48 
insect enemies, which kill them off in ordinary seasons. With 
changes of atmospheric conditions, however, the insect and fungous 
enemies are frequently destro^^ed, and then the grasshoppers increase 
in abundance. In such cases they can be destroyed b}^ several artifi- 
cial methods. The remedies that have proved most efficient are: 
(1) plowing under the eggs before these have had time to hatch, and 
Fig. 48.— a simple coal-tar pan to be drawn by hand (after Riley). 
(2) capturing the unfledged locusts, as well as many of those which 
have become winged, by means of hopperdozers or kerosene pans. 
Hoppei'dozers are necessary implements of warfare against most 
grasshoppers. They are shallow sheet- iron pans, made of an}^ size 
most convenient, or canvas frames, mounted on runners to be drawn 
over the ground either by a horse or by hand, preferably against the 
wind, in such a man- 
ner that the grass- 
hoppers will leap into 
them and be killed by 
coming into contact 
with the tar or oil 
which is poured into 
them for the purpose. 
Two forms of hop- 
perdozers are shown 
in figures 48 and 49. 
Bran-arsenic mix- 
ture is another rem- 
ed}^ of great value in 
the prevention of injur}^ to our cultivated crops. The directions for 
preparing this mash have been given under remedies for cutworms 
(page 185). 
Fungous diseases as a remedy. — During the ^^ears 1901-2 the subject 
of the possible control of grasshoppers by means of contagious diseases 
was taken up by the Division of Entomology, and a report by Dr, 
Flu. 4y.— A canvas liopperdozer to be drawn by liorse (after Riley). 
