B. P. I.— 318. 



THE MULBERRY AND OTHER SILKWORM 

 FOOD PLANTS. 



INTRODUCTION. 



The small group of trees belonging to the family Moracese includes 

 those which supply the silkworm with food. There are three genera 

 in the group: Moras, the mulberry (Pis. I to VI); Toxylon, the 

 Osage orange (PI. VII, fig. 1), and Broussonetia, the paper mulberry 

 (PL VII, fig. 2). The last named is not true mulberry, although 

 often mistaken for such and in some States miscalled the " white 

 mulberry " on account of the white under surface of the leaf. It is 

 absolutely worthless as a silkworm food plant. 



The Osage orange provides excellent silkworm food only when ma- 

 tured leaves are used. Young succulent leaves when fed to the Avorms 

 cause disease. Silk from the Osage leaves is of a very fine quality, 

 but the young branches of this tree are thorny; this, together with 

 the manner in which the leaves wither and pack down after gather- 

 ing, makes them inferior to those of the mulberry. The young mul- 

 berry buds can be fed to the worms in the spring at a time when the 

 Osage orange buds have not even commenced to swell. 



The mulberries proper consist of several species, and of these there 

 are numerous varieties. The white mulberry (Jlorus alba), shown in 

 Plates I, II, and III, is most prized for feeding the silkworm; it is 

 too tender, however, in northern latitudes with severe winters. The 

 Russian mulberry (PL IV), which is a variety of the white mulberry 

 (J/, alba var. tatarica), is better adapted to cold regions. Although 

 the leaves are smaller than in those of the white mulberry and much 

 divided, entailing more work in feeding the worms, it is, nevertheless, 

 considered an excellent food for silkworms. The Chinese multicaidis, 

 another variety of the white mulberry, much favored for feeding pur- 

 poses, is too tender in northern latitudes. Other varieties of Jlorus 

 alba more or less used are Moretti. Downing, Rosea, and Japonica. 

 The venosa variety of the white mulberry (PL VI) is used only as an 

 ornamental plant and has no value for feeding silkworms. 



The other two species commonly grown in the United States are the 

 black and the red mulberry. The black (Jlorus nigra) is sometimes 



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