INSECT NOTES FOR IQ2I-22 5 
other insects. The so-called “bran bugs” which are often present in 
the state in small numbers were particularly abundant in 1921. 
This unusual situation became more complex because recent rul- 
ings by insurance underwriters, railroads, and others have prohibited 
the use of carbon disulphide. Carbon disulphide has been universally 
recommended by entomologists for fumigating infested grain. Much 
time has been devoted to the study of fumigants in an effort to provide 
the grain growers and dealers with some adequate means of protecting 
their grain from these pests. 
In 1922 the superabundance of these granary pests decreased, but 
the experimental work on fumigants is siill being carried on vigorously 
under the direction of Dr. R. N. Chapman. Preliminary work indicates 
that in normal years elevators and granaries can be kept free from 
granary weevils and bran bugs by so handling the grain that the tem- 
perature is kept at or below the freezing point. If the grower would 
grade and clean his grain during the first cold snap of the fall it 
would seem that he would have very little trouble from these pests. 
Potato Leaf Hopper (Empoasca mali Le B.) 
- Probably the insect about which the most complaints were made 
in 1921 was the potato leaf hopper. It has been in the state for many 
years, but it is only in particularly dry seasons that it seems to do 
serious damage in Minnesota. In 1916 a very bad outbreak 6ccurred, 
but at that time the seriousness of the pest was not thoroly realized 
and its connection with “hopper burn” not fully recognized. ° S. Marco- 
vitch, working with this insect here at that time, was convinced of 
its seriousness and its relation to hopper burn, and published his con- 
clusions in the local press. Between 1916 and 1921 there were no 
serious outbreaks in this state, but in 1921, taking the state as a whole, 
this leaf hopper was responsible for a 25 per cent damage. In 1 
this damage was equally severe. 
In our experimental plots where different liquids and dusts were 
tried, liquid bordeaux mixture (4-4-50) applied at 175 pounds pressure, 
three nozzles to the row, and applied three times during the season 
gave good control. No other spraying compound was nearly as effec- 
tive. This again bears out our recommendations of several years ago, 
advocating high pressure and better sprayers. 
Grasshoppers 
In 1921, Minnesota was threatened with a grasshopper outbreak. 
Fortunately a wet June in the infested areas caused the death of most 
of the young hoppers. In Kittson County one large area was infested 
