BIBLIOGRAPHY OF ECONOMIC ENTOMOLOGY. 243 



1736. RILEY, C. V. Continued. 



INTRODUCTORY 1 



Text of circular sent out by the commission, 1 History of the in- 

 vestigation, 1 Need thereof, 2 Early work of Townend Glover, 

 Thomas Affleck, and D. L. Phares, 2 Special report ordered by 

 Congress, 3 Character of the Bulletin, 3 Division of the cot- 

 ton-belt in the southern or hibernating and the northern or 

 non : hibernating portions, 4 Practical aim of the commission, 

 4 Persons who have assisted, 4. 



1. DESTRUCTIVENESS OF THE WORM 7 



Losses occasioned by it 7 



Increase of injury westward, 7 Least injury in northern portion 

 of belt, 7 Tabular statement of loss for past 15 years, 6. 



2. POPULAR AND SCIENTIFIC NAMES FOR THE INSECT 8 



Most desirable popular name, 8 Different technical names by 

 which the insect has been known, 8 Earliest description of 

 it, 8. 



3. CHARACTERS AND STAGES OF THE INSECT 9 



The egg 9 



The worm always hatched from an egg, 9* Where the egg is laid, 



9 Number of eggs to a leaf, 10 All eggs perish during winter, 



10 Other eggs mistaken for those of Aletia, 10. 



The worm or larva 10 



Character of newly-hatched worm, 10 Number of molts, 11 



Variation in color, 11 Peculiar habits, 11 Flourishes on the 



cotton-plant only, 12. 



The chrysalis 12 



Duration of chrysalis state, 13 It never transforms below ground, 



13 How it may be distinguished from other species, 13. 



The moth or imago 13 



Distinguishing characters of the moths, 14 Sexual differences, 



14 Different habits at night and at day, 14 Fecundity, 15 



It finds its natural food on the cotton-plant, 15 Fond of 



fruits, 15 Character of its tongue, 15. 



4. TIME ELAPSING FROM ONE GENERATION TO ANOTHER 16 



It varies greatly, but averages about one month, 16. 



5. TIME OF YEAR WHEN THE FIRST WORMS APPEAR 16 



Prevailing opinions erroneous, 16 The worms hatch in April, 

 16 First worms always in small numbers, 17 The third gen- 

 eration usually called the first, 17. 



6. CONDITION OF SOIL AND PLANT CONNECTED WITH THE APPEARANCE 



OF THE FIRST WORMS i 18 



The worms appear first on low, moist, and rich lands, 18 Few 

 exceptions to the rule, 18 The plant must be well advanced 

 and luxuriant, 18 Some shelter generally near, 19 Reoccur- 

 rence year after year in the same spots, 19 Theory explaining 

 first appearance under the circumstances observed, 19. 



7. WET WEATHER FAVORS THE DEVELOPMENT OF THE WORMS 20 



Humid and hot atmosphere most favorable, 20 Heavy storms 

 , destroy, 20 Effect of dryness, 21 Indirect influences of wet 



weather, 21 It prevents the working of the worm's natural 

 enemies, 21. 



