RESUMO
The sperm morphology of two predatory bugs Amphiareus constrictus and Blaptostethus pallescens, representing the tribes Dufouriellini and Blasptostethini, respectively, was described using light and transmission electron microscopy. The spermatozoa of Amphiareus constrictus and Blaptostethus pallescens are fine and long, each measuring 216.6µm and 181.0µm in length, of which 37.0µm and 11.6µm, respectively, comprise the nuclei. When stained with DAPI (for DNA), the posterior half of the nucleus in B. pallescens exhibited low fluorescence, while in A. constrictus this feature was observed only in the last 6µm. In both species, as in Heteroptera in general, the spermatozoa have, in the head region, an acrosome and nucleus, and in the flagellar region, an axoneme with 9 accessory tubules, 9 peripheral doublets and 2 central microtubules (9+9+2 microtubules), 2 mitochondrial derivatives (MDs), and a centriolar adjunct in the nucleus-flagellum transition. However, unlike most Heteroptera, in these species, the MDs are asymmetric, and the centriolar adjunct is quite long and encompasses completely the posterior nuclear end and the anterior tips of the MDs. These features are considered as derived, thus supporting the condition derived of Anthocoridae within Cimicomorpha. In addition, several traits of the spermatozoa of these two species easily distinguish one species (and probably a tribe) from the other; for example, the difference of formats in the MDs, and the long anterior projection of the centriolar adjunct parallel to the nucleus in B. pallescens.
Assuntos
Heterópteros/anatomia & histologia , Heterópteros/ultraestrutura , Cabeça do Espermatozoide/ultraestrutura , Animais , Núcleo Celular/ultraestrutura , Centríolos/ultraestrutura , Masculino , Microscopia Eletrônica de Transmissão , Mitocôndrias/fisiologiaRESUMO
The exceptional abilities of stink bugs (Hemiptera: Pentatomidae) to colonize a diverse group of plants have been attributed to the feeding behaviors and the functions of the salivary complex of these insects. Here, we describe the ultrastructure of the salivary glands of the Neotropical brown stink bug, Euschistus heros, which is a major component of the pentatomid pest complex on soybeans, Glycine max, in the neotropics. Our results revealed a salivary gland complex consisting of two lobes (i.e., anterior and posterior), with a constriction between them (i.e., the hilum), in which the salivary and accessory gland ducts are inserted. The principal gland epithelium has a single layer of cells lining an enlarged lumen filled with saliva, and these cells are cuboidal, rich in rough endoplasmic reticulum and secretory vesicles, with well-developed nuclei, all of which are typical features of protein-secreting cells. We report, for the first time in insects, the presence of a layer of muscle cells surrounding the columnar hilum epithelium. The accessory salivary gland cells are cuboidal with nuclei containing condensed chromatin and cytoplasm rich in vacuoles and rough endoplasmic reticulum, indicating the potential involvement of these glands in water transport/secretion. The lumen content of each lobe of the principal gland suggests that the lobes produce different compounds. Thus, our results suggest that the E. heros salivary complex might have unconventional mechanisms to mix/release saliva, which might help explain the polyphagous abilities of these insects.
Assuntos
Retículo Endoplasmático Rugoso/ultraestrutura , Heterópteros/ultraestrutura , Células Musculares/ultraestrutura , Glândulas Salivares/ultraestrutura , Vacúolos/ultraestrutura , Animais , Comportamento AlimentarRESUMO
The testicular, spermatogenesis and sperm morphology of the backswimmer Martarega bentoi was described using light and transmission electron microscopy. In this species, a pair of testes, two deferent ducts, two different pairs of accessory glands, and an ejaculatory duct form the male reproductive system. Each testis consists of two testicular follicles, which are arranged side by side in snail shape. The follicles are filled with cysts at different stages of spermatogenesis, but in the same cyst the germ cells (up to 64) are in the same stage. At the end of spermatogenesis, the sperm cells are very long, with the flagellum measuring approximately 2500 µm in length, the nucleus only 19 µm, and the acrosome, with two distinct regions, 300 µm. The flagellum is composed of an axoneme, with a 9 + 9 + 2 microtubular pattern, and 2 asymmetric mitochondrial derivatives (MDs). These have the anterior ends inserted into two cavities at the nucleus base, exhibit two paracrystalline inclusions, and have bridges linking them to the axoneme. Few spermatozoa per cyst, asymmetry in size and shape of the MDs, as well as their insertion at the nuclear base are characteristics considered derived, and that differentiate the sperm of M. bentoi from those of the Nepomorpha, Belostomatidae and Nepidae.
