Permopsocids are small acercarian insects with mouthparts specialized for sucking. They are closely related to Hemiptera and Thysanoptera. The earliest known representatives are from the Early Permian. Here evidence is presented that the Permopsocida occurred even earlier in Pennsylvanian (Moscovian) deposits in the Piesberg quarry near Osnabrück (Lower Saxony, Germany). This material is assigned to the Permian family Psocidiidae; Carbonopsocus mercuryi gen. et sp. nov., based on the wing venation diagnosed by the unique branching pattern of the main veins, the shape of the areola postica being longer than wide, the angular shape of the pterostigma, the ir crossvein directed proximally mid of pterostigma (apomorphy) and the vannus formed by the three veins of PCu, A1 and A2. The shape of the veins, with a Y-vein formed by the distal fusion of PCu with A1, could be a putative symplesiomorphy of the Psocodea with Permopsocida and Hemiptera. C. mercuryi gen. et sp. nov. is the first appearance date for Permopsocida and roots the Acercaria tree. In addition, another specimen of Dichentomum cf. arroyo (Psocidiidae) from Carrizo Arroyo is presented and figured, confirming the presence of the genus Dichentomum near the Carboniferous-Permian boundary and linking it to the Artinskian species from Elmo in Kansas, USA.
- Klíčová slova
- Acercaria, Insecta, Pennsylvanian, Permian, Psocidiidae, Wing venation,
- MeSH
- hmyz * anatomie a histologie MeSH
- křídla zvířecí * anatomie a histologie MeSH
- zkameněliny * anatomie a histologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Německo MeSH
The large abundance of termites is partially achieved by their defensive abilities. Stylotermitidae represented by a single extant genus, Stylotermes, is a member of a termite group Neoisoptera that encompasses 83% of termite species and 94% of termite genera and is characterized by the presence of the frontal gland. Within Neoisoptera, Stylotermitidae represents a species-poor sister lineage of all other groups. We studied the structure of the frontal, labral and labial glands in soldiers and workers of Stylotermes faveolus, and the composition of the frontal gland secretion in S. faveolus and Stylotermes halumicus. We show that the frontal gland is a small active secretory organ in soldiers and workers. It produces a cocktail of monoterpenes in soldiers, and some of these monoterpenes and unidentified proteins in workers. The labral and labial glands are developed similarly to other termite species and contribute to defensive activities (labral in both castes, labial in soldiers) or to the production of digestive enzymes (labial in workers). Our results support the importance of the frontal gland in the evolution of Neoisoptera. Toxic, irritating and detectable monoterpenes play defensive and pheromonal functions and are likely critical novelties contributing to the ecological success of these termites.
- Klíčová slova
- Frontal gland, Labial glands, Labral gland, Microscopy, Termite, Terpenes,
- MeSH
- feromony metabolismus MeSH
- Isoptera * MeSH
- monoterpeny metabolismus MeSH
- švábi * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- feromony MeSH
- monoterpeny MeSH
The soil-feeding habit is an evolutionary novelty found in some advanced groups of termites. The study of such groups is important to revealing interesting adaptations to this way-of-life. The genus Verrucositermes is one such example, characterized by peculiar outgrowths on the head capsule, antennae and maxillary palps, which are not found in any other termite. These structures have been hypothesized to be linked to the presence of a new exocrine organ, the rostral gland, whose structure has remained unexplored. We have thus studied the ultrastructure of the epidermal layer of the head capsule of Verrucositermes tuberosus soldiers. We describe the ultrastructure of the rostral gland, which consists of class 3 secretory cells only. The dominant secretory organelles comprise rough endoplasmic reticulum and Golgi apparatus, which provide secretions delivered to the surface of the head, likely made of peptide-derived components of unclear function. We discuss a possible role of the rostral gland of soldiers as an adaptation to the frequent encounter with soil pathogens during search for new food resources.
- Klíčová slova
- Class 3 secretory cell, Exocrine organ, Isoptera, Proteinaceous secretion, Termites,
- MeSH
- biologická evoluce MeSH
- epidermis MeSH
- Isoptera * ultrastruktura MeSH
- švábi * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Machadotermes is one of the basal Apicotermitinae genera, living in tropical West Africa. Old observations suggested the presence of a new gland, the intramandibular gland, in Machadotermes soldiers. Here, by combining micro-computed tomography, optical and electron microscopy, we showed that the gland exists in Machadotermes soldiers only as an active exocrine organ, consisting of numerous class III cells (bicellular units made of secretory and canal cells), within which the secretion is produced in rough endoplasmic reticulum, and modified and stored in Golgi apparatus. The final secretion is released out from the body through epicuticular canals running through the mandible cuticle to the exterior. We also studied three other Apicotermitinae, Indotermes, Duplidentitermes, and Jugositermes, in which this gland is absent. We speculate that the secretion of this gland may be used as a general protectant or antimicrobial agent. In addition, we observed that the frontal gland, a specific defensive organ in termites, is absent in Machadotermes soldiers while it is tiny in Indotermes soldiers and small in Duplidentitermes and Jugositermes soldiers. At last, we could also observe in all these species the labral, mandibular and labial glands, other exocrine glands present in all termite species studied so far.
