43 
machine is so simple in construction that any ordinary workman can put them up at 
a comparatively small price. The machine may he made of any size desired, from a 
small hand-machine to one a rod or more in width. 
PI. ix, Fig. 2, represents a front view of this machine when in oper- 
ation, and Fig. 3 a side view of the frame. 
(3) Trapping. — This can be easily accomplished, especially when the 
locusts are making their way from roads and hedges. The use of nets 
or seines, or long strips of muslin, calico, or similar materials, converg- 
ing after the manner of quail nets, has proved very satisfactory. By 
digging pits or holes 3 or 4 feet deep, and then staking the two wings so 
that they converge toward them, large numbers may be secured in 
this way after the dew is off the ground, or they may be headed off 
when marching in a given direction. Much good can be accomplished 
by changing the position of the trap while the locusts are yet small and 
congregate in isolated or particular patches. 
Ditching and trenching properly come under this head j and both plans 
are very effectual in protecting crops agaiust the inroads of traveling 
schools of the insects. They were found especially advantageous in 
much of the ravaged country in 1875, where there was little or no hay 
or straw to burn. They are the best available means when the crops 
are advanced, and when most of the other destructive methods so ad- 
visable early in the season can no longer be effectually used. Simple 
ditches, 2 feet wide and 2 feet deep, with perpendicular sides, offer 
effectual barriers to the young insects. They must, however, be kept in 
order, so that the sides next the fields to be protected are not allowed 
to wash out or become too hard. They may be kept friable by a brush 
or rake. 
The young locusts tumble into such a ditch and accumulate and die 
at the bottom in large quantities. In a few days the stench becomes 
great, and necessitates the covering up of the mass. In order to keep 
the main ditch open, therefore, it is best to dig pits or deeper side ditches 
at short intervals, in which the locusts will accumulate and may be 
buried. If a trench is made around a field about hatching-time, but 
few locusts will get into that field until they acquire wings, and by that 
time the principal danger is over, and the insects are fast disappearing. 
If any should hatch within the inclosure, they are easily driven into the 
ditches dug in different parts of the field. The direction of the appre- 
hended approach of the insects being known from their hatching local- 
ity, ditching one or two sides next to such locality is generally suffi- 
cient, and when farmers join they can construct a long ditch which will 
protect many farms. 
Where the soil is tenacious and water can be let into the ditches so 
as to cover the bottom, they may be made shallower and still be effec- 
tual. The width and depth of the ditch is important, and as experience 
differed somewhat, I have been at pains to get the experience of a large 
number, of correspondents addressed by circular. Many have success- 