Assuntos
Heterópteros/ultraestrutura , Espermatogênese , Testículo/ultraestrutura , Acrossomo/ultraestrutura , Animais , Heterópteros/anatomia & histologia , Masculino , Microscopia Eletrônica de Transmissão , Espermatozoides/ultraestrutura , Testículo/anatomia & histologiaRESUMO
Heteroptera have diverse feeding habits with phytophagous, zoophagous, and haematophagous species. This dietary diversity associated with the monophyly of Heteroptera makes these insects a good object for comparative studies of the digestive tract. This work compares the ultrastructure of the middle midgut region in the phytophagous Coptosoma scutellatum (Plataspidae), Graphosoma lineatum (Pentatomidae), Kleidocerys resedae (Lygaeidae), and zoophagous Rhynocoris iracundus (Reduviidae), Nabis rugosus (Nabidae), and Himacerus apterus (Nabidae), to verify if diet affects midgut cells in phylogenetically related insects. The middle region of the midgut was used for comparison because it is the main site for digestion and absorption of the midgut. The digestive cell ultrastructure was similar in the six species, with features of secretory, absorptive, transport, storage, and excretory cells, suggesting a stronger correlation of middle digestive cell ultrastructure with the phylogeny of these species than with the different heteropteran feeding habits.
Assuntos
Trato Gastrointestinal/ultraestrutura , Heterópteros/ultraestrutura , Animais , Carnivoridade , Trato Gastrointestinal/fisiologia , Herbivoria , RegeneraçãoRESUMO
Stenogeocoris Montandon, 1913 fue descripto para incluir a S. horvathi basado en un espécimen de Córdoba, Argentina. El ejemplar tipo está perdido y no hay registros o material adicional desde la descripción de Montandon. Por lo tanto, la identidad de este taxón ha permanecido incierta hasta ahora. En esta contribución, se redescribe el género Stenogeocoris y la especie S. horvathi, basado en especímenes macho y hembra e incluyendo caracteres de la genitalia del macho. Además se compara Stenogeocoris con los otros géneros neotropicales.(AU)
Stenogeocoris Montandon, 1913 was described to include S. horvathi based in one specimen from Córdoba Province, Argentina. The type specimen is lost and there are no records or additional material since the Montandon's description; thus, the identity of this taxon has remained uncertain until now. In this contribution, we redescribe the genus Stenogeocoris and the species S. horvathi, based on male and female specimens, including characters from the male genitalia, and compare Stenogeocoris with the other Neotropical genera(AU)
Assuntos
Animais , Heterópteros/anatomia & histologia , Heterópteros/classificação , Heterópteros/ultraestrutura , ArgentinaRESUMO
Stenogeocoris Montandon, 1913 fue descripto para incluir a S. horvathi basado en un espécimen de Córdoba, Argentina. El ejemplar tipo está perdido y no hay registros o material adicional desde la descripción de Montandon. Por lo tanto, la identidad de este taxón ha permanecido incierta hasta ahora. En esta contribución, se redescribe el género Stenogeocoris y la especie S. horvathi, basado en especímenes macho y hembra e incluyendo caracteres de la genitalia del macho. Además se compara Stenogeocoris con los otros géneros neotropicales.
