162 ASSOCIATION OF ECONOMIC ENTOMOLOGISTS. 



agreed with him. A few of the scales were killed, but most of them 

 seemed to be uninjured by the spray. 



On August 17 we again sprayed the trees, using this time an emul- 

 sion made with a soft naphtha soap and without hot water. Two 

 gallons of kerosene, 1 pound of soap, and 1 gallon of water were the 

 quantities used, and the whole diluted five times. At this spraying 

 the trees were very thoroughly drenched, the spray being directed 

 especially against the under side of the leaves and against the bark 

 of the trunk, where the larvae had gathered in the crevices. Even 

 with this emulsion we found it somewhat difficult to moisten the egg 

 masses, owing to the wax. The first spray striking a leaf usually 

 rolls off in small drops, but if the nozzle is held in one place long 

 enough the mass finally becomes soaked with the emulsion. 



On examining the trees a few days later nearly all of the insects 

 appeared to be dead. Some of the leaves showed a little injury, as if 

 from the emulsion, but it is often difficult to determine how much to 

 attribute to the spray and how much to the insects. 



I am satisfied that this insect is a difficult one to combat, and that 

 if we use kerosene emulsion against it the spray should contain not 

 less than 15 per cent of kerosene. 



THE RELATION OF DESCRIPTIONS TO ECONOMICAL METHODS OF 

 ERADICATION IN THE FAMILY APHIDID^. 



By Chas. E. Sanboen, College Station, Tex. 



The description of any species of Aphididse should contain that of 

 the different apterous and migratory forms, the male, the true or 

 sexual female, the egg, and in addition the scientific names of the 

 host plant or plants with inclusive dates of infestation. 



There has originated and continues to be a great deal of confusion 

 concerning the specific names in the family Aphididse. It. seems that 

 early investigators supposed that every species of aphid e colonized 

 but one species of plant. Furthermore, the descriptions given by 

 these authors are limited mainly to the general color of the insects at 

 the time of their capture, and a common name of the host plant with 

 no date of infestation. 



Now it is necessary to know the scientific names of the plants on 

 which specimens are captured, partly as a ready reference key to 

 species. It must be borne in mind, however, that the name of the 

 host plant is not always a true index for any species. Some species 

 are quite cosmopolitan in their feeding habits and migrate from one 

 host plant to another during the season and are changed sometimes 

 in form, sometimes in color, and sometimes in both color and form. 



Take for instance the common grape leaf-aphis. Soon after it 



