RESUMO
Tok-tokkies are one of the most iconic lineages within Tenebrionidae. In addition to containing some of the largest darkling beetles, this tribe is recognized for its remarkable form of sexual communication known as substrate tapping. Nevertheless, the phylogenetic relationships within the group remain poorly understood. This study investigates the usefulness of female terminalia morphology for delimiting Sepidiini and reconstructing relationships among it. Data on the structure of the ovipositors, genital tubes and spicula ventrali have been generated for >200 species representing 28 Pimeliinae tribes. This dataset was used in a comparative analysis at the subfamilial level, which resulted in recognition of several unique features of tok-tokkie terminalia. Additionally, new features linking phenotypically challenging tribes also were recovered (Cryptochilini + Idisiini + Pimeliini). Secondly, 23 characters linked to the structure of female terminalia were defined for tok-tok beetles. Cladistic analysis demonstrates the nonmonophyletic nature of most of the recognized subtribes. The morphological dataset was analysed separately and in combination with available molecular data (CAD, Wg, cox1, cox2, 28S). All obtained topologies were largely congruent, supporting the following changes: Palpomodina Kaminski & Gearner subtr.n. is erected to accommodate the genera Namibomodes and Palpomodes; Argenticrinis and Bombocnodulus are transferred from Hypomelina to Molurina; 153 species and subspecies previously classified within Psammodes are distributed over three separate genera (Mariazofia Kaminski nom.n., Piesomera stat.r., Psammodes sens.n.). Psammodes sklodowskae Kaminski & Gearner sp.n. is described. Preliminary investigation of the ovipositor of Mariazofia basuto (Koch) comb.n. was carried out with the application of microcomputed tomography, illuminating the muscular system as a reliable reference point for recognizing homologous elements in highly modified ovipositors.
Assuntos
Besouros , Animais , Feminino , Filogenia , Microtomografia por Raio-X , Sorogrupo , GenitáliaRESUMO
The tracheal (respiratory) system is regarded as one of the key elements which enabled insects to conquer terrestrial habitats and, as a result, achieve extreme species diversity. Despite this fact, anatomical data concerning this biological system is relatively scarce, especially in an ontogenetic context. The purpose of this study is to provide novel and reliable information on the post-embryonic development of the tracheal system of holometabolous insects using micro-computed tomography methods. Data concerning the structure of the respiratory system acquired from different developmental stages (larvae, pupae and adults) of a single insect species (Tenebrio molitor) are co-analysed in detail. Anatomy of the tracheal system is presented. Sample sizes used (29 individuals) enabled statistical analysis of the results obtained. The following aspects have been investigated (among others): the spiracle arrangement, the number of tracheal ramifications originating from particular spiracles, the diameter of longitudinal trunks, tracheal system volumes, tracheae diameter distribution and fractal dimension analysis. Based on the data acquired, the modularity of the tracheal system is postulated. Using anatomical and functional factors, the following respiratory module types have been distinguished: cephalo-prothoracic, metathoracic and abdominal. These modules can be unambiguously identified in all of the studied developmental stages. A cephalo-prothoracic module aerates organs located in the head capsule, prothorax and additionally prolegs. It is characterised by relatively thick longitudinal trunks and originates in the first thoracic spiracle pair. Thoracic modules support the flight muscles, wings, elytra, meso- and metalegs. The unique feature of this module is the presence of additional longitudinal connections between the neighbouring spiracles. These modules are concentrated around the second prothoracic and the first abdominal spiracle pairs. An abdominal module is characterised by relatively thin ventral longitudinal trunks. Its main role is to support systems located in the abdomen; however, its long visceral tracheae aerate organs situated medially from the flight muscles. Analysis of changes of the tracheal system volume enabled the calculation of growth scaling among body tissues and the volume of the tracheal system. The data presented show that the development of the body volume and tracheal system is not linear in holometabola due to the occurrence of the pupal stage causing a decrease in body volume in the imago and at the same time influencing high growth rates of the tracheal system during metamorphosis, exceeding that ones observed for hemimetabola.
Assuntos
Besouros/anatomia & histologia , Besouros/crescimento & desenvolvimento , Traqueia/anatomia & histologia , Traqueia/crescimento & desenvolvimento , AnimaisRESUMO
The genus Helibatus consists of two species: H. morio Mulsant & Rey, 1859 and newly described H. banaszkiewiczae sp. nov. The species differ from each other in the structure of the metaventral process. The genus is distributed in Southern Africa--a distribution map for the two known species is provided.
Assuntos
Besouros/anatomia & histologia , Besouros/classificação , Animais , Feminino , Masculino , África do Sul , Especificidade da EspécieRESUMO
A second species of the genus Kochogaster Kaminski et Ras (K. gerardi sp. n.) is described from the surroundings of Garissa (Kenya). The taxonomic concept and phylogenetic relationships of Kochogaster are discussed. A distributional map is presented with complete faunistic data on the genus. Additionally, the original spelling of the name Anchophthalmus inuelleri Schimrosczyk, 2010 is emended to A. muellerae due the rules of the International Code of Zoological Nomenclature.