Stenogeocoris Montandon, 1913 was described to include S. horvathi based in one specimen from Córdoba Province, Argentina. The type specimen is lost and there are no records or additional material since the Montandon's description; thus, the identity of this taxon has remained uncertain until now. In this contribution, we redescribe the genus Stenogeocoris and the species S. horvathi, based on male and female specimens, including characters from the male genitalia, and compare Stenogeocoris with the other Neotropical genera
Assuntos
Animais , Heterópteros/anatomia & histologia , Heterópteros/classificação , Heterópteros/ultraestrutura , ArgentinaRESUMO
The genus Paracholula Harrington has been represented by two species, P. picta (Fab) and P. thoracica (Distant), both recorded from Mexico. Individuals of one population from Guerrero were studied and compared with individuals of both species from different collections, including the types. Using scanning electron micrographs of different structures, and observation of the male genitalia of some individuals, together with a close examination of all the individuals from the population from Guerrero, we discovered, that there is great variation in all the structures and that some characters that were used to separate the two species are present within the population from Guerrero. Therefore we synonymize both species, stating that the valid name for this species is Paracholula picta (Fab). Descriptions and illustrations of all the immature stages from the Guerrero population are included. Notes about host plants, biology and distributional records are also included.
Assuntos
Heterópteros/anatomia & histologia , Heterópteros/classificação , Animais , Ecossistema , Feminino , Heterópteros/fisiologia , Heterópteros/ultraestrutura , Masculino , México , Microscopia Eletrônica de Varredura , Ninfa/anatomia & histologia , Ninfa/classificação , Ninfa/fisiologia , Ninfa/ultraestruturaRESUMO
Cell death, proliferation, and differentiation in some developmental stages of insects have been studied in the midgut of ametabolous, which undergo only continuous growth, and holometabolous, which undergo complete metamorphosis. However, in hemimetabolous insects, evolutionarily intermediate between ametabolous and holometabolous, midgut reorganization during the post-embryonic development has been poorly studied. The present study evaluates the post-embryonic development of the midgut of a hemimetabolous insect, Podisus nigrispinus, to test the hypothesis that these insects have programmed cell death and proliferation followed by differentiation of regenerative cells during midgut growth from nymphs to adult. The morphometrical data showed a 6-fold increase in midgut length from the first instar nymph to the adult, which did not result from an increase in the size of the midgut cells, suggesting that the growth of the midgut occurs by an increase in cell number. Cell death was rarely found in the midgut, whereas proliferation of regenerative cells occurred quite frequently. The growth of the midgut of P. nigrispinus appears to result from the proliferation of regenerative cells present in the epithelium; unlike ametabolous and holometabolous insects, the midgut of P. nigrispinus does not undergo extensive remodeling, as shown by the low frequency of digestive cell death.
Assuntos
Heterópteros/crescimento & desenvolvimento , Heterópteros/ultraestrutura , Animais , Apoptose , Diferenciação Celular , Proliferação de Células , Sistema Digestório/crescimento & desenvolvimento , Sistema Digestório/fisiopatologia , Sistema Digestório/ultraestrutura , Heterópteros/fisiologia , Metamorfose Biológica , Microscopia Eletrônica de Transmissão , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Ninfa/ultraestruturaRESUMO
The predatory stinkbug Podisus nigrispinus has been utilized in biological control programs. Its midgut is anatomically divided into anterior, middle and posterior regions, which play different roles in the digestive process. We describe the midgut ultrastructure and the secretion of digestive enzymes in the midgut of P. nigrispinus. Midguts were analyzed with transmission electron microscopy and the digestive enzymes amylase, cathepsin L, aminopeptidase and α-glucosidase were immunolocalized. The ultrastructural features of the digestive cells in the anterior, middle and posterior midgut regions suggest that they play a role in digestive enzyme synthesis, ion and nutrient absorption, storage and excretion. The digestive enzymes have different distribution along the midgut regions of the predator P. nigrispinus. Amylase, aminopeptidase and α-glucosidase occur in three midgut regions, whereas cathepsin L occurs in the middle and posterior midgut regions. The anterior midgut region of P. nigrispinus seems to play a role in water absorption, the middle midgut may be involved in nutrient absorption and the posterior midgut region is responsible for water transport to the midgut lumen.
