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1.
J Insect Sci ; 20(1)2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31925424

RESUMO

Urbanization has a significant impact on abiotic and biotic factors in nature. We examined the morphometric characters of four carabid species (Abax parallelepipedus, Carabus scheidleri, Carabus violaceus, and Pterostichus oblongopunctatus) along urbanization gradients in and around the cities of Vienna (Austria) and Debrecen (Hungary). We found significant differences among urban, suburban, and rural areas in the parameters of antennomers, the maxillary palpus, the labial palpus, and the length of the tibia and the elytra of the carabids studied. We also found significant differences between males and females based on the parameters of antennomers, the maxillary palpus, the labial palpus, the femur, and the elytra. An interaction between urbanization and sex was found in the case of antennomers, the maxillary palpus, the labial palpus, the femur, and the elytra. Our findings suggested that in the cases of species from Carabini tribus the parameters of antennomers, the maxillary palpus, and the elytra could be useful for assessing the effects of urbanization because these morphometric characters responded sensitively to the environmental stress, whereas the most useful parameters are those of antennomers and the tibia for the species of Pterostichini tribus. Our findings also revealed that females are more sensitive to environmental stress than males.


Assuntos
Besouros/anatomia & histologia , Urbanização , Animais , Áustria , Cidades , Feminino , Hungria , Masculino , Especificidade da Espécie
2.
An Acad Bras Cienc ; 91(4): e20180954, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31721919

RESUMO

A new species of Stethelmis, S. shepardi sp. nov., is described for Patagonia, Argentina from adults of both sexes. A full description and illustrations of both the adult and the larva of the new species are provided with comments on its habitat and distribution. Adults of the new species are compared with those of S. kaszabi (Hinton 1970) and S. chilensis (Hinton 1945). The larva of S. shepardi is compared with that of S. kaszabi, the other Stethelmis larva described. We also describe and illustrate for the first time the male genitalia of S. kaszabi. A key to the known species of Stethelmis is also included.


Assuntos
Besouros/anatomia & histologia , Besouros/classificação , Distribuição Animal , Animais , Argentina , Ecossistema , Feminino , Masculino
3.
Nat Commun ; 10(1): 4758, 2019 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-31628305

RESUMO

The outermost surface of insect cuticle is a high-performance interface that provides wear protection, hydration, camouflage and sensing. The complex and inhomogeneous structure of insect cuticle imposes stringent requirements on approaches to elucidate its molecular structure and surface chemistry. Therefore, a molecular understanding and possible mimicry of the surface of insect cuticle has been a challenge. Conventional optical and electron microscopies as well as biochemical techniques provide information about morphology and chemistry but lack surface specificity. We here show that a near edge X-ray absorption fine structure microscope at the National Synchrotron Light Source can probe the surface chemistry of the curved and inhomogeneous cuticle of the African flower scarab. The analysis shows the distribution of organic and inorganic surface species while also hinting at the presence of aragonite at the dorsal protrusion region of the Eudicella gralli head, in line with its biological function.


Assuntos
Escamas de Animais/química , Besouros/química , Espectroscopia por Absorção de Raios X/métodos , Escamas de Animais/anatomia & histologia , Escamas de Animais/ultraestrutura , Animais , Besouros/anatomia & histologia , Besouros/ultraestrutura , Feminino , Flores/parasitologia , Proteínas de Insetos/análise , Proteínas de Insetos/ultraestrutura , Microscopia Eletrônica de Varredura , Propriedades de Superfície , Síncrotrons
4.
Naturwissenschaften ; 106(9-10): 50, 2019 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-31456022

