42 
THE COLORADO EXPERIMENT STATION 
upon plants after a rain or while the dew is on and often result in 
the insects disappearing. Particularly is this true in case of flea- 
beetles and the cucumber beetle when feeding upon leaves. Ashes 
do not kill the insects, but they make the food distateful, so the 
insects are driven to other plants. 
31. LIME, PLASTER, AND ROAD DUST. 
These substances are also used like ashes as repellents, but are 
of little or no use for the destruction of insects, except, possibly, 
the pear and cherry tree slugs. 
INSECT TRAPS. 
There are many methods of trapping and destroying insects* 
One of the most common is the use of bright lights exposed at 
night. 
32. LIGHTS. 
The usual plan is to place a light over a dish of some sort that 
contains water with coal oil on top of it. Many night-flying insects 
are attracted by lights and may be destroyed by devices of this kind, 
but there are also many insects that fly at night that are not at¬ 
tracted by lights. Such an insect is the codling moth, though 
light traps are often recommended for its destruction. Among 
those insects that are readily attracted by lights might be men¬ 
tioned the adults of the army worm, of the various cut-worms, the 
garden web-worms, the corn or boll-worm, and the beet-worms. 
It is not infrequently the case that more of the beneficial in¬ 
sects are destroyed than of destructive species, and it is quite doubt¬ 
ful if lights are often of any great importance as a means of lessen¬ 
ing the injury to crops by the destruction of insects. 
33. SWEETENED WATER, CIDER, VINEGAR, ETC. 
Some insects are attracted in considerable numbers to such 
substances as the above, but it is very seldom that the benefit derived 
from them will pay for the trouble and expense of using them. 
Mr. David Brothers, of Edgewater, Colo., reported excellent success 
capturing moths of the fruit-tree leaf-roller with weakened vin¬ 
egar in pans in the orchard, and the codling moth is attracted to 
some extent to a mixture of molasses and vinegar placed in apple 
trees. The advantage of such baits for the capture of insects is 
usually greatly overstimated by those who use them. 
34. BANDAGES. 
Heavy cloth or paper bands placed about the trunks of apple 
trees are quite useful for the capture of the larvae of the codling 
