The maxillo-labial complex of Sparasion (Hymenoptera, Platygastroidea)

Abstract

Hymenopterans have evolved a rich array of morphological diversity within the maxillo-labial complex. Although the character system has been extensively studied and its phylogenetic implications revealed in large hymenopterans, e.g. in Aculeata, it remains comparatively understudied in parasitoid wasps. Reductions of character systems due to the small body size in microhymenoptera make it difficult to establish homology and limits the interoperability of morphological data. We describe here the maxillo-labial complex of an ancestral platygastroid lineage, Sparasion, and provide an ontology-based model of the anatomical concepts related to the maxillo-labial complex (MLC) of Hymenoptera. The possible functions and putative evolutionary relevance of some anatomical structures of the MLC in Sparasion are discussed. Anatomical structures are visualized with Confocal Laser Scanning Microscopy.

The feeding apparatus of ants: An overview of structure and function

“…General mouthpart structure is similar between ants and related hymenopterans such as vespid [67,68] or sphecid wasps [19,69] and many similarities exist even with more distantly related parasitoid wasps [70]. The most prominent differences of closer relatives such as sphecids are the larger paraglossae, the hair cover of the maxillolabial complex, the proportions and attachment angles of some muscles (especially the labial extensor), and an overall more open condition of the complex, as it is not usually retracted completely behind the labrum [19].…”