- Klíčová slova
- Class III secretory cell, Exocrine organ, Isoptera, Mandibles, Soldier caste, Termites,
- MeSH
- exokrinní žlázy ultrastruktura MeSH
- Isoptera * ultrastruktura MeSH
- rentgenová mikrotomografie MeSH
- švábi * MeSH
- transmisní elektronová mikroskopie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The numerous fossil specimens described as consecutive series of different larval stages of two species, Tchirkovaea guttata and Paimbia fenestrata (Palaeodictyoptera: Tchirkovaeidae), were reinvestigated with emphasis on comparing the development and growth of their wings with that of the wings of a recent mayfly, Cloeon dipterum. This unique fossil material was for a long time considered as undisputed evidence for an unusual type of wing development in Palaeozoic insects. The original idea was that the larvae of Palaeodictyopterida had wings, which were articulated and fully movable in their early stages of postembryonic development and that these gradually enlarging wings changed their position from longitudinal to perpendicular to the body axis. Moreover, the development of wings was supposed to include two or more subimaginal instars, implying that the fully winged instars moulted several times during their postembryonic development. The results of the present study revealed that there is no evidence that this series of nymphal, subimaginal and imaginal wings provide support for the original idea of wing development in Palaeozoic insects. On the contrary, our results indicate, that the supposed palaeodictyopteran larval wings are in fact wing pads with a wing developing inside the cuticular sheath as in recent hemimetabolous insects. Moreover, this study newly reinterpreted the wing pad base of Parathesoneura carpenteri and confirmed the presence of nygma like structures on wings and wing pads of palaeodictyopteran Tchirkovaeidae.
- Klíčová slova
- Ephemeroptera, Insecta, Palaeodictyopterida, Palaeoptera, Postembryonic development, Wing tracheae and lacunae,
- MeSH
- Ephemeroptera * MeSH
- hmyz MeSH
- křídla zvířecí * MeSH
- nymfa MeSH
- zkameněliny MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Pyrrhocoroidea represents an important group of true bugs (Insecta: Hemiptera: Heteroptera) which includes fire bugs, cotton stainers and other taxa widely used in experimental studies or known as pests. However, the morphology and phylogeny of Pyrrhocoroidea have been only poorly studied so far. Here, structures of the external scent efferent system of the metathoracic scent glands are examined in 64 out of 71 currently valid genera of Pyrrhocoroidea and scanning electron micrographs are provided for most taxa. Several characters are revealed which define each of the three higher taxa within Pyrrhocoroidea: Larginae (small auriculate peritreme lacking manubrium and median furrow; metathoracic spiracle never surrounded by evaporatorium), Physopeltinae (large, widely open ostiole; large peritremal disc with manubrium [new term], lacking median furrow; mace-like mycoid filter processes of equal shape and size on both anterior and posterior margins of metathoracic spiracle), and Pyrrhocoridae (elongate auriculate peritreme with deep median furrow). Within Pyrrhocoridae, three main types (A, B and C) of the external scent efferent system are distinguished, differring in the amount of reductions. The findings are interpreted in the context of phylogenetic hypotheses available for Pyrrhocoroidea and their close relatives, Coreoidea and Lygaeoidea. An updated identification key to the families and subfamilies of Pyrrhocoroidea applicable for both sexes is provided.
- Klíčová slova
- Comparative morphology, Eutrichophora, Insect thorax, Phylogeny, Scanning electron microscopy, Spiracle,
- MeSH
- feromony MeSH
- fylogeneze MeSH
- Heteroptera * MeSH
- pachové žlázy MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- feromony MeSH
Trilobites represent a model for 'evo-devo' studies in fossil euarthropods, owing to a rare developmental trait: the biomineralization of the dorsal exoskeleton soon after hatching. Many fossilized trilobite ontogenies thus feature early stages - the protaspides - characterized by non-articulated, calcified dorsal exoskeletons. The recent discovery of a protaspid-like fossil occurring with aglaspidid remains in Middle Ordovician strata of Siberia has been interpreted as evidence for the presence of protaspides in these distant relatives of trilobites. In this contribution, we demonstrate that this Siberian protaspis actually belongs to the asaphid trilobite Isotelus (or a related taxon), a genus likely present in the same bed. We conclude that protaspid larvae still represent a developmental trait unique to Trilobita.
