A SYNOPSIS OF THE APHIDIDAE 75 



abundant as to cause some considerable damage to its host. On March 

 4, 1917, the author observed it on periwinkle in Los Angeles in such 

 numbers as to stunt the flowers and to cause all the plants to appear 

 black and sticky. The apterae of this species are readily recognized 

 by the black horseshoe-shaped marking on the dorsum of the abdomen. 



89. Myzus cynosbati (Oestlund) 



Oestlund, Minn. Geol. and Nat. Hist. Surv., Bull. 4, p. 81, 1887. Nectaro- 



phora (orig. desc.). 



Davidson, Jour. Econ. Ent., vol. 10, p. 294, 1917 (note). 

 Shinji, Can. Ent., vol. 49, p. 49, 1917. M. ribis (Linn.) (list). 



Records. Eibes vulgar e; Walnut Creek (Davidson) ; Eibes glutinosum, E. 

 menziesii; Berkeley, April, 1915 (Shinji). 



This species has been taken but a few times in the San Francisco 

 Bay region; once on cultivated red currant in company with Aphis 

 neomcxicana pacifica, once on wild flowering currant, and once on 

 wild canyon gooseberry. Furthermore, only the sexapura (migrants) 

 and sexuales have been taken. Davidson writes that this is true 

 cynosbati of Oestlund and not the species described by Davis (Ann. 

 Ent. Soc. Am., vol. 2, p. 38, 1909), as Macrosiphum cynosbati (Oest.), 

 which is not that species but some other. Shinji listed M. ribis 

 (Linn.), but his specimens prove to be the sexuales of this species. 



90. Myzus fragaefolii Cockerell 



Figure 177 



Cockerell, Can. Ent., vol. 33, p. 101, 1901 (orig. desc.). 

 Davidson, Jour. Econ. Ent., vol. 7, p. X35, 1914 (desc. sexuales). 



Records. Fragaria chiloensis; Walnut Creek, Contra Costa County (David- 

 son) ; Berkeley, March to September, 1915; Palo Alto, April, 1915; Ontario, 

 April, 1917; Buena Park, Orange County, May, 1917 (E. K. Bishop); Santa 

 Barbara, May, 1917; Eialto, San Bernardino County, May, 1917 (A. B. Snow): 

 F. californicus; Pine Hills, San Diego County, June, 1916. 



On the under side of the leaves of native and cultivated straw- 

 berries this small yellowish aphid is often found, both in the San 

 Francisco Bay region and in southern California. Seldom does it 

 become abundant, although several records of its abundance were 

 received from various parts of the south during the spring of 1917. 

 Several growers have thought it bad enough to spray for it. During 

 the late winter (January and February) the sexuales appear and 

 the eggs are laid. These hatch in a short time, and during the rest 

 of the year the alate and apterous viviparae are found. 



