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 Au<»;ust 17 we again sprayed the trees, using this time an enuil- 

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

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

 quantities used, and the AAdiole diluted fiA^e times. At this spraying 

 the trees Avere very thoroughly drenched, the spray being directed 

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

 of the trunk, Avhere the larvte had gathered in the crevices. Even 

 with this emulsion Ave found it somcAvhat difficult to moisten the egg 

 masses, oAving to the Avax. 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 Avith the emulsion. 



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

 appeared to l)e dead. Some of the leaves shoAved a little injury, as if 

 from the enndsion, but it is often difficult to determine Iioav much to 

 attribute to the spray and how nnicli to the insects. 



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

 if Ave use kerosene enndsion 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. Sanborn, CoIIci/c Htalioii. Tex. 



The description of any sjDccies of Aphidida' 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 Avith inclusive dates of infestation. 



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

 concerning the specific names in the family Aphidido'. It seems that 

 early in\^estigators supposed that every species of aphitle colonized 

 but one species of plant. Furthermore, the descriptious 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. 



NoAv it is necessar}^ to knoAv the scientific names of the plants on 

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

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

 host plant is not ahvays 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 