RESUMO

The cavities of bamboos (Poaceae) are used by various animals. Most of the animals access these cavities either by existing cracks or by excavating bamboos with soft walls or small, thin-walled bamboos. Only a few animals excavate into the cavities of large and thick- and hard-walled internodes of mature bamboos. We studied two lizard beetle species (Coleoptera: Erotylidae: Languriinae), Doubledaya ruficollis and Oxylanguria acutipennis, that excavate into large internode cavities of recently dead mature bamboos and have morphological modifications. We observed that females of D. ruficollis used their mandibles to bore oviposition holes on Schizostachyum sp. (mean wall thickness = 3.00 mm) and O. acutipennis did so on Dendrocalamus sp. (3.37 mm) bamboos. Previous studies suggested that the markedly asymmetrical mandibles and needle-like ovipositors of females in the genus Doubledaya are adaptive traits for excavating hard-walled bamboos for oviposition. Therefore, we measured their mandibular lengths and ovipositor lengths. D. ruficollis females had greater asymmetry in the mandibles and shorter and less-sclerotized ovipositors than females of congeners using small bamboos. In contrast, O. acutipennis females had slightly asymmetrical mandibles and elongated, well-sclerotized ovipositors. Oviposition holes of D. ruficollis were cone-shaped (evenly tapering), whereas those of O. acutipennis were funnel-shaped (tube-like at the internal apex). This suggests that D. ruficollis females excavate oviposition holes using the mandibles only, and O. acutipennis females use both the mandibles and ovipositors. These differences suggest different oviposition-associated morphological specialization for using large bamboos: the extremely asymmetrical mandibles in D. ruficollis and elongated, needle-like ovipositors in O. acutipennis.


Assuntos
Besouros/anatomia & histologia , Besouros/fisiologia , Estruturas Animais/anatomia & histologia , Animais , Comportamento Animal/fisiologia , Feminino , Tamanho do Órgão/fisiologia , Poaceae/anatomia & histologia , Poaceae/parasitologia
5.
Ecol Lett ; 22(10): 1629-1637, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31353816

RESUMO

The effect of sexual selection on species persistence remains unclear. The cost of bearing ornaments or armaments might increase extinction risk, but sexual selection can also enhance the spread of beneficial alleles and increase the removal of deleterious alleles, potentially reducing extinction risk. Here we investigate the effect of sexual selection on species persistence in a community of 34 species of dung beetles across a gradient of environmental disturbance ranging from old growth forest to oil palm plantation. Horns are sexually selected traits used in contests between males, and we find that both horn presence and relative size are strongly positively associated with species persistence and abundance in altered habitats. Testes mass, an indicator of post-copulatory selection, is, however, negatively linked with the abundance of species within the most disturbed habitats. This study represents the first evidence from a field system of a population-level benefit from pre-copulatory sexual selection.


Assuntos
Besouros/anatomia & histologia , Comportamento Sexual Animal , Animais , Bornéu , Besouros/fisiologia , Ecossistema , Masculino , Fenótipo
6.
J Insect Sci ; 19(4)2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31340383

RESUMO

The Comal Springs dryopid beetle, Stygoparnus comalensis Barr and Spangler, and the Comal Springs riffle beetle, Heterelmis comalensis Bosse, Tuff, and Brown, are protected by the United States Fish and Wildlife Service (USFWS), and the development of a captive self-propagating refuge is of importance to stakeholders within the Edwards Aquifer. Being able to reliably distinguish the sex of living subjects is desirable for establishing a successful refuge program. Ventrite, elytron, and pronotum measurements of S. comalensis were taken to determine if there were sexually dimorphic allometries. Various lighting techniques were also implemented to see if there were other characters that could potentially be used to distinguish females and males. Measurements were not found to satisfactorily separate sexes; however, lateral lighting was found to consistently illuminate internal abdominal structures of S. comalensis where sternite 8 was viewable in males and the fused gonocoxites were viewable in females. Lateral lighting was used to examine living specimens of H. comalensis, and it was found that sternite 8 could be viewed in both sexes where the anterior strut of females was much longer and discernible from the anterior strut of males. Commentary regarding the use of cameras and photography for observing living subjects is given.


