Formation and structure of egg capsules in scale insects (Hemiptera, Coccinea) - I. Ortheziidae

The paired ovaries of the investigated species are composed of 20-30 ovario les of a telotrophic-meroistic type. Each ovariole is subdivided into an ap ical tropharium (= trophic chamber) and a vitellarium. that contains a sing le developing oocyte. This oocyte is surrounded by a mono-layered follicula r epithelium that is responsible for synthesis of precursors of egg envelop es. In Orthezia, synthesis and secretion of precursors of egg envelopes ( = choriogenesis) and accumulation of reserve substances in the oocyte cytopl asm ( = vitellogenesis) start at the same time. The egg capsule is composed of two envelopes: an internal, thick vitelline envelope and an external, v ery thin chorion. The egg surface is covered with numerous, irregularly arr anged waxy filaments of spiral shape. Eggs are devoid of the micropylar, ae ropylar and hydropylar openings. (C) 2001 Elsevier Science Ltd. All rights reserved.