August, '15] 



DAVIDSOX: WESTERN PLAXT-LICE 



421 



at the base of which to settle. After a few days the petiole begins to 

 swell at the point of attack and the gall gradually proceeds to form 

 about the growing louse. If the wrong species of poplar is selected by 

 the sexuparse for depositing the sexes, the fundatrix will hatch from 

 the winter egg but will not feed successfully on the foliage and finally 

 will die without having shown any appreciable growth. 



I have bred a Syrphus (Pipiza pisticoides Will.) from a larva 

 found feeding upon the sexuals of this aphid. 



The winged spring migrants (funditrigenia) in the latitude of San 

 Francisco may be found in the galls from May to November. The 

 alternate host-plant is as yet unknown to me. 



Prociphilus fraxini-dipetaloe Essig 

 Pemphigus fraxini-dipetaloe Essig; Essig, Pomona College Journal of Entomology, 

 III, 3, Sept. 1911. 



What I am inclined to consider as the sexuparse of this species were 

 taken under the bark of ash (Fraximis oregana) March 16, 1915. On 

 that date the sexuparse were all dead and dried up and nearly all the 

 winter eggs had hatched. The young reddish stem-mothers occurred 

 higher up on the tree either in cracks of the limbs or on the expanding 

 foliage and excreted much cottony substance. On March 26, many 

 of these stem-mothers were mature and were undoubtedly Prociphilus 

 fraxini-dipetalce, so that it would appear reasonably certain that the 

 dead sexuparous migrants below were of this species in spite of the 

 marked difference in antenna! characters between them and the winged 

 spring migrant. This difference in antennal structure between spring 

 migrants and fall migrants is very noticeable among the Pemphiginse. 

 The spring migrants of P. fraxini-dipetalce have been taken both on ash 

 and olive and occur almost all over California. They have joints III 

 and IV of the antennae sensoriated while the fall migrants from ash 

 bark have all 4 of the principal antennal joints with sensoria. From 

 the dried up specimens of sexuparse the following notes were taken: 

 Costal and subcostal veins black, prominent; other veins with rather 

 indistinct light brown smoky borders. Legs black. Thoracic wax 

 glands as in Prociphilus. Antennae III, .37 to .42 mm.; sensoria 14 to 

 17; lY, .18 to .27 mm.; sensoria 5 to 11; V, .19 to .23 mm.; sensoria 6 to 

 7; VI, .18 to .20 mm. (unguis .04 besides); sensoria 5 to 6. Length 

 of wings about 4 mm. Place of collection, Walnut Creek, Cal. 



This species may perhaps prove synonymous with Prociphilus vena- 

 fuscus Patch. 



Euceraphis gillettei sp. nov. 

 Winged viviparous female. — General color pale apple green. The majority of 

 individuals are quite bare but some of those of the later generations secrete a scanty 

 amount of greyish-white flocculence. Antennae much longer than the body, on frontal 

 3 