Assuntos
Besouros/anatomia & histologia , Abdome/anatomia & histologia , Animais , Espécies em Perigo de Extinção , Feminino , Masculino , Caracteres Sexuais
7.
Microsc Res Tech ; 82(8): 1372-1379, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31074937

RESUMO

Aphodiinae are a large cosmopolitan subfamily of Scarab beetles (Scarabaeoidea: Scarabaeidae), playing an important role during dung decomposition. Many aspects, especially immature stages, of these dung beetles have not yet been recorded due to their comparative small body sizes and lacking of striking rolling behavior. In this study, the third instar larva of Colobopterus quadratus is morphologically described using scanning electron microscopy. The larva is atypical for the combination of following morphological features: (a) the larval antennae are five-segmented; (b) the clypeus bears 4 minute protuberances on dorsal surface; (c) the epitorma on epipharynx is ventrally protuberant; (d) the scissorial area of left mandible is broad and blade-like; (e) the raster is furnished with six glabrous protuberances and two rows of pali arranged in V-shape. Some significant ultra-morphological features were discovered in larval Aphodiinae for the first time. The presence of blade-like incisor on the left mandible implies the potential root cutting ability.


Assuntos
Besouros/anatomia & histologia , Larva/anatomia & histologia , Animais , Antenas de Artrópodes/ultraestrutura , Tamanho Corporal , Incisivo/anatomia & histologia , Larva/ultraestrutura , Mandíbula/anatomia & histologia , Microscopia Eletrônica de Varredura , Pupa/anatomia & histologia
8.
Proc Biol Sci ; 286(1894): 20182175, 2019 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-30963875

RESUMO

The origin and early evolutionary history of polyphagan beetles have been largely based on evidence from the derived and diverse 'core Polyphaga', whereas little is known about the species-poor basal polyphagan lineages, which include Scirtoidea (Clambidae, Decliniidae, Eucinetidae, and Scirtidae) and Derodontidae. Here, we report two new species Acalyptomerus thayerae sp. nov. and Sphaerothorax uenoi sp. nov., both belonging to extant genera of Clambidae, from mid-Cretaceous Burmese amber. Acalyptomerus thayerae has a close affinity to A. herbertfranzi, a species currently occurring in Mesoamerica and northern South America. Sphaerothorax uenoi is closely related to extant species of Sphaerothorax, which are usually collected in forests of Nothofagus of Australia, Chile, and New Zealand. The discovery of two Cretaceous species from northern Myanmar indicates that both genera had lengthy evolutionary histories, originated at least by the earliest Cenomanian, and were probably more widespread than at present. Remarkable morphological similarities between fossil and living species suggest that both genera changed little over long periods of geological time. The long-term persistence of similar mesic microhabitats such as leaf litter may account for the 99 Myr morphological stasis in Acalyptomerus and Sphaerothorax. Additionally, the extinct staphylinoid family Ptismidae is proposed as a new synonym of Clambidae, and its only included species Ptisma zasukhae is placed as incertae sedis within Clambidae.


Assuntos
Distribuição Animal , Evolução Biológica , Besouros/anatomia & histologia , Fósseis/anatomia & histologia , Âmbar , Animais , Besouros/fisiologia , Masculino , Mianmar
9.
Proc Biol Sci ; 286(1896): 20182427, 2019 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-30963933

RESUMO

Understanding the origin of novel complex traits is among the most fundamental goals in evolutionary biology. The most widely used definition of novelty in evolution assumes the absence of homology, yet where homology ends and novelty begins is increasingly difficult to parse as evo devo continuously revises our understanding of what constitutes homology. Here, we executed a case study to explore the earliest stages of innovation by examining the tibial teeth of tunnelling dung beetles. Tibial teeth are a morphologically modest innovation, composed of relatively simple body wall projections and contained fully within the fore tibia, a leg segment whose own homology status is unambiguous. We first demonstrate that tibial teeth aid in multiple digging behaviours. We then show that the developmental evolution of tibial teeth was dominated by the redeployment of locally pre-existing gene networks. At the same time, we find that even at this very early stage of innovation, at least two genes that ancestrally function in embryonic patterning and thus entirely outside the spatial and temporal context of leg formation, have already become recruited to help shape the formation of tibial teeth. Our results suggest a testable model for how developmental evolution scaffolds innovation.