Assuntos
Heterópteros/ultraestrutura , Hidrolases/metabolismo , Animais , Western Blotting , Brasil , Sistema Digestório/enzimologia , Sistema Digestório/ultraestrutura , Eletroforese em Gel de Poliacrilamida , Heterópteros/enzimologia , Masculino , Microscopia Eletrônica de TransmissãoRESUMO
Pre-oral digestion is described as the liquefaction of the solid tissues of the prey by secretions of the predator. It is uncertain if pre-oral digestion means pre-oral dispersion of food or true digestion in the sense of the stepwise bond breaking of food polymers to release monomers to be absorbed. Collagenase is the only salivary proteinase, which activity is significant (10%) in relation to Podisus nigrispinus midgut activities. This suggests that pre-oral digestion in P. nigrispinus consists in prey tissue dispersion. This was confirmed by the finding of prey muscles fibers inside P. nigrispinus midguts. Soluble midgut hydrolases from P. nigrispinus were partially purified by ion-exchange chromatography, followed by gel filtration. Two cathepsin L-like proteinases (CAL1 and CAL2) were isolated with the properties: CAL1 (14.7 kDa, pH optimum (pHo) 5.5, km with carbobenzoxy-Phe-Arg-methylcoumarin, Z-FR-MCA, 32 µM); CAL2 (17 kDa, pHo 5.5, km 11 µM Z-FR-MCA). Only a single molecular species was found for the other enzymes with the following properties are: amylase (43 kDa, pHo 5.5, km 0.1% starch), aminopeptidase (125 kDa, pHo 5.5, km 0.11 mM l-Leucine-p-nitroanilide), α-glucosidase (90 kDa, pHo 5.0, km 5mM with p-nitrophenyl α-d-glucoside). CAL molecular masses are probably underestimated due to interaction with the column. Taking into account the distribution of hydrolases along P. nigrispinus midguts, carbohydrate digestion takes place mainly at the anterior midgut, whereas protein digestion occurs mostly in middle and posterior midgut, as previously described in seed- sucker and blood-feeder hemipterans.
Assuntos
Heterópteros/metabolismo , Animais , Heterópteros/enzimologia , Heterópteros/ultraestrutura , Concentração de Íons de Hidrogênio , Hidrolases/isolamento & purificação , Hidrolases/metabolismo , Masculino , Microscopia Eletrônica de Transmissão , Glândulas Salivares/enzimologia , Glândulas Salivares/metabolismo , Proteínas e Peptídeos Salivares/metabolismoRESUMO
Pentatomidae is one of the largest Heteroptera families, comprising about 10% of the species estimated for the suborder. In spite of existing studies, doubts remain regarding the systematics of Pentatomomorpha. In this study, five species of Pentatomidae spermatozoa were examined to achieve characteristics that enable inferences in the phylogeny of the group and in behavioral issues associated with the presence of polymorphisms. Spermatozoa polymorphisms, characterized by two classes of sizes, are found in Podisus nigrispinus, Podisus distinctus, and Brontocoris tabidus, whereas Thynacanta marginata (Dallas) and Supputius cincticeps have single-size spermatozoa. The head region consists of an acrosome, a nucleus, and part of the centriolar adjunct. In the more anterior region, the nucleus is parallel to the centriolar adjunct. In the nucleus-flagellum transition region, the nucleus overlaps the anterior region of the mitochondrial derivatives, just above the axoneme. The mitochondrial derivatives and the axoneme run the entire extent of the flagellum. In species in which the spermatozoa are polymorphic, the larger spermatozoa have derivatives mitochondrial approximately 3-fold larger than the smaller spermatozoa. Characteristics derived from the morphology of spermatozoa indicate synapomorphies and are promising for systematic studies.
