22 
Colorado Experiment Station 
If treCvS are found to be infested, immediate action should be taken. 
jSmall trees may be killed in one or two seasons and older treesi so 
weakened that they are of little value. This scale has been discovered 
in one fruit growing section of Colorado, and may break out in others 
at any time. Anyone finding scale insects that he can not identify 
should send them to the Experiment Station for identification. 
Remedies .—Spray with lime and sulphur mixture (16-17) while 
trees are dormant. The soluble or miscible oils (12) are also quite 
effective. It is usually best to cut and burn badly infested trees. 
Putnam Scale —This very closely resembles the preceding species. 
Mature scales are slightly larger and lighter in color and the central 
spot on the scale is reddish and somewhat to one side of the center. 
Remedies the same as for the preceding. 
Howard Scale .—This scale is very difficult to distinguish, in ex¬ 
ternal appearance, from the preceding species. It is about the same 
size and has a pale gray color, with a dark orange colored nipple some¬ 
what to one side of the center. 
This species is pretty generally scattered over the State. It doe^; 
most damage to the pear, plum and prune, but also infests apple, peach, 
ash and maple. Tt canses a peculiar pitting of the surffirp of pears. It 
Fig. 11.—Oyster-shell Bark-louse: a, female scale from below, showing eggs, greatly 
enlarged; b, the same from above; c, female scale on twig, natural size; d, male scale en¬ 
larged Howard, Yearbook, U. S. Dep. of Agr., 1894. 
