SOME VARIATIONS IN THE WINGS AND ANTENNA 

 OF TRIFIDAPHIS RADICICOLA Essig 



E. O. ESSIG 



The winged form of Pemphigus radicicola as described in the Pomona 

 Journal of Entomology, March, 1909, page 8, and later classified as 

 Trifidaphis radicicola by G. Del Guercio in the October number of the same 

 Journal, was described from one rather imperfect specimen. During the 

 entire spring and summer of 1909 a constant search was maintained with 

 the result of finding but one winged form. The apterous forms were obtained 

 in abundance. 



On the 13th of April, 1910, while in a lemon orchard at Oxnard, I chanced 

 to pull up a nightshade which was infested with this Aphid. One winged 

 form remained on the roots. Digging into the ground where the plant grew, 

 I was able to obtain some hundred winged specimens from this single plant, 

 to say nothing of the many apterous individuals. In pulling up the plant 

 the winged forms are scraped off because of the friction caused by their 

 wings and remain in the ground. 



Thus with a goodly number of specimens I have been able to note some 

 interesting variations in the wings and antennas in particular. In all over 

 fifty individuals were mounted and studied with results which might be 

 expanded even more, in the future. These results have been recorded in 

 the form of drawings which are presented with this article (Fig. 110). 



Variations in the wings (Compare Fig. 110) : In order to have some 

 system in presenting this material I shall take each vein and make note of 

 its particular variations. 



Cubitus or Sttbcostal. Normal in all wings. 

 Radius or Stigmal. 



A. Slightly curved and not touching the stigma. 



B. Sharply curved near stigma, from which it arises. 



C. Short, sharp curve from stigma, from which it rises. 



D. Well rounded curve near stigma, from which it rises. 



E. Indefinite curve from stigma to tip. 



H. Normally curved and arising from stigma. 



G. Normally curved not arising from stigma. 



H. Normally curved and arising from stigma. 



I. Normally curved and arising from stigma. 



J. Normally curved and arising from stigma. 



Obliques or Discoidals. These veins are somewhat confusing What is 

 present I believe to be as follows : First and second obliques arising from or 

 near the same point and diverging towards the margin ; third oblique, of which 

 but a remnant is present. I believe this to be the third because in one wing 

 of one specimen (h) there is a remnant uniting with this to form a fork. 



