83 



leaf hoppers in general, and should prove effective here also, 

 the difficulties in its use being the same as with plant lice, viz., 

 that the insects must be actually touched by the spray if they 

 are to be killed, and that they are very small. Only thorough 

 spraying, using every effort to reach the under side of the 

 leaves where most of the hoppers are found, will give satis- 

 factory results. The strength of spray to use is the same as 

 that advised for plant lice above. 



Caterpillars. 

 Numerous caterpillars are found feeding on apple leaves, but 

 in the majority of cases spraying with arsenate of lead as 

 soon as they are noticed will quickly kill them. Among the 

 common kinds noticed is the tent caterpillar, which goes out 

 each morning from white webs or tents spun in the forks of 

 branches during the spring. Spraying with arsenate of lead 

 will easily control this pest, and a special treatment for it is 

 usually unnecessary if the codling moth treatment given below 

 is carried out; The gypsy moth and brown-tail moth cater- 



Yellow-necked apple-tree caterpillar: a, caterpillar, showing char- 

 acteristic position when disturbed ; &, adult moth; c, cluster 

 of eggs, natural size; d, side view of one egg much enlarged. 



pillars are also often abundant on the trees during the spring 

 months, at least in Eastern Massachusetts. All of these 

 spring-feeding caterpillars can be kept under control by spray- 

 ing once or twice. If the fruit grower is on the alert to dis- 

 cover them as soon as they begin work, and treat them before 

 they have had time to do much harm, he' need not fear much 

 injury to the trees by them. 



In August or even early September other caterpillars are 

 liable to appear on the trees. Some, such as the yellow-necked 



