ALBERT F. SWAIN 17 



and six families. According to Davidson "on German ivy it 

 seems to exist the year around, the annuals being infested by 

 migrants from it." The writer has noticed this in the San Fran- 

 cisco Bay region, but in Southern Cahfornia it is found during 

 the winter, particularly on asters and marigolds. When the hot 

 weather of the summer in the south begins, it seems to disap- 

 pear, not being found again until fall. In the early part of the 

 year (January and February) the alates are most common, the 

 apterae appearing later. Following is a list of the host plants 

 and collection records: 



Food Plants 

 Salicaceae. Willow family. 

 Salix sp. (willow). Berkeley, Essig, 1915. 



Polygonaceae. Buckwheat family. 

 Rumexsp. (dock). Stanford University, March, 1915, apterae.'" 



Leguminaceae. Pea family. 

 ■Cytisus proliferus (broom). Berkeley, Essig, 1915. 



Malvaceae. Mallow family. 

 Abutilon sp. (Indian mallow). Stanford University, Februar}', 1915, apterae. 



Boraginaceae. Borage family. 



Ambrosia psilostachya (western ragweed). Berkeley, Essig, 1915. 



Amsinckia sp. Stanford University, Davidson, 1909. 



Amsinckia intermedia (buckthorn weed). Stanford University, Morrison, 



1912. 

 Amsinckia spectabilis. Berkeley, Essig, 1915. 



Compositae. Composite family. 



Anthemis sp. (chamomile). San Francisco Bay region, Davidson, 1914. 



Artemesia sp. (sagebrush). San Francisco Bay region, Davidson, 1914. 



Artemesia calif ornica (old man). Berkeley, Essig, 1915. 



Artemesia heterophylla (California mugwort). Berkeley, Essig, 1915. 



Aster, cultivated. San Diego, January, 1916, alate; Ontario, San Bernardino 

 Coimty, January, 1917, alate. 



Baccharis pilularis (chapparal broom). Berkeley, Essig, 1915; Stanford Uni- 

 versity, Ferris, 1916. 



■Calendula officinalis (marigold). Berkeley, Essig, 1915; San Diego, March, 

 1916, apterae; Riverside, February, 1917, alate; Orange, Orange County, 

 February, 1917, alate and apterae. 



'"In references where no collector's name is given the collection was made 

 by the writer. 



TRANS. AM. ENT. SOC, XLIV. 

 2 ■ 



