. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 12 just before tiie egg is deposited by the female. After fecinidation and before deposition the egg of some varieties is covered with a gummy varnish which closes the micropyle and serves to stick the egg to the object upon which it is hiid. Other varieties, however, among which may be mentioned the Adrianople whites and the yellows from Nouka, in the Caucasus, have not this natural gum. As the hatching point approaches the egg becomes lighter in color, which is due to the fact that its fluid contents become con
. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 12 just before tiie egg is deposited by the female. After fecinidation and before deposition the egg of some varieties is covered with a gummy varnish which closes the micropyle and serves to stick the egg to the object upon which it is hiid. Other varieties, however, among which may be mentioned the Adrianople whites and the yellows from Nouka, in the Caucasus, have not this natural gum. As the hatching point approaches the egg becomes lighter in color, which is due to the fact that its fluid contents become concentrated, as it were, into the central forming worm, leaving an intervening space between it and the shell, which is semi-transparent. Just before hatching, the worm within be- coming more active, a slight clicking sound is frequently heard, which sound is, however, common to the eggs of many other insects. The shell becomes quite white after the worm has made its exit by gnawing a hole through it, which it does at the micropyle. Each female pro- duces on an average from three to four hundred eggs. In the standard ounce of 25 grams* there are about 50,000 eggs of the small Japanese races, 37,500 of the ordinary yellow annual varieties, and from 30,000 to 35,000 in the races with large cocoons. The specific gravity of the eggs is slightly greater than water, Haberlandt having placed it at It has been noticed that the color of the albuminous fluid of the egg (Corresponds to that of the cocoon, so that when the fluid is white the cocoon produced is also white, and when yellow the cocoon again cor- responds. The Larva or Worm.—The worm goes through from three to four. Fig. 1.—Full gro\7n larva or worm (after Riley). molts or sicknesses, the latter being the normal number. The periods between these ditterent molts are called " ages," there being five of these ages, the first extending from the time of hatching to the end of the first molt, and the last from the
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