PROTECTING PLANTS 201 



The white maggots that feed on the roots hatch from eggs laid 

 near the plant at the surface of the ground by a small fly somewhat 

 resembling the common house fly. Hollow out the earth slightly 

 around every plant and freely apply carbolic acid emulsion diluted 

 with 30 parts of water. Begin the treatment early, a day or two 

 after the plants are up or the next day after they are set out. Repeat 

 the application every 7 to 10 days until the latter part of May. It 

 has also been found to be practicable to protect the plants by the use 

 of tightly fitting cards cut from tarred paper. (See page 187.) 



Canker-worms. — These caterpillars are small measuring-worms or 

 loopers that defoliate apple trees in May and June (Fig. 217) . The 

 female moths are wingless, and in late fall or early spring crawl up 

 the trunks of the trees to lay their eggs on the branches. Spray thor- 

 oughly once or twice, before the blossoms open, with 1 lb. Paris green 

 or 4 lb. arsenate of lead in 100 gal. of water. Repeat the application 

 after the blossoms faU. Prevent the ascent of the wingless females by 

 means of sticky bands or wire-screen traps. 



Case-bearers on apple. — The small caterpillars live in pistol-shaped 

 or cigar-shaped cases, about i in. long. They appear in spring on 

 the opening buds at the same time as the bud-moth and may be con- 

 trolled by the same means. 



Codlin-moth. — The codlin-moth lays the eggs that produce the 

 pinkish caterpillar which causes a large proportion of wormy apples 

 and pears. The minute eggs are laid on both the leaves and on 

 the skin of the fruit. Most of the caterpillars enter the apple at the 

 blossom end. When the petals fall, the calyx is open and this is the 

 time to spray. The calyx soon closes and keeps the poison inside 

 ready for the young caterpillar's first meal. After the calyx has closed, 

 it is too late to spray effectively. The caterpillars become full grown 

 in July and August, leave the fruit, crawl down on the trunk, and there 

 most of them spin cocoons under the loose bark. In most parts of the 

 country there are two broods annually. Immediately after the blos- 

 soms fall, spray with 1 lb. Paris green or 4 lb. arsenate of lead in 100 

 gal. of water. Repeat the application about 3 wk. later. Use burlap 

 bands on trunks, killing all caterpillars under them every ten days 

 from July 1 to August 1, and once later before winter. 



Cucurbit {cucumber, melon, and squash) insects. — Yellow, black- 



