﻿DEL GUERCIO. NEW GENERA OF APHIDS 75 



AA. Posterior wings witli the two oblique veins united at the base, causing the 

 subcostal to appear trificl at the point of division. 



Genus TriMapliis Del Guercio. 



(Sp. tip. Pemphigus radicicola Essig.) 



Trifidaphis radicicola (Essig) was collected for the first time at Santa 



Paula in California in November, 1908, on the roots of Amarantus retroflexus, 



on which we have also found Tctrancura phascoH (Pass.). T. radicicola was 



collected on the roots of Solaiiuiii doui^lasii near Claremont, California. 



