Along early in April these eggs, warmed by the same sun that swells the buds and causes the green tips of the leaves to protrude, hatch into tiny worms looking like a dark thread snipped into bits about an eighth of an inch long. These millions of tiny worms, scarcely visible, occupy their time eating and growing, and the orchardist is possibly unaware of the army he is feeding until they grow into lusty, fat worms, from one and one-eighth to one and one-fourth inches long, of a dark olive-green color, with black heads. See a, [fig. 4]. If disturbed they quickly spin a single web and fall suspended at its end, as in [fig. 1]. Their life, as worms, lasts only about six weeks, then they seem suddenly to have vanished. They have gone into the earth to pass into the pupa state, coming out the following spring as adults; the males with wings to fly, the female wingless, as in [fig. 2], to crawl up the tree as described. Now, as these myriads of tiny worms must make the tons of grown worms entirely from the foliage on the trees in which they hatched, it is plain that the said foliage must suffer, and it will look as if scorched by fire.
Remedies. Bands smeared with sticky material put tightly around the tree bole early in February has stopped many a female from crawling up to lay her eggs. Spraying with London purple or Paris green, one pound with two pounds of lime and 150 gallons of water, is the common remedy. To be efficacious the drug must be of a normal strength, say forty-five per cent. arsenic, and as the worms grow larger and stronger the water must be lessened. When the worms are an inch or more long it may require only fifty gallons of water. Another formula is, two pounds white arsenic, four pounds sal soda, two gallons of water; boil until the arsenic is dissolved. One pint is enough for forty gallons of water. As the worms usually feed on the under side of the leaves, spraying should be from below as much as possible. "The early bird catches the worm" is true here. Therefore, spray while the worms are tiny and the foliage thin, and the work will count as the "stitch in time," destroying nine hundred and ninety-nine.