Vol.1] 



Essig. — Aphididae of Californm 



343 



the immature form of a white fly than for an aphid. The young 

 apterous viviparous females are dark or pale brown and when 

 mature acquire a white fringe around the margin as shown in 

 the illustration (fig. 26). The winged forms are dull brownish 

 or blackish in color. The species occurs in greenhouses through- 



#■'■• .'Jf ' 



Fig. 26. CcratapMs latanUu ( I'.uisdux ;ilj. Apterous viviparous females 

 on leaf of orchid. Oakland, Gal., July 25, 1916. (Original.) 



out this district and sometimes becomes a pest to orchids. Taken 

 on orchids, Oakland, California, July 25, 1916. 



Pemphigus popuJitransversus Riley (figs. 27 and 28). The 

 fundatrix is pale amber or yellowish with tufts of white cottony 

 material arranged in rows on the dorsum. The virgogeniae are 

 black with more or less cottony material at the posterior end of 