- Klíčová slova
- Aglaspidida, Euarthropoda, Larval ecology, Ordovician, Protaspis, Trilobita,
- MeSH
- členovci * MeSH
- larva MeSH
- zkameněliny MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
External male genitalia of insects are greatly diverse in form and frequently used in evolutionary context and taxonomy. Therefore, our proper recognition of homologous structures among various groups from Paleozoic and extant insect taxa is of crucial interest, allowing to understand the key steps in insect evolution. Here, we reveal structural details of two Late Carboniferous representatives of Megasecoptera (families Bardohymenidae and Brodiopteridae), such as the presence of separated coxal plates VIII and ventral expansions of coxal lobes IX. Together with the confirmed presence of abdominal styli in some other members of Palaeodictyopterida (Diaphanopterodea) this suggests that early pterygotes may have had traits more archaic than expected. Whether or not these traits point to a stem-group relationship of Palaeodictyopterida to all other Pterygota as suspected by earlier authors remains unclear at this stage. Furthermore, the present study provides an updated comparison of male postabdomen morphology among extant species of wingless Archaeognatha and representatives of early diverging groups of Pterygota from the Late Carboniferous and Early Permian, the Megasecoptera (Palaeodictyopterida), Permoplectoptera (Ephemeroptera) and Meganisoptera (Odonatoptera).
- Klíčová slova
- Archaeognatha, Comparative morphology, Insecta, Male genitalia, Palaeodictyopterida, Pterygota,
- MeSH
- biologická evoluce * MeSH
- břicho MeSH
- hmyz anatomie a histologie MeSH
- Pterygota anatomie a histologie MeSH
- zkameněliny anatomie a histologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Cicadas and many of their relatives (Hemiptera: Cicadomorpha) generate vibroacoustic signals using tymbal organs located on their first two abdominal segments. Although tymbals are well-studied in Cicadidae, their systematic distribution in other Cicadomorpha and their possible homologies to the vibroacoustic mechanisms of other Hemiptera have been debated for more than a century. In the present study, we re-examine the morphology of the musculoskeletal system of cicadomorphan vibroacoustic organs, and we document their systematic distribution in 78 species drawn from across the phylogeny of Cicadomorpha. We also compare their morphology to the recently-described snapping organ of planthoppers (Fulgoromorpha). Based on the structure and innervation of the metathoracic and abdominal musculoskeletal system, we find that several key elements of cicadomorphan vibroacoustic organs that have previously been assigned to the first abdominal segment in fact belong to the second. We find that tymbal organs are nearly ubiquitous in Cicadomorpha, and conclude based on their phylogenetic distribution, that they are likely to be synapomorphic. The unusual tymbal-like organs of the Deltocephalinae and Typhlocybinae, represent derived modifications. Finally, we propose a standardised terminology for sternal components of the cicadomorphan vibrational organs, which can be used in future taxonomic descriptions.
- Klíčová slova
- Auchenorrhyncha, Bioacoustics, Biotremology, Snapping organ, Tymbal, Tymbalia,
- MeSH
- biologická evoluce MeSH
- fylogeneze MeSH
- Hemiptera anatomie a histologie fyziologie MeSH
- vokalizace zvířat * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Megasecoptera is a late Paleozoic order of herbivorous insects with rostrum-like mouthparts and slender homonomous outstretched wings. Our knowledge of their morphology is mainly based on wings while other body parts are scarcely documented. Here we focus on the families Bardohymenidae and Aspidothoracidae. A new well preserved specimen of Sylvohymen cf. sibiricus is described and illustrated, particularly the structures of the external male genitalia previously unknown for Bardohymenidae. Sylvohymen marginatussp. nov. is described from the early Permian of Tshekarda based on unique traits in the wing venation. The genera Paleohymen and Taigahymen are both removed from Bardohymenidae and the latter is transferred to Vorkutiidae. Alexahymen aestatis (Brauckmann, 1991) comb. nov. from Pennsylvanian at Piesberg is transferred from Aspidothoracidae to Bardohymenidae. Piesbergbrodiagen. nov. is designated for Piesbergbrodia tristrata (Brauckmann and Herd, 2003) comb. nov. as a member of Brodiidae and the first known record of this family from Piesberg quarry. The placement of Sylvohymen peckae in the Bardohymenidae is considered doubtful due to lack of significant characters in its venation. Furthermore, our study is focused on the form of the apical cell and the pattern of wing pigmentation. Peculiarities of the integumental outgrowths and external genitalia of representatives of Aspidothoracidae and Bardohymenidae, and other close relatives, are highlighted.
- Klíčová slova
- External genitalia, Insecta, Mischopterida, New species, Systematics, Wing venation,
- MeSH
- hmyz anatomie a histologie klasifikace MeSH
- končetiny anatomie a histologie MeSH
- křídla zvířecí anatomie a histologie MeSH
- mužské pohlavní orgány anatomie a histologie MeSH
- zkameněliny anatomie a histologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
