The architecture of the anterior appendage in the egg of the assassin bug,Zelus longipes (Hemiptera : Reduviidae)

The eggshell of Zelus longipes, a Hemiptera species of the family Reduviida e (assassin bugs), has been studied using Scanning Electron Microscopy (SEM ). The emphasis was on the architecture of an anterior appendage connected to the main eggshell of both ovarian and deposited eggs. The analysis of eg gs fractured at various angles and levels reveals a relatively complex orga nization of this appendage. There is a cylindrical outer layer, the veil, o f roughly the same diameter as, and continuous with, the main eggshell. At its anterior pole, the veil folds inwards and forms an hourglass-shaped tub e that is attached through slender er;tensions to a curved plate oriented a t right angles to the long axis of the egg and spanning the internal diamet er of the veil. The plate is solid at the center, shows honeycomb-shaped pe rforations in its mid-section and contains a very, delicate: meshwork along its circumference. Underneath the plate lies a hollow cylinder oriented at right angles to the long axis of the egg and attached to the anterior plat e of the egg, the operculum. The outer openings of aeropyles lie at the inn er face of the veil and at its base. While the outer surface of the entire eggshell appears smooth, the inner face of the anterior appendage is highly and diversely sculptured. The eggs are deposited in batches of at least 15 and completely surrounded by viscous secretion. This substance does not en croach on the anterior appendage. The major function of this appendage may lie in the protection of the aeropyles and particularly in preventing their being clogged by the viscous material. (C) 2001 Elsevier Science Ltd. All rights reserved.