BIBLIOGRAPHY OF ECONOMIC ENTOMOLOGY. 
293 
2] 19. Riley, C. V.—Continued. 
Silk culture—C ontinued. 
United States, 9—Various reports from correspondents of the 
division, 9—Experience in 1882 at the Department in raising 
worms fed on osage orange or mulberry, 11—New mulberry tree 
from southern Russia, 13—Business ventures in the United States 
in connection with silk-producing industry, 13—Sale of eggs, 13— 
Second edition of the manual of silk culture, 14—Preface thereof, 
14—Reasons why the growing interest in silk culture in the 
United States should be checked at the present time, 15—Import 
duty on raw silk demanded, 16. 
Pyrethrum: Its use as an insecticide. 16 
Circular in reference to Pyrethrum, 16—Distribution of seed by the 
Department, 16—History of Pyrethrum in Asia and Dalmatia, 
17 — Experience in growing Pyrethrum roseum in America, 17 — 
Soil best adapted for raising the plant, 18—The Dalmatian plant 
in California, 18—Experience with raising the plant at Washing¬ 
ton, 18—Preparation of the plant for use, 18—Gathering and dry¬ 
ing the flowers, 18—Pulverizing, 19—Keeping the powder, 19— 
Advantages and disadvantages of the powder as an insecticide, 
19—How Pyrethrum affects different insects, 19—Modes of ap¬ 
plication, 19—Pyrethrum as dry powder, 19—Pyrethrum applied 
in fumes, 20—Alcoholic extract, 20—The powder stirred up in 
water, 20—Tea or decoction, 21—Reports from persons to whom 
Pyrethrum seed was sent, 21—Success in raising the plant at 
Washington, 24—Miss M. E. Murtfeldt’s experiments with pow¬ 
der on various insects, 25. 
Chinch-bug notes, Blissus leucopterus . 27 
Professor Thomas’ predictions for 1881, 27—1881 a chinch-bug year, 
27—Injury in spring of 1882 in the western States, 27—Irriga¬ 
tion as remedy, 28—Use of kerosene emulsions, 29. 
The army worm, Leucania unipuncta .- 29 
Habits and natural history, 30—History of investigation in America, 
30—Where the eggs are laid, 30—When the eggs are laid, 31— 
Mode of oviposition, 31—Prolificacy of the moth, 32—Duration 
of the egg state, 32—Habits of the young worms, 32—Guen^e’s 
characterization of Leucania larvte, 32—Marching of the worms 
abnormal, 33—The marching worm not a distinct race, 33—Dura¬ 
tion of worm life, 34—Remedies, 34—Burning old grass, 34— 
Predictions of army-worm years unreliable, 35—Meteorological 
influences on the species, 35—Ditching and fencing as remedies, 
36—Use of arsenical poisons, 36—Kerosene and coal tar, 36— 
Heavy rolling not to be recommended, 37—“ Drawing the rope” 
of little avail against the worm, 37—Mr. L. O. Howard’s report 
on army-worm injury, 1881, in Illinois and Indiana, 37—Reports 
from correspondents, spring of 1882, 39—Rev. Samuel Lock¬ 
wood’s account of the invasion of 1880, in New Jersey, 44. 
Scale insects of the orange, by H. G. Hubbard. 46 
Characterization of the species, 46—Comparative destructiveness 
of the three species treated of, 47—Periods of migration, growth, 
and incubation, 47—Scale insects easily assailable only during a 
brief period of their development, 48—The hatching process and 
its maximum periods, 48—Great vitality of the eggs, 49—The 
work of enemies and parasites, 49—Lady-bugs, lace-wings, and 
lepidopterous enemies, 48 — Importance of mites as external 
