and spray again in July to kill the second brood of worms. The protection of woodpeckers and sapsuckers will also help as they feed on the worms under the bark.

Observations and Breeding Work

Go into the orchard and examine for apples with masses of sawdust-like material projecting from the sides or blossom end. By removing this brown deposit which is the excrement of the worm, you will find a hole leading into the apple. Cut open one of these and determine the course of the tunnel. Where do you find the worm? Do all such apples contain worms? Where have they gone? How does the feeding of the worms injure the fruit? Do any of the wormy apples show rot? Are any of the windfalls in the orchard wormy and if so what proportion?

Remove a worm from one of the apples and examine it. How many legs has it? What color is it and does it have hair upon its body? Can it crawl fast? Does it spin silk? Put a number of the large worms in a jar and examine from day to day and keep records of what happens. Collect a number in the fall and keep them in a box outdoors during the winter. In the spring watch them change to the pupa in the cocoon and a little later the mature insect or codling moth, as it is commonly called, will emerge. Describe the moth and pin a number of them for your collection. What time in the spring do the caterpillars change to the pupa and when do the moths emerge? If you keep the moths in a bottle they will lay their small circular flat eggs where they can be seen by looking closely. During the winter examine under the bark of apple trees and in cracks and crevices about apple pens for the small silk cocoons containing the worms. Examine in the same places in the spring about apple blooming time and then in place of the small pink worms you will find the small brown pupae. Keep these a few days and the moths will appear.

What proportion of apples in your region are wormy? What are they used for? Are the trees sprayed just after the blossoms fall to control the pest? Where spraying is carefully done, are there as many wormy apples? Why not spray all the orchards properly and have no worms?

Draw and describe the different stages of the apple worm or codling moth and its injury to fruit.

—Tennyson.