Assuntos
Evolução Biológica , Padronização Corporal/genética , Besouros/anatomia & histologia , Besouros/genética , Regulação da Expressão Gênica no Desenvolvimento , Redes Reguladoras de Genes , Animais , Besouros/embriologia , Extremidades/anatomia & histologia , Extremidades/embriologia , Feminino
10.
Nat Commun ; 10(1): 1312, 2019 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-30899023

RESUMO

Male genitalia exhibit patterns of divergent evolution driven by sexual selection. In contrast, for many taxonomic groups, female genitalia are relatively uniform and their patterns of evolution remain largely unexplored. Here we quantify variation in the shape of female genitalia across onthophagine dung beetles, and use new comparative methods to contrast their rates of divergence with those of male genitalia. As expected, male genital shape has diverged more rapidly than a naturally selected trait, the foretibia. Remarkably, female genital shape has diverged nearly three times as fast as male genital shape. Our results dispel the notion that female genitalia do not show the same patterns of divergent evolution as male genitalia, and suggest that female genitalia are under sexual selection through their role in female choice.


Assuntos
Evolução Biológica , Besouros/anatomia & histologia , Genitália Feminina/anatomia & histologia , Genitália Masculina/anatomia & histologia , Animais , Besouros/classificação , Besouros/genética , Feminino , Genitália Feminina/fisiologia , Genitália Masculina/fisiologia , Masculino , Preferência de Acasalamento Animal/fisiologia , Fenótipo , Filogenia , Reprodução , Seleção Genética , Fatores Sexuais
11.
Arthropod Struct Dev ; 50: 24-42, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30894327

RESUMO

Bombardier beetles are famous for their unique ability to explosively discharge hot quinones from their pygidial glands when threatened. Here we provide the first detailed description of the ultrastructure of the defensive gland system of the genus Paussus, the most speciose genus in the ground beetle subfamily Paussinae. Paussine beetles are commonly known as "flanged bombardier beetles" due to the presence of a flange on their elytra that assists in directing their defensive chemicals toward the front of their bodies. In this paper, we use optical, fluorescence and focused ion beam (FIB/SEM) microscopy to analyse and illustrate anatomy and ultrastructure of the explosive defensive system of Paussus favieri, a charismatic myrmecophilous species. The defensive system of this species consists of two independent, symmetrical glands each composed of secretory lobes, a long collecting duct, a bilobed reservoir chamber, a cuticular valve, a sclerotized reaction chamber, and an accessory chamber, associated with the reaction chamber, that is surrounded by several isolated glandular cells. Differences between the pygidial defensive systems of Paussus favieri and those of Brachininae are discussed.


Assuntos
Besouros/anatomia & histologia , Animais , Formigas , Besouros/ultraestrutura , Glândulas Exócrinas/anatomia & histologia , Glândulas Exócrinas/ultraestrutura , Feminino , Cadeia Alimentar , Masculino , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência
12.
Arthropod Struct Dev ; 49: 19-25, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30703537

RESUMO

The pygidial gland system is a key innovation in adephagan beetles, producing, storing, and spraying defensive chemical compounds. As the source of defensive chemical production and storage, the pygidial gland system experiences severe chemical stress which challenges the integrity of the entire gland system. Here, we utilize autofluorescence-based confocal laser scanning microscopy to examine the morphology of pygidial gland secretory lobes and collecting ductules in a common Pennsylvanian harpaline species, Harpalus pensylvanicus. The glandular units are composed of type-III exocrine cells which empty into resilin-rich ductules, which themselves lead into a larger resilin-rich collecting duct, and ultimately the pygidial reservoir pump. We also utilize histological staining with toluidine blue and brightfield imaging to provide additional support for the presence of resilin in the collecting duct, as toluidine blue has been shown to stain resilin without metachromasia. We hypothesize that the high resilin content of the collecting ducts might be a widespread key evolutionary adaptation to prevent damage caused by physical and chemical stress generated in pump-containing insect exocrine gland systems.