Assuntos
Besouros/classificação , Besouros/ultraestrutura , Distribuição Animal , Animais , Feminino , Quênia , Masculino , Especificidade da EspécieRESUMO
The tracheal system comprises one of the major adaptations of insects towards a terrestrial lifestyle. Many aspects such as the modifications towards wing reduction or a life in an arid climate are still poorly understood. To address these issues, we performed the first three-dimensional morphometric analyses of the tracheal system of a wingless insect, the desert beetle Gonopus tibialis and compared it with a flying beetle (Tenebrio molitor). Our results clearly show that the reduction of the flight apparatus has severe consequences for the tracheal system. This includes the reduction of the tracheal density, the relative volume of the trachea, the volume of the respective spiracles and the complete loss of individual tracheae. At the same time, the reduction of wings in the desert beetle allows modifications of the tracheal system that would be impossible in an animal with a functional flight apparatus such as the formation of a subelytral cavity as a part of the tracheal system, the strong elongation of the digestive tract including its tracheal system or the respiration through a single spiracle. Finally, we addressed when these modifications of the tracheal system take place during the development of the studied beetles. We can clearly show that they develop during pupation while the larvae of both species are almost identical in their tracheal system and body shape.
Assuntos
Besouros , Animais , Traqueia , Respiração , Insetos , AclimataçãoRESUMO
In many extreme arid ecosystems, insects constitute major faunal components and are key contributors in nutrient cycling. Previous research on xerophily in insects has focused on adult forms. This study investigates skeletomuscular and behavioural adaptations of the Kalahari sandworm beetle larvae (Gonopus tibialis Fabricius) for dwelling in the sand. Microcomputed tomography enabled cuticle thickness distribution analysis, revealing structural reinforcements of the mandibular edge, the middle part of the head, and the ventral side of the front legs. Laboratory observations and the analysis of muscular system allowed for the definition and functional description of the elements of the digging apparatus of the sandworm larvae. Obtained results point to the crucial role of the head and mandibles in the digging process. These observations are important for understanding desert ecology and pose a challenge to develop newer excavation techniques.
Assuntos
Besouros , Aclimatação , Animais , Ecossistema , Larva , Microtomografia por Raio-XRESUMO
Based on type specimen investigation, the status of Helops tristis Rossi, 1790 as the type species of the genus Dendarus Dejean, 1821 is confirmed. Lectotypes are designated for Helops tristis and Pandarus coarcticollis Mulsant, 1854 both are classified in Dendarus. Pandarus libanicus Desbrochers des Loges, 1881 is recognised as a junior synonym of Dendarus calcaratus Baudi di Selve, 1881. Both taxa share the same locus typicus (Mount Lebanon in Lebanon) and are morphologically distinct from the Italian Dendarus lugens (Mulsant Rey, 1854). Finally, D. lugens is considered as a synonym of D. (Dendarus) coarcticollis.
Assuntos
Besouros , Copépodes , Distribuição Animal , AnimaisRESUMO
The genus Atrocrates Koch, 1956 belongs to the trigonopoid evolutionary lineage of the subtribe Platynotina, which consists of endemic South African genera. In the present paper, a division of Atrocrates based on the structure of mentum, pronotum, male mid tibiae, elytral humeri into the following species groups is proposed: bellamyi (10 species), bisinuatus (5), capensis (3), coconatae (5), evestigator (4), formosus (2), galbasi (2), occultator (2). An illustrated key to all of the above mentioned species groups is included. Moreover, two news species A. galbasi sp. nov. and A. matthewsi sp. nov. from Southern Africa are diagnosed, described and illustrated.
Assuntos
Besouros/anatomia & histologia , Besouros/classificação , Animais , Feminino , Masculino , África do Sul , Especificidade da EspécieRESUMO
In recent years, µCT-based studies of the insect tracheal system have become an increasingly important area of research. Nevertheless, the methods proposed in previous research for investigating the respiratory system in the three-dimensional space were described and tested based on a relatively small number of specimens. Additionally, the individuals studied in all these cases represented only a single post-embryonic stadium - pupa or imago - of a particular insect species. Therefore, in the current situation it is difficult to predict the reliability and possible limitations of these methods. To address this problem we conducted a methodological study, during which we used 65 individuals representing larvae, pupae and imagines of the mealworm beetle (Tenebrio molitor). In addition to the protocol previously described, which implicated freezing as a killing technique, we also tested a novel one, which was based on ethyl acetate fumigation of the specimens studied. We included step-by-step guides for the manual and semiautomatic approaches in order to facilitate the digital visualization of the tracheal system. Our investigations enabled us to generate multiple models of the tracheal system of all post-embryonic stages of the mealworm beetle. The methods used proved to be minimally invasive, thus allowing for the application of post-scanning manipulations, such as drying with critical point dryer (CPD). This approach enabled us to merge different three-dimensional models into a single picture and analyse the relationship of the tracheal system with other tissues (e.g., muscles, nervous system). We comprehensively discuss the advantages and possible limitations of the tested methods and provide practical suggestions for conducting the analyses on a wider scale. The visualizations presented in this publication are the first three-dimensional models of the respiratory system using a representative of the extremely diverse order Coleoptera.