53 
the tar, and thus saves cost and delay. It was tested yesterday by Mr. Raney, of 
Le Sneur County, who is probably the most practical authority in the State, and he 
heartily indorses it, as you will see by his letter. The inventor proposes to rush 
the manufacture of them extensively, and, all things considered, it seems worthy of 
notice. 
We requested Mr. Whitman, our special assistant in Minnesota, to see 
the pan tried; he did so, and found it to work well, though it accom- 
plishes nothing more than the tar pan, and, on account of being more 
expensive at first cost, was not so generally used. The pan has, we 
believe, been patented, and can be built for $6. 
Under the present head may be mentioned the method that has been 
and may be in future adopted, under peculiar and favorable circum- 
stances, of driving the insects into streams and catching them, as they 
float down, in sacks ; and, finally, the use of hand-nets, such as ento- 
mologists ordinarily use in collecting and catching winged insects. This 
method is strongly advocated by Gerstacker, Korte, and other European 
writers, and may be employed with advantage in a small way with us 
where special crops are to be cleared that would be injured by other 
methods. A simple net, such as that herewith illustrated (PI. XII, 
Fig. 4), may be cheaply constructed by any tinsmith ; the only material 
required being a piece of stout wire, a hollow tin tube in which to 
solder the two ends, and a piece of cotton or linen cloth, a wooden 
handle of any desired length being inserted in the non-soldered end of 
the tube. 
(5) Use of Destructive Agents — We had a number of experiments 
made with different insecticide mixtures in 1876 and 1877, and the results 
are given in detail in the first report of the Commission. The only 
substance which indicated possible results of value was Paris green. 
Mixed with twenty to thirty parts of flour it was sprinkled on the ground, 
and many locusts were attracted to and destroyed by it. This mode, 
however, can not be compared with many of those already described. 
Its use against the young locusts is practically of little value, because 
of the excessive numbers in which they usually occur. Broadcast 
spraying of any crop, using, to be effective, Paris green or London 
purple in the proportion of 1 pound to 150 or 200 gallons of water, will 
be useful where spraying apparatus is at hand, but it will hardly pay 
to construct such an apparatus for this purpose alone, in view of the 
cheaper remedies just described. 
the protection of fruit trees. 
The best means of protecting fruit and shade trees deserves separate 
consideration. Where the trunks are smooth and perpendicular they 
may be protected by whitewashing. The lime crumbles under the feet 
of the insects as they attempt to climb, and prevents their getting up. 
By their persistent efforts, however, they gradually wear off the lime and 
reach a higher point each day, so that the whitewashing must be often 