Assuntos
Heterópteros/ultraestrutura , Espermatozoides/ultraestrutura , Acrossomo/ultraestrutura , Animais , Axonema , Núcleo Celular/ultraestrutura , Centríolos/ultraestrutura , Flagelos/ultraestrutura , Heterópteros/genética , Masculino , Microscopia Eletrônica de Transmissão , Mitocôndrias/ultraestrutura , Filogenia , Espermatozoides/metabolismoRESUMO
The Berytidae or stilt bugs are a cosmopolitan family of lygaeoid bugs, which are slender, elongate insects, with generally cylindrical bodies and very long, slender antennae and legs. Members of the tribe Hoplinini are characterized by the lack of a distinct metapleural scent channel and the possession of a dorsally directed process on the caudal edge of the male genitalia capsule (absent in Xenoloma and Cuscohoplininus). In this paper, we described the new genus and species Cuscohoplininus pagoreni from Peru. Scanning electron micrographs are provided to illustrate taxonomically important structures. Among the eight genera known in the tribe Hoplinini, the new genus Cuscohoplininus resembles Parajalysus in general aspect and size, but can be easily distinguished by the following characters: Parajalysus is characterized by the four large, erect pronotal spines, one centered on the anterior lobe, and on the posterior lobe, one at each humeral angle and one at the base of the meson; whereas, Cuscohoplininus has a single spine on the anterior pronotal lobe, an elongate scutellar spine (a tubercle is present in Parajalysus), and lacks a process on the caudal edge of the male genitalia capsule. Rev. Biol. Trop. 55 (2): 673-676. Epub 2007 June, 29.
La familia Berytidae es cosmopolita y está integrada por chinches alargadas, con cuerpo generalmente cilíndrico y con antenas y patas muy largas. Los miembros de la tribu Hoplinini se caracterizan por carecer de canal la glándula repugnatoria y por poseer un proceso caudal dirigido dorsalmente sobre el borde posterior de la cápsula genital masculina (ausente en Xenoloma y Cuscohoplininus). Describimos un nuevo género y especie: Cuscohoplininus pagoreni de Perú. Se tomaron fotografías de microscopia electrónica para ilustrar estructuras de importancia taxonómica. Entre los ocho géneros conocidos de la tribu Hoplinini, Cuscohoplininus n. gen. es similar al género Parajalysus en aspecto general y en tamaño. Sin embargo, puede distinguirse así: Parajalysus se caracteriza por poseer cuatro grandes espinas erectas sobre el pronoto, una en el centro del lóbulo anterior, una en cada ángulo humeral y, la cuarta, también sobre el lóbulo posterior sobre el margen posterior; por otro lado Cuscohoplininus tiene una sola espina sobre el pronoto situada sobre el lóbulo anterior, una espina escutelar (Parajalysus presenta solo un tubérculo sobre el escutelo) y carece de proceso caudal.
Assuntos
Animais , Masculino , Heterópteros/classificação , Heterópteros/anatomia & histologia , Heterópteros/ultraestrutura , Microscopia Eletrônica , PeruRESUMO
The Berytidae or stilt bugs are a cosmopolitan family of lygaeoid bugs, which are slender, elongate insects, with generally cylindrical bodies and very long, slender antennae and legs. Members of the tribe Hoplinini are characterized by the lack of a distinct metapleural scent channel and the possession of a dorsally directed process on the caudal edge of the male genitalia capsule (absent in Xenoloma and Cuscohoplininus). In this paper, we described the new genus and species Cuscohoplininus pagoreni from Peru. Scanning electron micrographs are provided to illustrate taxonomically important structures. Among the eight genera known in the tribe Hoplinini, the new genus Cuscohoplininus resembles Parajalysus in general aspect and size, but can be easily distinguished by the following characters: Parajalysus is characterized by the four large, erect pronotal spines, one centered on the anterior lobe, and on the posterior lobe, one at each humeral angle and one at the base of the meson; whereas, Cuscohoplininus has a single spine on the anterior pronotal lobe, an elongate scutellar spine (a tubercle is present in Parajalysus), and lacks a process on the caudal edge of the male genitalia capsule.
