202 



THE AGRlcaLTUKAL NEWS. 



June 22, 1912. 



INSECT NOTES, 



THE YELLOW FEVER MOSQUir'>. 



At the first International Congress of Entomology at 

 Brussels, in August 1910, Mr. Fred. V. Theobald, M.A., 

 F.E.S., presented a paper entitled The Distribution of the 

 Yellow Fever Mosquito {Steyomi/ia Jasciatus, Fabr.) and 

 General Notes on its Bionomics, which has appeared in the 

 volume of the Memoirs of the Congress (p. 145). 



The following notes are abstracted from Mr. Theobald's 

 paper. 



The yellow fever mosquito occurs throughout the tropi- 

 cal and sub tropical regions of the world, as the common 

 domestic day-iiying mosquito. It never appears to occur far 

 from the habitations of men, and though its attacks are 

 usually most noticeable during the day, it also bites at night, 

 at leasi in certain localities, notably the West Indies. 



Yellow fever occurs as an endemic disease only in the 

 American hemisphere and on the West Coast of Africa. 

 There is a liklihood, however, that with the opening of the 

 Panama Canal, infested mosquitoes will be transported to 

 many of those locations where the Stegomyia mosquito 

 occurs, which have up to the present time been free from 

 yellow fever, with the result that the disease may become 

 world-wide in its distribution. 



The possibilities of such transportation would seem to 

 be great, since an adult Stegomyia mosquito is capable of 

 remaining alive for forty-seven to fifty days, which is a period 

 more than will be necessary for steamships to travel to all 

 parts of the Pacific and Indian Oceans from the endemic 

 yellow fever countries in the West Indies and Central 

 America 



SILK PISH LINES. 



The Journal of the Colleijc of Agriculture of the 

 Imperial University of Tokio, Vol II, No. 2, contains an 

 article by Professor C Sasaki on The Silk Fish Line The 

 method of obtaining and preparing silk fi.sh lines is briefly 

 noted here as likely to be of interest to readers of the Agri- 

 cultural News. 



It would appear that the use of these lines dates back 

 to very remote times, especially in Japan; but the Japanese 

 have had but fragmentary knowledge of the source from which 

 they are obtained and the manner of their preparation. 



Professor Sasaki reviews at some length the historical 

 records of the sources of the silk fish lines. He finds that 

 they are procured from wild silk worms. 



Recently, specimens of the moth have been identified by 

 Sir George Hampson as Saturnia pi/ritoru/H, Westwood. 

 The larvae feed upon the leaves of Camphor and Liquidamhur 

 formosana, and are most abundant in cprtain districts of 

 South China, where most of the .silk fish lines are produced. 



When the larvae are fully developed, many of them 

 descend to the trunks and lower branches for the purpose of 

 pupating These are collected, while the most of those 

 which remain in the higher branches of the trees are allowed 

 to pupate and emerge as moths, thus providing for the next 

 generation of larvae; a few are gathered by means of a funnel 



on a bamboo. The caterpillars which have been collected 

 are put into a large earthen bowl (I feet high and about 2 feet 

 in diameter) until it is about one-half full, and the bowl is 

 then filled with water. At the end of from twelve to twenty- 

 four hours, all, or very nearly all, the worms are dead. The 

 caterpillars are taken from the water, a slit is made in the 

 ventral surface of each one, and the two long silk glands are 

 drawn out of the body. These silk glands are then soaked 

 for a time in strong vinegar; after this they are transferred 

 to water and thoroughly washed and rubbed between the 

 fingers. About sixty of these glands are then fastened by 

 one end to a bamboo stick which is then thrust into the mud 

 wall of the house. Each of the glands is then drawn out 

 until it is stretched to its full extent, and fastened to another 

 stick thrust into the mud wall. In this way the silk glands 

 are kept stretched between two supports until they are 

 thoroughly dried in the air, and become firm and strong. 



When they are sufficiently dried, the filaments are fur- 

 ther washed, and dried again, and then made up into bundles 

 of fifty or sixty filaments; each of these bundles is formed 

 into a ring 8 or 9 inches in diameter, in which condition 

 they are ready for rcarket. 



THE RATTANS OR ROTANGS. 



The 'rattan canes' of commerce are the stems of two Old 

 World genera of palms — Calamus and Daemonorops — of 

 which, jointly, about 300 species are known. With few 

 exceptions, they are climbers from tree to tree, in dense 

 forests. The distinguished traveller and botanist, Dr. O. 

 Beccari, has devoted a large portion of a long and laborious 

 life to the study of Asiatic palms, both in the forest and in 

 the herbarium, and has contributed much to the literature 

 of the subject. Foremost in his work is the monograph of 

 the genus Calamus, noticed in some detail in the Gardeners' 

 Chronicle, Vol. XLVI (1909), p 87, and forming the 

 twelfth volume of \}x& Annals of the Calcutta Botanic Garden. 

 The magnificent illustrations, reproductions of the author's 

 own photographs, constitute the valuable feature of these 

 monographs. They are portraits of specimens preserved in 

 various herbaria, but largely in Beccari's own herbarium, 

 and they include the types or co types of most of the species. 

 The advantage of having these types brought together in one 

 volume is obvious. In Beccari's monograph each species is 

 very fully described in English, to which is added all par- 

 ticulars of its affinities, distribution, uses, and native 

 or trade names. Approximately 200 species of Calamus are 

 known as against somewhat fewer than 100 of Daem- 

 onorops. Some authors regard Daemonorops as a section 

 of Calamus, and there certainly is no character by which 

 the one genus can at once be distinguished from the 

 other. Dr. Beccari states that they are not separable 

 by any character easily explained, but by combinations 

 of characters not repeated in the two genera, and he 

 gives the characteristics, positive and negative, side by side. 

 As to the cultivated species of both genera, he says that 

 they are mostly under incorrect names, and there are also 

 names on record of species which have disappeared from 

 cultivation; names which must remain nuniina nuda for all 

 time. The geographical area of Daemonorops is much 

 more restricted than that of Calamus, and is comprised 

 between Latitude 10°S and 25°X., and between Longitude 

 8.5° and 132° E, with much the greatest concentration of 

 species in the Malayan Peninsula and Archipelago, though no 

 species has been found in New Guinea. Calamus extends to 

 the western peninsula of India and to tropical Africa 



