| Abstrakt: |
Simple Summary: The study focuses on the morphological characteristics and sensory structures of the antennae of G. italicum. The results indicate that there is no significant sexual dimorphism in the antennomeres and sensilla equipment. Six main types of sensilla were identified, including basiconic, trichoid, coeloconic, chaetic, campaniform, and peg sensilla. These sensilla were further categorized into subtypes based on their shape, length, and ultrastructure, with evidence supporting their functions as olfactory, thermo–hygroreceptors, and mechanoreceptors. The ultrastructure of the dendritic elements and pore systems of the sensilla, as well as the presence of inflexible/flexible sockets, provided insights into the primary functions of the sensilla. The distribution of sensilla varied across specific antennomeres, with distinct arrangements observed on the scapus, pedicel, basiflagellum, and distiflagellum. The study's findings provide detailed insights into the morphological and functional diversity of the antennal sensory structures in G. italicum, contributing to a comprehensive understanding of sensory perception in this species. The antennae of the shield bug Graphosoma italicum (Müller, 1766) were examined through scanning and transmission electron microscopy to reveal their general morphology, as well as the antennal sensilla's distribution, size, and ultrastructure of their dendrites and function. The antennae comprise five antennomeres (one scape, two pedicels, and two flagellomeres). Different lengths of chaetic mechanosensilla (Ch1-Ch4) exist on all antennomeres, and several highly sensitive campaniform sensilla are embedded in the exoskeleton and measure cuticular strain. One pair of peg sensilla, the typical proprioceptive, is only on the proximal edge of the first pedicel and directed to the distal edge of the scapus. The antennal flagellum possesses two subtypes of trichoid and basiconic sensilla, each with one type of coeloconic olfactory sensilla. The distinctive characteristics of G. italicum are also apparent in two subtypes of coeloconic sensilla embedded in different cavities on both antennomeres of the flagellum, probably with a thermo-hypersensitive function. All studied morphological types of the sensilla and their function were supported by ultrastructural elements. The long and thin trichoid sensilla type 2 (TrS2) with an olfactive function was the most abundant sensilla localized on both flagellomeres. The peripheral antennal sensilla system consists of six main types of sensilla divided into twelve subtypes. [ABSTRACT FROM AUTHOR] |
