The Locust and Grasshopper 
Problem in Relation to the 
Development of Arid Lands 
B. P. UVAROV 
Anti-Locust Research Centre, London 
Grasshoppers and their larger swarming relations, the locusts, 
are the oldest and most serious enemies of agriculture. Since 
their depredations are particularly great and persistent in the 
regions with arid or semi-arid climate, it should be of interest to 
present a brief outline of the locust and grasshopper problem as it 
already exists in arid lands, and as it may be affected by ac- 
celerated development of them. 
Mosaic Vegetative Cover 
An essential feature of the ecology of grasshoppers is that dif- 
ferent stages of their life are passed in different environments. 
Eggs are laid in the ground, usually in bare spots, whereas the 
young hoppers and adults require abundant vegetation for food 
and shelter. Therefore, a complete environment must include 
two kinds of habitat: oviposition habitat and food-shelter habi- 
tat. This implies that a patchy, mosaic vegetative cover is more 
favorable to these insects than uniform vegetation. 
The mosaic type of vegetation is most typically met with 
where two major vegetation zones are in contact, e.g., forest and 
grassland, prairie and semi-desert, or savanna and desert. It is 
in fact in such transitional belts that grasshoppers and locusts 
generally reach their maximum economic importance. Thus, in 
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