46 NEW YORK STATE MUSEUM 



where the newly liatchcd caterpillars can find an abundance of sus- 

 tenance. 'l"he spring- form is so called because the females remain 

 in the ground till some time after inidw inter, crawling up the trees 

 during warm weather, even in hebruary though more usually in 

 March. The fall cankerworm is thus designated because the females 

 usually crawl up the trees and deposit their eggs in late fall or early 

 winter. The eggs of both species hatch at about the same time, 

 namely, when the young leaves begin to appear. 



Cankerworms are exceedingly voracious and, when present in 

 numbers, nothing but the most prompt action will be of service in 

 mitigating the trouble. The larvae are somewhat resistant to in- 

 secticides and as a consequence it is advisable to spray at the incep- 

 tion of the outbreak with paris green used at the rate of i pound 

 of poison with an equal amount, by weight, of lime, to 50 to 75 

 gallons of water. The lime is added to lessen the danger of injury 

 by poison. Arsenate of lead can be employed at the rate of i pound 

 to 7 gallons of water, though as it is a slower acting poison, it is 

 usually advisable to apply paris green. The homemade arsenite 

 of lime is equally effective. Ordinarily one application of poison is 

 sufficient, but if this does not prove satisfactory, a second treatment 

 should be given a few days or a week later. 



Cankerworms spread very slowly, owing to the fact that the 

 females are wingless, and as a result the species must depend 

 largely for carriage upon winds and other natural agencies, conse- 

 quently an orchard once freed of the pest is not likely to be attacked 

 for some time. We have yet to hear of a serious outbreak in 

 orchards systematically sprayed from year to year. The ordinary 

 treatment for the control of the codling moth and other leaf feeding 

 insects is usually sufficient to keep this pest under control. Advan- 

 tage may also be taken of its limited means of locomotion and injury 

 prevented by the use of sticky bands, such as Tree Tanglefoot, tar 

 or printers ink. The Tree Tanglefoot is a new material which has 

 come into high favor in eastern Massachusetts where it is used ex- 

 tensively in gipsy moth work. Experience has shown that it can be 

 applied with practically no injury to most trees, and possesses a 

 decided advantage in remaining adhesive for a considerable period. 

 It is advisable, if either tar or printers ink is used, to apply these 

 materials to a band of tarred paper wrapped around the trunk of 

 the tree, rather than to make the application direct to the bark. We 

 much prefer to advise the employment of arsenical poisons, since 

 they are of service in checking other leaf feeders, rather than to 



