12 BULLETIN 131, tJ. S. DEPARTMENT OF AGRICULTURE. 



It is stated that the method was in use throughout Brazil and that 

 unusually good results had been obtained. 



During the same year (1910) Mr. A. C. Morgan, of the Bureau of 

 Entomology, in an article on insect enemies of tobacco in the United 

 States (70), briefly described methods of treatment with fumigants. 

 It was stated that no method entirely satisfactory had been found 

 for the treatment of baled tobacco. The results of experiments with 

 Rontgen or X rays in the treatment of infested tobacco, conducted 

 by Mr. A. C. Morgan and the writer, were published in 1913 (76). 



From Manila, P. I., in 1913, Mr. Charles E. Jones (77) published 

 the most comprehensive article on the tobacco beetle which had yet 

 appeared. The life history and seasonal history of the insect in the 

 Philippines were determined and many practical methods of control 

 tested under cigar-factory conditions. An exhaustive series of tests 

 with hydrocyanic-acid gas showed this fumigant to be effective in 

 treating infested cigars without affecting their quality. 



Storage of infested tobacco at low temperatures is recommended 

 by Mr. D. T. Fullaway (79) in a publication of the Hawaii Agri- 

 cultural Experiment Station in 1914. In 1916 the results of experi- 

 ments with Rontgen or X rays on different stages of the beetle were 

 published by the writer (86). In 1917 the writer (89) published a 

 general account of the species, its life and habits, and methods of 

 control. 



In the historical sketch given only the more important publica- 

 tions relating to the life history of the insect or to the measures em- 

 ployed in its control have been cited. In the bibliography (p. 69-77) 

 reference will be found to most of the papers, relating to the insect, 

 which have been published in permanent form. A synopsis is given 

 of the contents of the more important publications. 



DESCRIPTION OF STAGES. 



THE EGG. 



(PI. I, fig. 8.) 



Egg about 0.45 mm. (0.44-0.46 mm.) long and 0.2 (0.19-0.21 mm.) in diameter; 



ovoid elliptical, pearly white, becoming more opaque and dull in color just before 



hatching. Surface smooth, without reticulation or sculpture except a portion at 



the end from which the larva emerges, which is covered with numerous papillae. 



THE LARVA. 1 



(PI. I, figs. 1-7.) 2 



GENERAL CHARACTERS. 



Ventral side of epicranium not continued behind the posterior end of hypos- 

 toma and its tentorial pits; gula transverse, laterally attached to the posterior 



1 In order that the identification in the field may he as accurate as possible it is neces- 

 sary from time to time to incorporate in an economic bulletin technical descriptions. 

 These descriptions are drawn* up after extremely careful study of the anatomy of the 

 larva by a specialist on the group. The following descriptions, kindly prepared by Dr. 

 Adam Gr. Boving, will be of great assistance in future studies of ptinid larvae. First is 

 presented a description of the characters common to many ptinid larvae, then the charac- 

 teristics of the genus, and finally the specific characters of Lasioderma serricome. 

 Description of larva (with PI. I, figs. 2-7) made by Dr. Adam O. Roving. 



