162 INJURIOUS INSECTS OF IQ0Q AND IQIO. 
Flowers are produced, but few fruits are matured, and those which 
come to maturity are usually small and misshapen. 
Spraying to control the pest should begin as soon as the vines 
begin to run, and should be continued every ten days or two weeks. 
4-4-50 bordeaux may be used, although it is often recommended 
that the first spraying be made with 3-6-50 and the subsequent ones 
with a 4-4-50 mixture. 
PowveEery MiLpEw: This produces the powdery patches char- 
acteristic of powdery mildews. Usually it is not very destructive 
and will yield to the treatment applied to control downy mildew. 
SCLEROTINIOSE OR SCLEROTIUM DisEASE: In the greenhouse 
this disease may do considerable damage, although out of doors it 
occurs but rarely. The stems become soft and yellowish, finally 
drying up. A white, fuzzy mass may also appear. Slender black 
storage organs may appear. Affected vines should always be re- 
moved before these storage organs appear and the place from which 
they were removed should be very thoroughly sprayed with bor- 
deaux or some other fungicide. 
Witt: This disease is of bacterial origin. It has not been 
found on cucumbers in Minnesota, but was found on squash in 
I910, so a description will be given, since it is probably present. 
It causes the vines to droop and, finally to die. It is spread mainly 
by biting insects, and, possibly to some extent, lives over in the soil. 
Spraying to prevent other fungous diseases and insects will aid in 
preventing the spread of the wilt. Rotation of crops may also prove 
beneficial. Destruction of diseased vines is, of course, necessary. 
TUBERCULAR OR Wart DISEASE: The cucumbers are covered 
with knob-like protuberances which later may cause the entire fruit 
to become misshapen. Although considerable work nas been done: 
at this Station in attempting to control the trouble, no effective 
remedy has yet been found. 
Currant. 
The currant worm, the larva of a saw fly, is the worst insect 
pest of this shrub. As the insect eats the leaves, however, it is 
easily combated with a stomach insecticide. 
Currant Apuis: ‘This plant louse works on the under side of 
the leaves causing reddish, swollen discolorations. They are quite 
hard to combat, living as they do, entirely on the under side of the 
