The Growth-Changes and Structure of the Egg of the African Migratory Locust,<i>Locusta migratoria migratorioides</i>, R. &amp; F. (Orthoptera, Acrididae)

Abstract

The eggs of Locusta migratoria migratorioides , R. &amp; F., increase in size during development. The increase is due to the absorption of water from the surrounding moist soil. The wet weight of a freshly laid egg is 0·0063±0·0008 gms, and of a fully developed egg 0·014±0·002 gms. The dry weight of a freshly laid egg is 0·003± 0·0004 gms. and of a fully developed egg 0·0024±0·0002 gms. The water-content of an egg increases from 51·92±3·53 per cent, of the wet weight in the freshly laid egg to 82·36±2·14 per cent, in the fully developed egg. The egg-wall consists of an exo- and endochorion and a thick vitelline membrane. The latter has a felt-like structure in the freshly laid egg, but as the egg develops, this membrane increases in thickness and acquires a laminated character. The micropylar apparatus consists of a ring of about 35–43 oblique, funnelshaped canals arranged round the egg near its posterior end.