STUDIES OF INSECT TRANSMISSION AND CROSS- 
INOCULATION OF MOSAIC ON THE SOLANACEAE, 
CUCURBITACEAE AND LEGUMINOSAE 
O. H. ELMER 
The results of most investigators tend to show that the mosaic 
disease is quite limited in its host range. Recent experiments 
show that such is probably not the case. 
Four petunia plants were inoculated with mosaic from squash 
and four egg plants with sweet potato' mosaic. All became in- 
fected, while the checks remained healthy. An experiment in 
which juice of a mosaic plant was inoculated under long continued 
pressure through a capillary tube resulted in 100 per cent infection. 
Using this method, eight squash plants were inoculated with the 
mosaic from tobacco and tomato. At the same time a tobacco 
and a tomato plant were inoculated with mosaic from squash and 
became infected. An equal number of checks were held and all 
remained healthy. In addition, two tomato plants inoculated with 
mosaic from squash by means of a hypodermic needle became 
infected. Five tobacco plants inoculated with crookneck squash 
mosaic with a flamed knife became infected within twelve days. 
The thirty checks remained healthy. 
Cow pea plants ( Vigna Catjang) growing in the Agronomy 
greenhouse were found severely infected with mosaic. Inocula- 
tion by means of aphis (species undetermined) from the mosaic 
plants to healthy plants has shown beyond doubt that this mosaic 
is a transmissible disease. Two pots containing thirty-eight cow 
pea seedlings were infected with asphis from the mosaic cow pea 
plants and were placed in insect proof cages. Both pots were 
ringed with tree tanglefoot to keep other insects away. One hun- 
dred per cent infection occurred in both pots, while all checks 
remained healthy. Artificial inoculation has, to date, proved un- 
successful. 
It is known that aphis are capable of transmitting mosaic. As 
far as I know, the mealy bug ( Dactylopus ) has not been reported 
as transmitting this disease. However, evidence has been obtained 
which indicates that this is the case. An experiment in which 
