376 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 3 



which has certain affinities with this species and may be the same. 

 Only apterous forms were seen. On Salix. 



Ckaitophorus negundinis Thos. I took this insect in considerable 

 abundance on the under side of leaves of Acer negundo in April. 

 Both alate and apterous forms were present, but I could not find any 

 males so early in the year. On the day on which I first noticed the 

 aphid there were a few large yellow wingless forms which were pre- 

 sumably stem mothers left over. Towards the end of this month I took 

 a number of the pale leafy dimorphs. 



Pliyllaphis fagi Linn. One specimen, an apterous female, taken on 

 the under side of a copper beach at Palo Alto in April. 



Idiopterus neplirelepidis Davis. On greenhouse ferns. Probably 

 imported from the tropics on ferns. The insect was collected here 

 some years ago but is not to be found at the present time. 



Callipteriis castanece Buck. On chestnut {Castanea). 



CalUpterus betidcecolens Fitch. On Betula sp. 



Callipterus caryce Monell. On cultivated walnut. 



CalUpterus arundicolens Clarke. On bamboo {Arundo). 



CalUpterus ulmifolii Monell. On Ulmus americana. 



Callipterus tilice Linn. On Tilia americana. The stem mothers in 

 spring are very pale and immaculate. 



CalUpterus quercus Kalt. I am sceptical as to the identity of this 

 Callipterus found at Palo Alto on both the blue oak {Quercus 

 douglasii) and on the white oak {Quercus lohata). It seems very near 

 Kaltenbach's species, having the three pairs of tubercles on the dorsum 

 and otherwise resembling it. I cannot satisfactorily compare it to 

 any described American species. There are several English oaks near 

 the trees infested and on one of these I found a very pale Callipterus, 

 apparently C. quercus. Thus it is possible that the insect came on 

 the young oaks when they were imported. However, I found this 

 same species on the black oak {Q. calif or nica) on the hills around 

 San Jose where I found no English oaks although some doubtless 

 existed in the valley towns below. 



Aphis albipes Oestl. Found in April on the tender stalks and in 

 curled leaves of the snowberry {SympJiorlcarpus raceniosus). A 

 striking insect much preyed upon by Syrphus flies. 



Aphis hrassiccB Linn. Common everywhere but checked, success- 

 fully at least in Santa Clara County, by its parasite Diceretus cali- 

 fornicus Baker. On cruciferous plants. 



ApMs rumicis Linn. Taken on the terminal shoots of ivy. An 

 extensively parasitized species. 



Aphis medicaginis Koch. On Medicago deriticulata. 



