46 
The Colorado Experiment Station. 
proportion of one part to 700 or 800 parts of water; or one of the 
oil emulsions, or miscible oils, in the form of a spray. The appli¬ 
cation is best made early in the morning while the air is quite cool 
and before the insects have become active. If the application is 
made by means of a pump and spray nozzle and with sufficient 
force the thrips can be washed from the onion tops and thoroughly 
drenched, which will destroy a very large proportion of them. 
RADISHES. 
Flea-beetles. 
Little black beetles of more than one species, which jump 
readily when disturbed, often are very severe pests to radishes 
early in the season. Sometimes the first leaves are almost entirely 
eaten as soon as they break through the ground. The injury'is al¬ 
ways done by the adult insects. The characteristic manner of feed¬ 
ing is to eat small holes, hardly larger than a pin hole, through the 
leaves and when these are very abundant, the entire surface of the 
leaf will often die and turn brown. The same flea-beetle also attacks 
tomatoes, potatoes and other garden crops. 
Remedies .—Any fine dust, such as road dust, ashes, slaked 
lime, and land plaster may be freely used upon the plants with 
some good results, but none of these are very effective if the in¬ 
sects are present in large numbers. The arsenical sprays, such as 
Paris green and arsenate of lead will also destroy some of the 
beetles, but are not considered satisfactory. Bordeaux mixture 
such as is commonly used for the control of fungus, diseases, if thor¬ 
oughly applied to the plants, is often very effectual and prevents 
serious injury. I have had the best results, however, from the free 
use of insect powder, or Pyrethrum, applied freely by dusting it 
through a cheese cloth sack very early in the morning. The beetles 
should be brushed from the leaves so that they may be well covered 
with the powder. 
Cut Worms. 
Perhaps the cut worms, of which there are several species in 
Colorado, are the most destructive pests to the average garden. 
These worms burrow just beneath the surface of the ground, where 
they remain in quiet during the daytime, but during the night or 
upon cloudy days it is their habit to come to the surface of the 
ground and feed upon a great variety of plants, having the peculiar 
habit of eating just at the surface of the ground, where they often 
cut the stem of the plants completely off; hence the name, cut¬ 
worm. 
The adult insects are dark-colored moths, expanding about one 
and a half inches when their wings are fully spread. These moths 