Assuntos
Besouros/anatomia & histologia , Proteínas de Insetos/análise , Animais , Glândulas Exócrinas/anatomia & histologia , Microscopia Confocal
13.
Arthropod Struct Dev ; 49: 10-18, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30721756

RESUMO

In the animal kingdom, macroscopic variations in size, color, and even hairiness are frequently observed between male and female, making the sex of various species easy to discern. In the case of insects, similar variances also exist. While direct observation is a quick and efficient way to differentiate between sexes, there are also variations which are unseen to the naked eye and occur on a micro- or nanoscopic scale. Sometimes, these micro/nanoscopic variations can lead to significant variations in surface properties as a function of sex. Such is the case for the Mecynorhina polyphemus confluens (Kraatz, 1890). In this work, we characterize these micro- and nanoscale differences, and describe their impact on the surface properties (e.g. wettability). It is found that water interacts quite differently with the surface of the cuticle of Mecynorhina polyphenus confluens, depending on the specimen sex. On a female, water spreads readily across the elytra indicating hydrophilic behavior. However, on the surface of the male elytra, strong hydrophobicity is observed. Microscopic observations reveal differences in microscale surface morphology across the male and female cuticle. These observations contribute to a better, global understanding of the wettability behavior observed on M. polyphemus confluens.


Assuntos
Besouros/anatomia & histologia , Besouros/química , Animais , Besouros/ultraestrutura , Feminino , Masculino , Microscopia Eletrônica de Varredura , Caracteres Sexuais , Propriedades de Superfície , Molhabilidade
14.
Arthropod Struct Dev ; 49: 1-9, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30710632

RESUMO

We investigated morphometric variation in size and shape of the head, pronotum, and abdomen between the taxa and sexes of two ground beetles, Carabus coriaceus cerisyi Dejean, 1826 and C. kollari praecellens Palliardi, 1825. These two taxa differ in overall size, and both of them are characterized by significant sexual size dimorphism. In many taxa, allometry, the relationship between changes in shape and changes in size, can be a major component of intra- and interspecific variation in body shape. In the present study, we applied landmark-based geometric morphometrics to explore allometric and non-allometric components of shape variation between the taxa and more importantly between sexes within the taxa. We were able to show that the differences of shape between the taxa cannot be explained by allometric changes, as allometry explains only a small amount of total shape variation between the taxa, which was expected due to the fact that the taxa belong to separate subgenera. Between the sexes, on the other hand, allometry contributes largely to the variation, particularly in abdomen shape. However, the differences of head and pronotum shape between the sexes cannot be entirely explained in terms of allometric scaling. Our results indicate that allometry contributes largely to differences of body shape between the sexes, while differences between the taxa are influenced by other factors and processes.


Assuntos
Besouros/anatomia & histologia , Animais , Tamanho Corporal , Feminino , Masculino , Caracteres Sexuais
15.
J Insect Sci ; 19(1)2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30794729

RESUMO

The objective of this study was to determine the number of instars of Monochamus alternatus Hope (Coleoptera: Cerambycidae) larvae by comparing their head capsule widths (HCW) published in previous studies, as well as additional laboratory experiments. Larvae of M. alternatus showed repeated molting in the laboratory. Most larvae ceased their development at the 10th instar stage. Frequency distributions of HCW for the first, second, and third instar larvae were clearly separated while those of the fourth through 11th instar larvae largely overlapped between successive instars in our results. The HCW values for the first, second, and third instar larvae directly measured for each instar in our study indicated that they were more precise than those of previous reports based on field-collected HCW which might have missed HCW of the first instar larvae or wrongly determined HCW for some instars. Unlike the reports of four instars of previous studies, M. alternatus larvae passed five instars in the field, which was confirmed by the discovery of five pairs of mandibles in the feeding gallery and pupal chamber. Also, the comparative study for the frequency distributions of HCW revealed that most M. alternatus larvae passed five instars. Consequently, the average sizes of HCW for their first, second, and third instar larvae are newly suggested to be 0.896 ± 0.069, 1.291 ± 0.131, and 1.707 ± 0.165 mm (mean ± SD) .


