INJURIOUS INSECTS OF I909Q AND IQIO. 155 
small number remaining will not seriously injure the fruit later. 
Any of the arsenical insecticides can be used. 
CurcuLio: In this state the curculio that works on the apple 
is the plum curculio. The adult curculio hibernates, and on the 
approach of warm weather in the spring is ready to take its first 
meal. At this time they will attack the swelling buds, consequently 
if the buds are covered with an arsenical insecticide many curculios 
will be killed. Later the female curculio lays the egg in the fruit, 
and then makes the familiar crescent-shaped mark. The egg 
hatches into a grub, making the fruit eventually drop. If the 
young fruit can be kept covered with an arsenical spray many less 
eggs will be laid, and many adult female curculios killed at this 
time. 
ScaLe Insects: The principle scale insects found in this state 
are the oyster-shell scale and the scurfy bark louse. The San Jose 
scale is probably present, as it has been found in the states surround- 
ing Minnesota. These are sucking insects, consequently a contact 
or gaseous insecticide must be employed against them. The in- 
sects are covered with a scaly armor that ordinary insecticides will 
not penetrate. Fortunately the discovery of the lime-sulfur wash 
has very nearly solved the difficulty with these pests. The lime- 
sulfur attacks the scaly armor and kills the insect or the eggs 
beneath. The diluted lime-sulfur wash or the self-boiled is excel- 
lent to keep these insects in check during the growing season. 
Scas: This fungus attacks fruit, leaves and young twigs. On 
the fruit small, olive brown patches are first formed. These later 
rupture the skin of the apple and large scabby spots or cracks are 
formed. These permit the entrance of rots later. On the leaves 
and twigs dark patches of velvety texture are formed, sometimes 
with an olivaceous tinge. The disease probably lives over on the 
fallen leaves and, possibly to a certain extent, on twigs and fallen 
fruit. It is liable to be especially prevalent when the weather has 
been damp and cool. 
If the disease has been very bad the previous year, a thorough 
spraying with copper sulfate before the buds swell may be advisable. 
Under ordinary circumstances a spraying with 4-4-50 bordeaux 
