168 INSECT EAVAGBS. 



replace those altogether tlostroyed. Even in trees newly planted, shoots 

 will often come up from the roots, where the main stem has been killed.' 



As for remedies against grasshoi)per8, but few are found effectual. In 

 several instances we have known of these insects being hindered from 

 alighting upon a nur?ery of young trees by raising clouds of smoke on 

 the windward side as they begin to appear on the wing. Where they 

 are hatched upon the spot, and before the insects have acquired wings, 

 they may be hindered li'om climbing the trees by fastening shields ot 

 tin, or locks of cotton around the trunks, or by smearing the trunk sev- 

 eral inches with coal tar, or a wash of chloride of lime, copperas, and 

 turpentine. But these precautions are of course applicable only in ex- 

 ceptional cases. 



With respect to the influence of tree planting as a means for prevent- 

 ing the breeding of these insects, we have many facts to justify the 

 theory that in a country properly interspersed with timber and groves 

 of young trees the climatic conditions arc unfavorable for their increase; 

 and so far as concerns the damage that may bo done by those hatched 

 in such regions, that they would be no greater than those sometimes 

 felt in dry seasons in the older sections of the country where grasshop- 

 j)ers have always been seen, but their ravages seldom severely felt. 

 The clouds of these insects that come upon the wing, are bred in treeless 

 and arid distriets, and never in a country interspersed with groves and 

 timber belts. There is some evidence to show that they prefer such 

 treeless regions when they alight, and that they avoid woodlands where 

 open fields are near. 



MEANS FOR DESTRUCTION OF INSECTS INFESTING TREES. 



Among the methods practiced with success for the destraction of in- 

 sects ui)on fruit trees, and applicable to forest trees, may be mentioned 

 the following: 



Building fires in the evening, to attract miliars and other insects, 

 which fall into the flames and perish. 



Jarring the trees by striking them with a heavy piece of scantling, 

 padded at the end to prevent injury to the bark. Cloths should be 

 spread under the trees to catch whatever falls. Some caterpillars that 

 spin down on a silk fiber, may be swept down with a broom and de- 

 stroyed. 



Smearing the bark with tar, molasses, or printer's ink, or other viscid 

 substance, or what is better, wra{)ping papers or cloths around the 

 trunk, and applying the tar to these instead of the bark. The sub- 

 stance should be renewed as it becomes dry.^ 



Surrounding the trunk with leaden troughs filled with oil, coal tar, 

 or other liquids. Applying discs of tin that, sloping downwards, ])re- 



'Ai^artof the dama<^<-8 charged to grasshoppers in Kansas and Nebraska in 1^74 

 was secondary, and was caused as follows : The defoliated trees, under a warm, wet, 

 growing autumn that followed, put forth new foliage, and many trees blossomed late 

 in the season. Ttiis was followed by severe cold in winter, which loosened the bark 

 and killed the young wood before it had consolidated so as to endure the frost. 



-A band of tar, 1.5 to 20 centimeters (6 to 8 inches) wide, renewed two or three 

 times in the season, has been found an eftoctual safeguard against theegger-raoth {La- 

 aiocampus). The band is painted on at about five feet from the ground, the roagh 

 bark being first smoothed o(F. It should b^ done early in the spring, just as the insect 

 begins to develop at the root of the tree. Several hundred thousand thalers have been 

 expended in Germany for this object. An hectare of pine requires the labor of a man 

 from three to eight days to smooth the bark, and from two and a half to seven to 

 apply the first coat of tar. It is renewed in about half this time. The amount re- 

 quired is from 18 to 40 liters for the first, and from G to 20 for the Becond application. 



