18 BULLETIN 825. U. 5. DEPARTMENT OE AGRICULTURE. 
case of wilt occurred throughout the summer of 1916 in the cucum- 
bers growing in this artificially infected soil in any of the 50 cages, 
although, as in the preceding season, the disease was abundant on 
the plants outside the cages. 
At Giesboro Point. D. C, a second experiment, using 20 similar 
cages, was carried out during 1916 on land planted to Hubbard 
squashes the preceding season. Wilt was very prevalent in these 
vines during the fall of 1915, as verified by personal observations and 
by pure-culture isolations. Many hills bearing wilted vines were 
marked at this time, and 12 of the cages were set directly over such 
hills. A wire netting slightly coarser (16 meshes to the inch) than 
that used in the Long Island experiments was employed for these 
cages, with the result that some of the smaller beetles, especially of 
the second brood, gained entrance. Until the first of July all of the 
cages were gone over every day except Sunday and any beetles or 
gnawed leaves found within were removed. Wilt in this vicinity 
first appeared on June 3 in four near-by fields not in cucurbits the 
preceding season and on June 13 in the cucumbers around the cages. 
On July 5, over a month after the first appearance of wilt in this 
vicinity, a gnawed leaf which had been overlooked in one of the 
cages began to wilt around the points of injury. With the appear- 
ance of many small beetles of the second brood in July it became 
impossible to keep them entirely out of all the cages. On that 
account, after July 25, wilt occurred in single plants in 4 other cages 
out of the 20. In all these cases striped cucumber beetles had gained 
entrance, and the first leaves to wilt were those showing beetle in- 
juries. There was no infection from the soil in any case, but direct 
and positive evidence of infection from cucumber-beetle injuries 
and absence of infection in the absence of such injuries. 
SPRING SEQUENCE OF WILT. 
In addition to the cage experiments during the early part of the 
season of 1916. a complete record was kept of the first appearance 
and spread of bacterial wilt of early cucurbits in all the field and 
garden plats in these two localities. 
At East Marion, Long Island, the area selected comprised the land 
between Long Island Sound and Greenport Harbor and extending 
about 2 miles east and west. (Fig. 1.1 Xo wild cucurbits occurred 
within at least 10 or 15 miles of this locality. 1 
A careful inspection on June 8, 9, and 22 of all cultivated cucurbits vdthin this area 
gave no evidence of ■vrilt. 
The first ^vilt of the season "was found on June 29 on a cucumber plant (fig. 1 in our 
experimental Field IV, planted May 24, 1916, and not in cucurbits the preceding 
season. The plants ^ere just breaking through the ground on June 5, but on account 
i Rand, F. V., and Eniows, Ella M. A., 1916. Op. cit., footnote 2, p. 419. 
