270 BIBLIOGRAPHY OF ECONOMIC ENTOMOLOGY. 
1959. [Riley, C. V.]—Continued. 
Chapter III: By C. Thomas. 
Facts concerning and laws governing the migrations of locusts in all 
countries.•-. 31 
Most species of Acrididce not migratory, 31—Migratory disposition 
not caused by anatomical differences, 31-32—Writers on locust 
flights, 32-33—Earliest accounts of locust flights in Europe, 33- 
34—Locust flights in Europe in the middle ages, 34-37; in the 
seventeenth century, 37-38—The locust invasion of 1693 in Eu¬ 
rope, 38-39—Locust flights in Europe in the eighteenth and 
nineteenth centuries, 40-41—Locusts in Asia and adjacent 
islands, 41; in Cyprus, 42; in Arabia and Syria, 43-44; in Per¬ 
sia, 44; in the Steppes, 45; in China, 46; in Manila, 46; in 
India, 46-47 ; in Australia, 47; in New Zealand, 47—Locust 
flights in Africa, 48; in northern Africa, 48-49; in Egypt, 49— 
in Algiers, 50-51; in Abyssinia, 51; in central Africa, 51; in 
eastern Africa and the Canary Islands, 52-53—Locusts in South 
America, 53-54—Prevalence of locusts in deserts and dry regions, 
54-55—Locust flights not governed by laws of periodicity, 55- 
56—Permanent breeding grounds of locusts, 56-57—Their geo¬ 
graphical distribution, 58— Caloptenus spretus not in Mexico, 58— 
Migratory locusts in Yucatan and the West Indies, 58-59—In 
Nicaragua, 59—Geographical limits of Caloptenus spretus, 59; of 
Pacliytylus migratorius, 59-60—Difficulty of determining species, 
60-61—Definition of permanent home of migratory locusts, 62— 
Range of Pacliytylus migratorius, 62-63 ; of Acridium peregrinum, 
63-64—Comparison with the laws of geographical zoology, 65- 
66—Meeting point of three sub-regions, 67—Each species has its 
permanent breeding ground, 68—General character of the per¬ 
manent breeding grounds, 68-69—Breeding ground of Caloptenus 
italicus,69j of Pacliytylus migratorius , 69-70; of Acridium pere¬ 
grinum, 70; of Caloptenus spretus, 70-71. 
Chapter IV: By C. Thomas. 
Habits and characteristics of locusts in all countries within their 
areas of permanent distribution, so far as these relate to their 
movements... 72 
Caloptenus spretus always migratory, 72-73—Flights of C. spretus, 
73-74—Invading swarms come from northwest, 74-75—Other 
opinions eliminated, 75-76—Swarms in 1875 and 1876, 7fl-77—Di¬ 
rection of returning swarms of C. spretus, 78; of other migratory 
locusts, 78-79—Direction of local flights, 79-81—Returning 
swarms do little injury, 81-82—Distance to which swaruis may 
migrate, 82-84—Length of a single flight, 84-85—Swarms able to 
cross large bodies of water, 85-86—Swarms carried far by winds, 
86-87—The mode of flight, 87—Position of the locust while fly¬ 
ing, 87-88—Locusts flying with the wind, 88-89—Method of fall¬ 
ing of swarms, 89—Formation of swarms, 89-91—Movements of 
swarms of C. spretus, as reported by Dr. Child, 91-93—Other re¬ 
ports, 94—Movements of swarms in other countries, 95-96— 
Swarms usually alight at night, 96-97—The height at which 
swarms move, 98-100—Different directions of swarms at the same 
time and place, 100—Fall of locusts into the sea, 100-102—Great 
flyiug power of locusts, 102—Geueral causes of migration, 103— 
Excessive numbers, 103-104—Want of food, 104—Excessive heat, 
