LOCUST PLAGUE—UVAROV 335 
danger. In northern Borneo, locusts can breed only in areas where 
the jungle has been cleared for cultivation and abandoned after a few 
seasons; such shifting cultivation there, and probably in other similar 
areas, is a direct cause of locust outbreaks. In western Australia, 
the clearing of dry forests in the interests of sheep breeding has created 
a type of grassland admirably suited for locusts. Overgrazing of 
natural pastures is largely the cause of the great, and growing, grass- 
hopper menace in Argentina, some parts of the United States, Canada, 
and parts of Russia. Such facts led the Fourth International Locust 
Conference, held in 1936 at Cairo, to pass a resolution pointing out that 
the mass development of locusts and grasshoppers is furthered rather 
than hindered by man’s activities, and that no hopes can be entertained 
of the problem’s becoming less acute merely as a result of the general 
development of a country. 
To this must be added the consideration that the agricultural de- 
velopment of new areas, e. g., in Africa, central Asia, etc., tends to 
increase the danger from locusts in direct proportion to the increase 
in the value of crops exposed to their ravages. 
THE USES OF LOCUSTS 
It may well be asked whether it might not be possible to find some use 
for the mass of organic matter represented in locust swarms, some of 
which have been estimated to amount to hundreds of tons. Chemical 
analyses show that locusts contain protein, fats, and mineral salts, 
which would be of value in the preparation of fertilizers and of food 
for cattle and poultry. From the technical point of view the idea is 
sound, but no industry can be based on a raw material which may be 
overabundant one year and nonexistent the next. 
The use of locusts for food is well known, since John the Baptist 
lived on them, as Bedouins in Arabia still continue to do when other 
food is scarce. The Assyrians apparently considered locusts as food fit 
for kings, since a bas relief of the seventh century B. C. shows locusts 
being brought up to the table of Asshurbanipal. Locusts are still 
eaten in many countries, and the Philippine Department of Agricul- 
ture has recently published a pamphlet describing 33 different ways 
of cooking them. Some of the recipes sound rather attractive in war- 
time, perhaps, because they include such ingredients as eggs, bananas, 
lemons, and pineapples. More plainly cooked locusts were recently 
described by an entomologist as “neither repulsive nor producing any 
pleasant sensation.” 
LOCUSTS AND THEIR HABITS 
We have been speaking of locusts as a plague of agriculture, but in 
order to understand the problem, it is necessary to have a clear idea 
