452 
The economic importance of this pest is greatly increased by 
its transmission of mosaic disease from its normal hosts to 
sugar-cane. This phase of its activity has been investigated by 
Dr. Kunkel, and many of the above records of food plants are 
due to his work. Although the corn aphis does not establish 
colonies on sugar-cane in the Hawaiian Islands, immigrants 
undoubtedly settle on the cane plants and are able to live long 
enough to transmit disease. Forced but unsuccessful migrations 
to cane also take place when infested grasses are weeded out in 
the cane fields. 
6. Aphis middletonii Thomas. 
This is a root-inhabiting species on various Compositae and 
has been found in Honolulu on cultivated Coreopsis and China 
aster (Callistephus chinensis (L.) Nees). 
7. Aphis gossypii Glover. 
The cotton aphis, which, according to Van der Goot, is the 
Aphis malvae Walker of European authors, is one of our com- 
monest and most destructive species. Its food plants are very 
numerous, and the list given herewith might be greatly increased 
by careful collecting. Among cultivated plants, it has been 
found in the Islands on cotton (Gossypium barbadense L.), 
Cucumis, taro (Colocasia antiquorum var. esculenta Schott), 
Caladium bicolor Vent., Hibiscus (Hibiscus rosa-sinensis L. and 
hybrids), Clerodendron sp., egg plant (Solanum melongena L.), 
pink and white shower (Cassia nodosa Ham.)., periwinkle 
(Vinca rosea L.), avocado (Persea gratissima Gaertn.), Agera- 
tum (A geratum houstonianum Mill.), hybrid of Plumeria rubra 
L., sunflower (Helianthus annuus L.), marigold (Tagetes erecta 
L.), Mexican creeper (Antigonon leptopus H. and B.), Zinnia 
(Zinnia elegans Jacq.), Lxora (Jxora macrothyrsa Theijsm. and 
Binn.), and hollyhock (Althaea rosea Cav.). 
It also occurs in more or less abundance on the following 
weeds: Bidens pilosa L., Cuphea hyssopifolia H. B. and Kunth., 
Waltheria americana L., Cassia bicapsularis L., Solanum nodi- 
forum Jacq., Malvastrum coromandelinum (L.) Garke, Malva 
parviflora L., Ipomoea pentaphylla Jacq., Desmodium uncinatum 
D C., Crotalaria incana L., Erechtites, Stachytarpheta dichotoma 
