Zoological Museum of Moscow State University, Bolshaya Nikitskaya 6, Moscow 103009, Russia

Abstract

Head of insects is the most integrative part of the body according to the level of segment confluence. Capsule and skeleton of appendages _ antennas, mandibles, labrum, maxillolabial complex _ are distinguished in the head skeleton. Capsule, its exo- and endoskeleton (tentorium) have complex segmental structure. There are not distinct boundaries between parts of exoskeleton _ clypeus, frons, vertex, occiput, genae, etc. They can be distinguished only relatively to the position of appendages, eyes, complex eyes, occipital foramen, mouse fossa. Homologization of these exoskeleton parts is difficult because they do not have any functional meaning and distinct segmental origin. The author characterizes the structure of Aculeata capsule from technological point of view. Parts of capsule are considered as components of six technological systems connected with the head skeleton: maxillolabial, antennal, pharyngeal, optical, cranio-articulate and mandibular. The systems are united by spatial connections (topographic coordinates according to I.I.Schmalhausen) and so mutual location of capsule parts connected with them are kept during any reorganization. Changes of their form and topography are reflected on the form and topography of exoskeleton and capsule tentorium. Capsule structure was analyzed in Bethyloidea, Formicoidea, Sphecoidea, Vespoidea, Pompiloidea and Scolioidea. It was shown that many differences are caused by connected reorganization of technological systems rousing parallel changes of several functions at once. For example, the increase in head mobility connected with cranio-articulate system correlates with displacement of antennas to the front part of the head. The author distinguishes hypognathal, prognathal and hypo-prognathal morphotypes of Aculeata capsule that determine the head position relatively to longitudinal axis of the body. The role of topographical co-ordinations in formation of pro- and hypognathal complex of characters is discussed.