REPORT OF THE STATE ENTOMOLOGIST IOX)0 967 



EXPERIMENTAL WORK WITH INSECTICIDES 



There has been during the past year a very great demand for precise 

 information as to the best methods of fighting scale insects specially the 

 San Jose or pernicious scale, Aspidiotus perniciosus Comst 

 Very little experimental work had been done on this insect in New York 

 state before this year, and, as this serious pest had become established 

 in several large orchards in the state, and as some owners were having in- 

 different success in combating it, the state entomologist was almost com- 

 pelled to take up this work. This is an exceedingly important matter, be- 

 cause the San Jos£ scale has already showed itself not only hardy in our 

 climate but capable of inflicting very serious damage. The eradication 

 of this insect is now an utter impossibility. The corps of nursery in- 

 spectors of the state department of agriculture have been doing good 

 work in detecting the presence of this insect and in destroying infested 

 trees. In spite of all this, inspection can not, nor does it attempt to, 

 guaranty absolute immunity from the pest. There is always a chance 

 of overlooking a few scales, and that, taken in connection with the greater 

 chance of receiving scale on stock brought from other states, should render 

 every purchaser very careful as to what and where he buys. The 

 presence of this scale insect in orchards of such extent as to render hope- 

 less the extermination of the pest is a strong indication that many fruit- 

 growers will within a decade be compelled to fight this insect on their 

 own premises or lose their crops. This pest has been established near. 

 Albany some eight years or more, and during that period it has suc- 

 ceeded in overrunning a small fruit orchard, where it has killed many cur- 

 rant bushes and a number of trees, besides ruining others. It also oc- 

 curs on adjoining premises, and has become established over so large an 

 area that, even were this the only infested spot in New York state, 

 which is far from the truth, nothing but the most heroic measures would 

 stamp out the pest. The fruit-trees were young, and, owing to the ac- 

 cessibility of the place, it was very good for experimental work in 

 orchards. There are comparatively few trees grown in the vicinity of 

 Albany, and, therefore there is little or no opportunity for work under 

 conditions obtaining in a nursery, though some of the results are as 

 valuable to the nurserymen as to the orchardist. 



The experimental orchard is a rectangular piece of ground about 75 

 by 475 feet. It is a rather light loamy strip extending over a slight knoll 

 and having a southwestern slope toward the Hudson river. The general 

 position of the trees, their size, variety and degree of infestation are 



