378 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



REPORT OF C. V. RILEY, STATE ENTOMOLOGIST OF MISSOURI, 



FOR 1871. 



Mr. Charles V. Riley, Stale Entomologist of Missouri, vin- 

 dicates his right to the office by the timely publication of an 

 annual report for 1871 (the fourth of the series) upon the nox- 

 ious, beneficial, and other insects of the State of Missouri. 

 The report, which occupies 150 pages, is filled with valuable 

 memoirs upon various species of insects, in which the pecul- 

 iarities of the past season are indicated in the exceptional 

 abundance or rarity of certain well-known forms, and in the 

 appearance of species that had not been previously detected. 

 An article on the grape-vine louse, which had already ap- 

 peared in the Rural New Yorker, is reproduced with additions, 

 and constitutes a valuable contribution to the history of this 

 destructive pest. His practical suggestions as to remedies 

 will be well considered by horticulturists. 



As might be expected, the Colorado potato beetle, which 

 has already done so much mischief, receives prominent atten- 

 tion, and the new territory invaded by it during the year is 

 recorded, and points are indicated as likely to fall within its 

 march during the present season. A considerable portion of 

 the report is occupied by a paper upon silk-worms, of which 

 the different species are mentioned, and their special applica- 

 bilities under different circumstances. 



HATCHING SILK-WORM EGGS AT WILL. 



M. Duclaux has presented to the Academy of Sciences of 

 Paris an article upon the method of producing at will the 

 hatching of the eggs of the silk-worm, in which he remarks 

 that shortly after their discharge, and as soon as a change of 

 color takes place, the egg enters upon a kind of rest, or sleep, 

 which usually lasts until winter, and from which it can only 

 emerge under the action of cold, in consequence of which the 

 evolution of the embryo stationary until that time has a 

 beginning. The impulse once given, this evolution must go 

 on, and sometimes is interfered with very materially by con- 

 tinued cold, so as to cause the death of the eggs, or else re- 

 sults in a feeble progeny, that becomes involved in disease. 

 The duration of this second period in the history of the egg, 

 occupying from 3 to 3- 1 months, can not be materially modi- 



