CHAPTER VII. CLASS 76.-USEFUL AND INJURIOUS INSECTS. BY C. L. MARLATT. Bees and silkworms. Cochineal insects. Apparatus used in the culture and keeping of bees and silkworms. I. SERICICULTURE. The number of persons engaged in producing silkworm eggs or the amount of eggs produced is not so good a criterion of real progress in sericiculture as is the average number of kilos of cocoons produced by an ounce* of eggs. In France this yield has increased from 13.4 kilos per ounce in 1862 to 36.4 kilos in 1888, though during the time there was a decrease in the amount of eggs hatched, one factor having increased while the other diminished. The total yield has remained nearly constant, as the following table will show :' In 1874 the competition of Eastern silk arriving via the Suez Canal caused a ruinous fall of prices throughout Europe, and in France a kilo of cocoons, which from 1862 to 1874 brought 6.70 francs, would thereafter only bring 5 francs, which price gradually fell to 3.50 francs in 1888. The consequent loss to silkworm raisers was very great, so that while in 1872 there were 200,000 families supported by this industry in 1888 this number had fallen to 143,000. Another reason for this decrease is that the new process of breeding requires careful education and training, which many persons are too poor, too busy, or too ignorant to acquire. *An ounce of silkworm eggs weighs 25 grams in the department of Basses Alpes, but 30 grams elsewhere in France. Japanese silkworm eggs were first imported into France in 1864, and soon supplanted the eggs of native races to such an extent that in 1869 they formed 70 per cent of the whole. In 1872 this proportion had decreased to 61 per cent, and in 1882 to less than 4 per cent, this last diminution being caused by the rehabilitation of the native races through Pasteur's system, which has proved to be the salvation of French sericiculture. In 1883 France again commenced to export silkworm eggs, about 200,000 ounces being yearly sent to Turkey, Greece, Hungary, Spain, and Italy. In 1857 the mulberry trees of France afforded 600,000 tonnes of leaves annually; but, the trees having been neglected, many have perished, so that at the present time it would be difficult to procure 250,000 tonnes. In short, France does not now produce as many silkworms, and has not as many mulberry trees as formerly, though she produces proportionately more cocoons, and the eggs produced are of better quality. The benefits, however, which arise from this intensive culture do not counterbalance the loss resulting from the decrease of the industry. There were some twenty exhibits made by French sericiculturists, foremost among whom should be mentioned the late M. Eugène Mailot, director of the sericicultural station at Montpellier. He displayed a large sericicultural map of France, and has also issued (1886) a pamphlet giving statistics of this industry. It is to his notes, used before the International Agricultural Congress and those made by Prof. Riley and Mr. Amory Austin that I am indebted for much important data in preparing this report. From Maillot's statistical tables it is shown that during the three years 1882-'84 silkworms were raised in 24 of the departments of France. Of these departments, Gard, Ardèche Drôme, and Vaucluse were the most important, in order, and together raised over 80 per cent of the total amount of silkworms, while six other departments each raised from 100,000 to 300,000 kilos of cocoons, the remaining 10 departments being less important in this respect. The average annual product of the whole of France during these three years was 7,936,215 kilos of cocoons, of which 260,000 were green cocoons of foreign origin. 1 There are four departments in which the production of silkworm eggs is more important than the production of cocoons, namely Var, Basses Alpes, Corsica, and Pyrénées Orientales. A comparative table is here given. France Austria-Hungary Spain. According to statistics published by the syndicate of silk merchants of Lyons the average annual quantity of raw silk brought to European markets in 1882-'84 was: Kilos. 622,000 2,793, 000 149,000 96,000 M. Chauvet, of Buis (Drôme), displayed an interesting collection of cocoons of various races, and also those resulting from the crossbreeding between the Gros-Var and Gros Riom races, Var and Bagdad. M. Forné, of Céret (Pyrénées Orientales), showed cocoons and eggs of various races, among others the large cocoons of the Fossombrone race, which are used especially in making the product known as cru de Florence. The exhibit of M. Fallou, of Paris, was devoted to exotic races and was incomparably better than any other showing in the same class. M. Fallou has for years and with remarkable patience conducted experiments in sericiculture, in the effort to discover and introduce new races and species of silk insects. Three among these only have proved of any practical value in French industry, namely, the Attacus cynthia, from China, and the Antheraea pernyi, also from China, and the Attacus yamamaï, from Japan. The first of these, A. cynthia, has become so well acclimated in France that it has almost reverted to the wild state, and may be found upon the Ailanthus trees in public parks or along the avenues in cities, just as in the United States. It was also shown at the Exposition of 1878, but its open cocoon renders it difficult of use, not withstanding M. LeDoux's ingenious process of winding such cocoons, so that it may be considered as lost to French industry. The bivoltinism of the Antheraea offers a serious obstacle to its acclimatization in France, since the falling of the leaves from the oak trees does not always allow time for the complete development of the second generation. This disadvantage does not exist in the case of Attacus yamamai the silk of which is of a very superior quality and was also exhibited in France as early as 1878. Although, perhaps, practice and experience will bring better results, the breeding of this species, as well as that of the others, will probably remain in the hands of amateurs. M. Fallou has succeeded in raising certain races, notably the Antheræa, Telea polyphemus, Attacus ceropia, etc., in the open air at his nurseries in Seine-et-Oise. The other French exhibits consisted of eggs, cocoons, etc., of native races, large anatomical models of silkworms, raw silk, etc., the whole making a moderately large and interesting display. ALGERIA. Hardly any attention whatever is given to sericiculture in this country, although silkworms do remarkably well throughout the Tell. The production is, however, increasing, and from 1875 to 1880 the increase in the total amount of cocoons was from 5,300 to 139,000 kilos. There were five exhibitors from Algeria showing cocoons and eggs produced by the cellular system. The races of Algeria have no special characteristics, but are derived from French races. ITALY. There was but a single exhibitor from this country, Sig. Marconi, of Cremona, who showed new apparatus for producing eggs by the cellular system devised by Pasteur. His method consists of using small bags of perforated parchment or paper, or of small boxes covered with gauze, and does not seem to present any particular advantages over the bags of gauze ordinarily employed. Italy stands incontestably at the head of all the European states in sericiculture, as the following figures show: The importance of this production is due, not only to the extent of breeding, but to the perfection of the methods in use; the principles of cellular breeding are vigorously applied and the yield of sound eggs is considerable in consequence. The following shows the kilos of cocoons per each ounce of eggs, the ounce weighing 28 grams: 1878.... 1883. 15.3 23.7 29.0 In 1883 the yield in kilos of cocoons per ounce of eggs in certain provinces was as follows: Pesaro Macerata. 59.9 54.9 48.4 In Italy the only variety of silkworm formerly raised was that with yellow cocoons, but during the prevalence of the silkworm disease eggs of the Japanese race having green cocoons were introduced. At present native races are preferred, and their use has greatly increased in the last few years. The following shows the per cent of yellow or native cocoons: Belgium sent one exhibit, that of Mme. Fuisseau of Brussels, who showed cocoons, apparatus for rearing silkworms, material for teaching the art, and several books and pamphlets upon the subject. No new facts were brought out by this exhibit, which was similar to that made in 1878. The Belgian Government has for many years attempted to encourage sericiculture, but without success, and the industry is practically of no importance in that country. Great Britain exhibited a few cocoons from Cashmere. The other European States made no exhibits whatever in sericiculture. A table of their average annual production is, however, here given : This country made a most interesting exhibit of its silk-culture under the auspices of the minister of agriculture and commerce and of the agricultural and forestry school at Komaba. About 30 races of the silkworm, Sericaria mori, are common in |