Silkworm Egg Farming

the production of healthy, viable silkworm eggs from the moths of the Chinese silkworm and the lappet moth in special sericultural breeding stations and egg hatcheries.

The main problem of breeding silkworms from eggs is in controlling the silkworm diseases (mainly pébrine) that are transmitted by infected eggs. In the USSR sericultural stations produce eggs from pure strains of the Chinese silkworm and transfer them to sericultural farms, which rear the caterpillars and prepare the purebred elite egg stock for transfer to the hatcheries. Allotted to every egg hatchery is an area in whose sericultural farms the silkworm caterpillars are raised from elite or purebred eggs of various categories. The breeding farms supply the hatcheries with cocoons, which, after careful checkup, microscopic examination of samples for pébrine, and qualitative evaluation of each batch, are used for hatching the moths and obtaining the eggs. The egg hatcheries usually work with commercial hybrid eggs, which are put through regional bureaus that stock the cocoons for the farms in order to obtain “commercial” cocoons—the raw material for the production of silk.

Purebred eggs are produced in the USSR only by the cellular method, which guarantees that the eggs will be uninfected. By this method, the female moths are isolated (after mating) in small paper sacs, where they then lay their eggs. The moths are then examined microscopically in order to expose those infected with pébrine; the diseased moths, together with the eggs they have laid, are destroyed. The eggs from the healthy females are combined, washed, and weighed out in small paper sacs (at 25 grams each in the RSFSR and 29 grams in the Uzbek SSR), each of which constitutes a so-called hamper; these are refrigerated until the following spring. Commercial eggs are produced by less labor-consuming means (the commercial, biological, thermal, and V. A. Strunnikov methods); however, if pébrine infection is present, they are produced by the cellular method. The mass of prepared eggs should be hybrid; the eggs of pure breeds are used mainly for the preparation of hybrids. In countries with highly developed sericulture, such as Japan, the People’s Republic of Korea, and Italy, purebred eggs are prepared by the cellular method and commercial eggs, by the commercial method.

Before the October Revolution more than 70 percent of the silkworm eggs were imported to Russia from abroad; however, the USSR has a highly developed silkworm egg industry: in 1971 there were 39 silkworm egg hatcheries and five sericultural breeding stations preparing the eggs of the Chinese silkworm and concentrated in Middle Asia, the Transcaucasus (the principal sericultural regions of prerevo-lutionary Russia), the RSFSR, the Ukraine, and Moldavia.