NATIONAL COUNCIL OF HORTICULTURE 27 



Resistant Varieties. Entomologists' have given but little attention 

 to the selecting or breeding of varieties of plants, resistant or unpal- 

 atable to insects. A few examples may be cited as indicating possibili- 

 ties along such lines of work. The solution of the grape phylloxera 

 problem of France and California has come about by the use for graft- 

 ing stock for the European grape of the roots of American vines. 

 Numerous observers have commented on the relative freedom from the 

 woolly apple aphis of apple trees grafted on roots of the Northern Spy, 

 and certain other varieties. Doctor Webber found that one of his citrus 

 creations, the Drake star orange, was resistant to the Phyptoptus rust 

 of the orange. Orton has found that a variety of cow pea, the "Iron," 

 is immune to attack from the so-called root knot, a nematode affection 

 of the peach and many other plants, especially troublesome in the light 

 sandy soils of the South. The comparative immunity from attack by 

 the San Jose scale of Kieffer and Le Conte pears, the quince and sour 

 cherry, is unique in view of the almost omniverous habits of this insect, 

 and the determination of the reason might be of practical value. Cer- 

 tain strains of plums, especially the Americana group, are but little 

 injured by the plum curculio, and varieties of apples vary considerably 

 in regard to susceptibility to codling moth injury. This practically 

 untrodden field should receive more attention from entomologists. 



Mechanical Methods. Only brief reference is required to what may 

 be termed mechanical methods in fighting insects. Under this caption 

 may be included such practices as worming for borers, jarring for 

 the plum curculio, destroying insects by hand picking, etc. In general 

 such methods are resorted to because no better plan is available. Some 

 first-class pests at present must be treated in these ways, though future 

 discoveries may afford more practicable treatment. 



Legislation. The advent into the East of the San Jose scale was 

 the primary cause of the adoption by many states of laws designed to 

 prevent its distribution on nursery stock and secure its eradication or 

 control where established in orchards. Numerous other insect and 

 fungous pests were brought under the operation of the laws, and on the 

 whole the legislation has been productive of great good. That it should 

 uniformly secure the results desired was perhaps more than should 

 be expected. A recent census of insect legislation in the United States 

 shows that only eleven out of the forty-eight states and territories 

 are yet without crop pest laws, and some of these will present bills for 

 enactment shortly. Thirty different insect species are specified as nox- 

 ious pests, and provision in many laws is made for the designation of 

 other insects when deemed expedient. The San Jose scale is the only 

 species mentioned common to all laws, which well illustrates the diver- 

 sity of requirements of the various states. For some years, represen- 

 tatives of the National Nurserymen's Association and of the Official 

 Horticultural Inspectors have endeavored to devise a more uniform 

 system of certification of nursery stock for interstate shipments which 

 is greatly to be desired. So far however, no arrangement has thus far 

 apparently been effected. The establishment of a quarantine and inspec- 



