Changes in the Distribution of Nitrogen during the Embryonic Development of the Japanese Beetle (Popillia japonica Newman)

Abstract

Detns. were made of the nitrogen in the alcohol-ether-soluble (A), water and tungstic acid-soluble (B), water-soluble but tungstic acid-insoluble (C), and water insoluble fractions of Japanese beetle eggs for each day of development at 30[degree]C. At this temp. embryogenesis requires 8 days. The nitrogen for each fraction, expressed as % total N, varied as follows. In fraction A it increased from an initial value of 1.8 to 11.2 in the 3-day egg. It then decreased regularly to 7.2 in the newly hatched larva. In fraction B, it increased from 4.0 to 9.1 during the first 3 days and then remained constant during the remainder of the embryonic period. An increase to 15.3 was found in the newly hatched larva. In fraction C, it decreased rapidly during the first 4 days, then more slowly during the remainder of the embryonic period. Its value was 81.4 in the newly laid egg; just before hatching, it was 10.0. The change in fraction D was opposite to that in fraction C. Its initial value was 12.9; just before hatching, it was 71.8. A loss to 66.4 occurred at eclosion.