172 DESTRUCTIVE INSECTS. 



The moths of the fall canker-worm and of the two last* 

 named species emerge in the fall, while the spring canker- 

 worm moths appear in March and April. In each case the 

 wingless females have to crawl up the tree, where they lay 

 their eggs on the bark. The eggs of each species hatch about 

 the same time in the spring, as the leaves begin to unfold, 

 and the caterpillars feed ravenously for about a month. They 

 then disappear into the ground a short distance, where they 

 transform to pupse, finally to emerge as moths in the fall or 

 spring. 



Canker-worms are not difficult pests to control when one 

 understands their habits, so that the warfare can be waged at 

 the proper time. The caterpillars can be killed after they 

 have begun work in the spring by thorough, honest efforts 

 with a spray of Paris green or some similar poison at the rate 

 of one pound in one hundred gallons of water or Bordeaux 

 mixture. It will require several applications where the pests 

 are very numerous, and it is all-important to apply the poison 

 before the caterpillars get two-thirds grown ; it always takes 

 much less poison to kill a small caterpillar than one nearly 

 full-grown. 



Orchards which are well cultivated from year to year are 

 rarely seriously infested with canker-worms. Doubtless many 

 of the pupae in the soil are destroyed by the cultivation. 



As the female cannot fly, various expedients for preventing 

 it from ascending the tree from the ground in the fall or early 

 spring have been devised. Bands of sheath- 

 ing-paper six or eight inches wide are 

 often tacked around the trunks of the 

 trees, and then smeared with tar, or any 

 other sticky substance which will not lose 

 its viscidity. Before putting on the bands 

 smooth off the bark, so that there shall 

 be no crevices under the paper through 

 which the tiny moths may crawl. 



Another simple patented device, shown 

 in Fig. 235, has been extensively and suc- 

 cessfully used in Western New York. 

 FIG. 235. Common- This Common-Sense Wire Trap, when 



sense Wire Trap for , ., . , ., , t 



canker-worms. properly put on and cared for while the 