Assuntos
Besouros/anatomia & histologia , Larva/crescimento & desenvolvimento , Animais , Besouros/crescimento & desenvolvimento , Larva/anatomia & histologia
16.
PLoS One ; 14(1): e0209790, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30650132

RESUMO

The carabid subfamily Paussinae contains many species known to be obligately associated with ants during at least one stage of their life history. Myrmecophilous larvae have been documented for members of the tribe Paussini as well as several genera in the tribes Ozaenini, including Physea and Eustra. Here we describe the first instar larva of Ozaena lemoulti, and find it to be the most highly modified ozaenine larva that we have examined to date. Many structures of the larva suggest that it is a myrmecophile. Unlike all other described ozaenine larvae, which live in burrows that they construct and seal with their terminal disk, the completely unique larval morphology suggests Ozaena has adapted to living without the protection of a burrow and therefore must have a completely different feeding strategy than the typical ambush strategy of burrow dwelling larvae. We hypothesize that Ozaena larvae live in association with ants and use their long legs for running within the nest, and modifications of the mouthparts suggest the larva feeds on soft lightly sclerotized prey, such as ant brood. Our findings support an earlier hypothesis that Ozaena is mymecophilous during the adult stage. Comparisons of the functional anatomy of the eggs, larvae and adult between Ozaena lemoulti and the closely related, non-myrmecophilous general arthropod predator, Goniotropis kuntzeni, provide complementary, yet independent, evidence suggestive of this shift in lifestyle. We also examine and molecularly identify gut contents, providing direct evidence that adult Ozaena exclusively eat Camponotus ants. We conclude that Ozaena represents an independent shift to adopting a life of myrmecophily among beetles classified within the carabid subfamily Paussinae and document the morphological changes at each life history stage associated with the shift to a nest parasite lifestyle.


Assuntos
Formigas/parasitologia , Besouros/anatomia & histologia , Animais , Artrópodes , Larva/anatomia & histologia , Filogenia
17.
Arthropod Struct Dev ; 48: 56-70, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30630116

RESUMO

The wings of Ptiliidae, the coleopteran family containing the smallest free-living insects, are analyzed in detail for the first time. A reconstruction of the evolutionary sequence of changes associated with miniaturization is proposed. The wings of several species are described using light microscopy and scanning electron microscopy. The morphology and scaling are analyzed in comparison with larger representatives of related groups. The wings of all studied ptiliids show some degree of ptiloptery (feather-like shape, typical for extremely small insects). In larger ptiliids the wing contains at least five veins, has a wide blade, and bears a marginal fringe of 200-300 setae; in the smallest species it has three veins or fewer, a narrow blade, and about 40 setae along the margin. The setae are brush-like; peculiar outgrowths, denser towards the apex, increase the effective diameter of the setae. Morphometric analysis shows that the geometry of the wings and their elements strongly differs from those of other staphyliniform beetles, suggesting that the aerodynamics of the feather-like wings may also differ distinctly from the usual pattern.


Assuntos
Evolução Biológica , Besouros/anatomia & histologia , Asas de Animais/anatomia & histologia , Animais , Tamanho Corporal , Besouros/ultraestrutura , Microscopia Eletrônica de Varredura , Asas de Animais/ultraestrutura
18.
Micron ; 119: 24-38, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30660089

