APPLE INSECTS — BUDS AND FOLIAGE 103 



and Euphorocera daripennis. Unfortunately, however, there 

 are 14 hyper-parasites which work on the true parasites and 

 thus materially lessen their effectiveness. There are also ter- 

 tiary parasites which destroy these hyper-parasites, thus pre- 

 senting a very complicated and interesting case of insect 

 parasitism. 



Remedial measures. 



A practicable and effe(;tive method of controlling this pest is 

 to collect and burn the eggs in autumn or winter. The grayish 

 egg-masses are quite conspicuous on the bark and they are often 

 attached to a dead leaf or two fastened to the branches. Where 

 shade trees are infested in cities, it will pay to employ laborers 

 to collect the eggs, and sometimes the school children can be 

 induced to do very effective work by offering prizes or by paying 

 liberally for certain quantities of the egg-masses. The latter 

 method was employed successfully several years ago in Rochester, 

 N. Y., during a severe outbreak of the pest. 



Before they are half-grown the beautiful caterpillars will 

 succumb to thorough applications of a strong poison spray, such 

 as Paris green (1 pound in 100 gallons) or arsenate of lead (5 or 6 

 pounds in 100 gallons). One or two applications of such a spray 

 will usually control this pest. Later when the caterpillars are 

 larger, the poison is not so effective. As the caterpillars drop 

 to the ground by a silken thread when the tree is jarred, some 

 orchardists have found it practicable to capture them on cur- 

 culio-catchers or sheets. Or after jarring them off, they can 

 be prevented from ascending the trees by means of a sticky 

 rope band around th(^ trunk. Treat the rope with a tangle- 

 foot mixture of resin and (uistor oil, as recommended for canker- 

 worm bands. 



References 



U. S. Bur. Ent. Tech. Bull. 5. 1897. Parasites. 

 U. S. Farmers' Bull. 99, pp. 14-31. 1899. 

 Del. Agr. Exp. Sta. Bull. 56, pp. 9-18. 1902. 

 N. Y. (Geneva) Agr. Exp. Sta. Bull. 312. 1909. 



