August, '10] DAVIDSON: CALIFORNIAN APHIDIDAE 377 



Aphis ceanotlii Clarke. On tips of twigs of Ceanoilius cuneatus. 



Aphis lutescens Monell. Taken in great quantities on milkweed 

 (AscJepias mexicana). 



Aphis cratagifolice Fitch. Found in the fall in large numbers on 

 the leaves of Cratcegiis oxycantha planted along the sidewalks in the 

 towns of San Jose and Palo Alto. I could not find any alate forms 

 T3ut procured a large number of the black, oval, shining ova whence 

 hatched the first spring brood of larvae. I kept the twigs in water 

 and noticed the first larva emerge on the 7th of February just as the 

 T)uds were swelling. A week later a dozen larvae had hatched. The 

 young are paler than the adults and feed on the opening buds. Alate 

 forms appeared in April. 



Aphis nerii Kalt. This insect was taken in Sonoma County on 

 oleander. 



Aphis bakeri Cowen (?). A doubtful species on Senecio vulgaris. 



Aphis mali Fabr (?). A species very similar to A. mali on the 

 terminal leaves of Laurus laurustinus, causing them to curl. 



Hyalopterus arundinis Fabr. On the plum in great quantities 

 in May. 



Siphocoryne avence Fabr. Sparingly attacking wheat and oats. 



Siphocoryne sal ids Monell. This is not a common insect but it 

 sometimes occurs in large numbers on single trees. 



Siphocoryne xylostei Schrank. Taken iu abundance on the terminal 

 leaves of the cultivated honeysuckle (Lonicera sp.) where it curls the 

 foliage and renders the plant very unsightly. Syrphid larvae prey 

 extensively on it. 



Siphocoryne foeniculi Pass. Taken in November on fennel {Foeni- 

 culum vulgare). Quite generally parasited by a Braconid. 



Siphocoryne conii Davidson. Throughout the year feeding on 

 Conium maculatum. It prefers the flowers and seeds to the leaves. 

 Parasitized by an Aphidius. 



DrepJianosiphum platanoides Schr. This most interesting insect 

 occurs in the summer and fall upon the European sycamore {Platanus 

 orientaUs). I have not been able to locate the eggs during winter, 

 notwithstanding the fact that oviparous females were very common 

 in November. The oviparous female is peculiar in having its ovi- 

 positor protruding considerably. 



Bhopalosiphiim tidipce Thos. On leaves of tulip (Tulipa). 



Bhopalosiphum nymphaece Linn. Common on Polygonum sp. 



Rhopalosiphum violce Pergande. A beautiful insect which occurs 

 on leaves of cultivated violet, generally on the under side. 



Rhopalosiphum lactucce Kalt. At first I thought this insect was 

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