RESUMO

Bombardier beetles, belonging to the carabid subfamilies Paussinae and Brachininae, are famous for their unique ability to explosively discharge a hot spray of quinones from their pygidial glands when threatened. The paussine tribe Metriini is broadly acknowledged as the most basal group of bombardiers. In order to complement the available information on the chemical substances and the primitive discharging mechanism of Metriini, we provide a detailed morpho-functional analysis of the explosive defensive system of Metrius contractus Eschscholtz, 1829 and Sinometrius turnai Wrase and J. Schmidt, 2006, representatives of the two genera in this tribe. We use dissections, histology, scanning electron microscopy (SEM), and focused ion beam microscopy (FIB/SEM) to describe and illustrate various levels of anatomical complexity. FIB/SEM microscopy is used to analyse ultrastructural features of the cellular regions, replacing the classical transmission electron microscopy (TEM). Compared to other Paussinae tribes, Metriini lacks the typical flange of Coanda, the elytral fold used to direct the defensive secretions forward, but has a similar arrangement of internal components. We find that the internal components of the explosive defensive system, including the secretory lobes, collecting duct, reservoir chamber, valve, reaction chamber, accessory chamber and accessory glands, are only slightly different between Metrius Eschscholtz, 1829 and Sinometrius Wrase and J. Schmidt, 2006. The accessory chamber to the reaction chamber is a unique, derived character state common to all Paussinae examined and therefore represents a clear apomorphy of the Paussinae. We use the same microscopy techniques as used in a recent publication on the Brachininae, to compare the defensive systems of Metriini and Brachininae. We find a lack of morphological similarity at the ultrastructural level, suggesting that the bombarding mechanism may have evolved independently in the Paussinae and the Brachininae, perhaps in response to different ecological pressures.


Assuntos
Besouros/anatomia & histologia , Besouros/ultraestrutura , Microscopia , Animais , Técnicas Histológicas
19.
Dev Growth Differ ; 61(1): 73-84, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30644547

RESUMO

Many organisms show various geometric color patterns on their bodies, and the developmental, evolutionary, genetic, and ecological bases of these patterns have been intensely studied in various organisms. Ladybird beetles display highly diverse patterns of wing (elytral) color and are one of the most attractive model organisms for studying these characteristics. In this study, we reviewed the genetic history of elytral color patterns in the Asian multicolored ladybird beetle Harmonia axyridis from the classical genetic studies led by the pupils of Thomas Hunt Morgan and Theodosius Dobzhansky to recent genomic studies that revealed that a single GATA transcription factor gene, pannier, regulates the highly diverse elytral color patterns in this species. We also reviewed and discussed the developmental and evolutionary mechanisms driven by the pannier locus in H. axyridis. In the development sections, we focused on the following two topics: (a) how the red (carotenoid) and black (melanin) pigmentation of elytra is regulated by the pannier and pigmentation genes and (b) how the diverse color patterns are formed by integrating regulatory inputs from other genes involved in wing development. In the evolution section, we subsequently focused on the highly diversified DNA sequences within the first intron of pannier that are 56-76 kb long and that were generated through recurrent multiple inversions. Furthermore, we discussed how these recurrent inversions have driven the diversification of color patterns throughout evolution.


Assuntos
Evolução Biológica , Besouros/anatomia & histologia , Besouros/genética , Pigmentação/genética , Animais , Sequência de Bases
20.
Arthropod Struct Dev ; 48: 71-82, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30639185

RESUMO

Pterothoracic structures of the minute ptiliid Nephanes titan were examined and described in detail. Effects of miniaturization and the phylogenetic and functional background are discussed. Apomorphies shared with Hydraenidae are the large metascutal shield, the fringe of setae along the posterior edge of the wings, and the fusion of the mesoventrite with the mesanepisternum. Autapomorphies of Ptiliidae are the highly modified feather-like wings, the strongly elongated alacristae, the loss of the mesotrochantin, the enlarged metathoracic pleural wing joint, and the simplification of the direct flight musculature. Most phylogenetically relevant features are linked with miniaturization, especially the modifications of the wings and skeleton, for instance the reduced wing membrane or the simplified metanotum without distinct notal wing processes. Ptiliids show flight characteristics that distinctly differ from what is known in other insects, such as an unusually high amplitude of beats of the elytra, and a unique trajectory of wing return movements, as well as the presence of upper and lower claps. A comparison of cross-sections of ptiliid principal flight muscles with those of larger staphyliniform beetles suggests that muscles of the tiniest beetles are relatively smaller. This may reflect the higher aerodynamic efficiency of ptiliid feather wings compared to the common membranous wings found in other groups.


Assuntos
Besouros/anatomia & histologia , Asas de Animais/anatomia & histologia , Animais , Tamanho Corporal , Besouros/fisiologia , Extremidades/anatomia & histologia , Voo Animal
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