BIBLIOGRAPHY OF ECONOMIC ENTOMOLOGY. 317 



2267. [RiLEY, C. V., et al.] Continued. 



CHAPTER III Continued. 



ones, 23 Characteristics of thepermanent region, 24 Settlement 

 and other checks against locusts, 25 Distribution of the perma- 

 nent regions, 25 Their physical peculiarities, 28 The arid re- 

 gion, 29 Permanent breeding grounds, 29 Their locations and 

 relations, 30 The sources of locusts, 30 Interchange of swarms, 

 31 Regular migratory routes, 31 Agencies controlling migra- 

 tion, 32 Disadvantages of the temporary regions, 33 Period of 

 hatching, 34 Period of growth, 35Habits of the young, 36 

 Habits at maturity, 36 Causes of occasional over-increase, 37 

 Checks, enemies, 38 The efforts of experts baffled, 42 Tree 

 culture, 42 Climatic checks, 43 Tree planting, 43 Flights 

 affected by storms, 45 Number of annual broods, 46 Sub-per- 

 manent region, 46 Its relations, 47 Locust movements therein, 

 48 How to fight this insect, 49 Locust probabilities, 49 Re- 

 cent swarms, 50. 



CHAPTER IV: 

 Notes on other locusts and on the Western cricket, Anabrus. By 



Lawrence Bruner 1 '. 53 



Other locusts, 53 List of North American locusts north of Mexico, ' 

 55 The Western cricket, 61. 



CHAPTER V: 



Data obtained from solar physics and earthquake commotions ap- 

 plied to elucidate locust multiplication and migration, by A. H. 



Swinton 65 



Importance of the central luminary, wide effects of variation in its 

 potential energy, 65 On the tides, on chemical and organic ac- 

 tivities, on the physical forces, on epidemics, etc. ,65, 66 Periods 

 of sun-spots, electrical effects of, 66 Thermometric effects of, 

 67 Volcanic effects of, 68 Entomological effects of, 68 A new 

 snn-spot table, 69 Statement and tabulation of sun-spot dates, 

 69 Comparison of sun-spot periods and insect periods, 73 

 American locusts diminished by the spots, 73 European confirm- 

 ative examples of locusts and other insects, 74 Tabulation of 

 rare insect captures, 79 Explained, 81 Migration and distribu- 

 tion affected, 81 Locusts again predicted in four or ten years, 

 83 Conclusions, 84. 



PART II. THE ARMY-WORM, CANKER-WORMS, AND THE HESSIAN FLY. 



CHAPTER VI : By C. V. Riley. 

 The army-worm, Leucania unipuncta. By C. V. Riley 89 



Nomenclature, 89 Other army-worms, falsely so called, 89 Geo- 

 graphical distribution, 91 Injuries by, 92 Past history of, 92 

 Descriptive characters of, 101 The egg, 101 The larva, 102 

 The pupa, 103 Adults and sexual differences, 103 Habits and 

 natural history, 105 Oviposition, 105 Habits when young, 108 

 Duration of larval life, 109 Traveling habits, etc., 110 Time of 

 appearance, 112 Sudden appearance and disappearance, 114 

 Food-plants, 116 The pupa state, 117 Habits of the moth, 117 

 Flight, 118 Position at rest, 118 Number of broods yearly, 118 

 Hibernation, 122 Natural enemies, 125 Remedies, 128 Burning 

 old grass, etc., 128 Predictions, meteorological influences on the 

 species, 129 Ditching, coal-tar, poisoning, 130 Rolling, fencing, 

 roping, 131 Report of observations by L. O. Howard, 132 Ex- 



