252 EXPERIMENT STATION RECORD. 



larva. " Even the most-advanced caterpillars do not mature imtil well along 

 in June, while some of those that hatchetl very late do not complete their growth 

 in time to transform the first season, but lie over a second winter, practically 

 full grown, and do some little feeding at the beginning of the next summer. 

 ... No cocoons at all were found, in 1910, on June 24 ; July 8 they were to be 

 found in some numbers, and on July 13 moths had begun to emerge, making 

 an extreme of 19 days, of which perhaps 15 may be credited to the actual pupal 

 stage." 



Every tree set out should be closely examined for signs of the borers or 

 borer work and every tree that may have a borer in it discarded. "An existing 

 or already infested orchard should be carefully examined at least twice in each 

 year ; as late as convenient in fall, and again in the following end of May or 

 early June. In the fall examination the earth should be removed from around 

 the base of the trees to a depth of at least 6 and preferably 8 inches and every 

 sign of a wound or place from which gum exudes should be investigated." 

 Examinations should again be made between the end of May and the middle 

 of June, by which " time the borers that wintered in the second or third stage 

 will have reached the fourth stage at least and will show signs of their presence 

 even if pretty well down. Their feeding will not have been sufficient to have 

 caused serious harm, and careful work at this time should result in the 

 elimination of at least 95 per cent of all the borers present in the orchard. 

 Leave the base of the tree exposed for a few days now, to toughen the outer 

 bark, and then, before again drawing up the soil, spray very thoroughly with a 

 lime-sulphur, arsenate of lead mixture, to which an excess of lime has been 

 added. Use 1 pound paste arsenate of lead to every 5 gallons of lime-sulphur, 

 or 1 pound of dry arsenate to every 10 gallons of lime-sulphur, and apply with 

 all the force possible to the exposed crown and for a distance of 18 to 24 inches 

 above the surface. Then cover and hill up at least 6 inches around the trunk 

 after the application is thoroughly dry. The strength of the lime-sulphur wash 

 may be that of the ordinary winter spray with double the required amount of 

 lime. . . . The lime and sulphur will weather above groimd and may carry 

 with it the arsenate of lead ; therefore, it seems desirable to make at least two 

 additional applications to the trunk above ground, say one about July 10 and 

 the other about August 1. Below ground the soil and moisture will maintain 

 the poisonous coating for the entire season." 



As a result of observations and experiments made during the seasons 1909 

 and 1910 and after going over records of previous experiments, the author 

 concludes that mechanical coverings of paper and other materials are not of 

 sufficient value to be further recommended. It is pointed out that a protective 

 covering must be in place not later than July 1, and must be maintained intact 

 until September 1 at least, if all borers are to be excluded. The various com- 

 binations of clay, lime, cowdung, soap, and other messes are all good if they 

 can be applied well enough and cheaply enough to aflord complete protection. 



Egg-laying by the plum curculio begins in south Jersey by May 10. The 

 eggs hatch in about a week, and the larval galleries and young larvae may be 

 found in dropped fruit any time from May 20 to early July. The heavy part 

 of the brood matures in mid-July as larvse and during early August as adults. 



The terrapin scale is confined to Cumberland County, where it is more injuri- 

 ous than the San Jose scale and has led to the abandonment of oi-chards in 

 some instances. The black peach aphis occurs throughout the State, but does 

 injury only in warm light soils and mainly during the early life of the tree. 

 The green aphis, which is always present to some extent everywhere in the 

 State, only becomes seasonally and locally troublesome on younger trees. The 

 peach twig borer has been found by the author throughout the State, and in 