Assuntos
Heterópteros/classificação , Animais , Heterópteros/anatomia & histologia , Heterópteros/ultraestrutura , Masculino , Microscopia Eletrônica , PeruRESUMO
Podisus nigrispinus (Dallas) is a common predator in agricultural and natural systems in Neotropical America. Its feeding strategy involves extra-oral digestion and to better understand this process its salivary glands were extracted and subjected to morphological and preliminary enzyme characterization. The salivary glands of P. nigrispinus are formed by a pair of main and accessory gland complexes. The main salivary glands are further divided into an anterior and a posterior lobe. The compartmentalization of the salivary gland complex is likely to be important for the production, activation and release of the digestive enzymes used in the extra-oral digestion of prey items. Proteases and lipase, important digestive enzymes involved in zoophagy, were detected in the salivary glands of P. nigrispinus. The prevailing trypsin-like protease activity was characterized by using the serine-protease substrate N-alpha-benzoyl-L-Arg-p-nitroanilidine (L-BApNA) and the trypsin inhibitors tosyl-L-lysine chloromethyl ketone (TLCK) and benzamidine. The KM value obtained for trypsin-like activity was 1.57 mm and the different peaks of optimum pH and temperature activity suggest the presence of multiple forms of this enzyme in P. nigrispinus. Detection of amylase activity in the salivary glands of this predator suggests its ability to digest starch and obtain nutrients from plants, which may have adaptative value under prey scarcity.
Assuntos
Heterópteros/enzimologia , Heterópteros/ultraestrutura , Amilases/análise , Amilases/metabolismo , Animais , Benzamidinas/farmacologia , Benzoilarginina Nitroanilida/metabolismo , Digestão/fisiologia , Feminino , Heterópteros/fisiologia , Concentração de Íons de Hidrogênio , Hidrólise , Lipase/análise , Lipase/metabolismo , Masculino , Microscopia Eletrônica de Varredura/veterinária , Glândulas Salivares/enzimologia , Glândulas Salivares/ultraestrutura , Serina Endopeptidases/análise , Serina Endopeptidases/efeitos dos fármacos , Serina Endopeptidases/metabolismo , Inibidores de Serina Proteinase/farmacologia , Temperatura , Tosilina Clorometil Cetona/farmacologiaRESUMO
Leptomonas wallacei is a monoxenic trypanosomatid that colonizes the digestive tract of the phytophagous hemipteran Oncopeltus fasciatus. This infection was specific and took place exclusively in midgut intestinal ventricles V3 and V4, and in the hindgut. Abundances of parasites in the hindgut were 54% less than those in the hindgut. Parasites in the hindgut were more slender and had a longer flagellum than those from the hindgut, which were rounded, with a shorter flagellum. Moreover, hindgut forms expressed sugar residues on the cell surface, recognized by the lectins from Griffonia simplicifolia-I (alpha-galactose, alpha-N-acetyl-galactosamine) and Helix pomatia (N-acetyl-galactosamine); those sugar residues were not present in protozoa from the midgut. In culture, parasites were morphologically similar to midgut forms, but differed from them because they did not express sugar residues that bind to lectin (beta-galactose(1-3) N-acetyl-galactosamine) from Arachis hypogaea.
Assuntos
Carboidratos/análise , Sistema Digestório/parasitologia , Heterópteros/parasitologia , Trypanosomatina/ultraestrutura , Animais , Sistema Digestório/ultraestrutura , Heterópteros/ultraestrutura , Microscopia Eletrônica de Varredura , Trypanosomatina/crescimento & desenvolvimento , Trypanosomatina/isolamento & purificaçãoRESUMO
Heteropteran chromosomes are holokinetic; during mitosis, sister chromatids segregate parallel to each other but, during meiosis, kinetic activity is restricted to one pair of telomeric regions. This meiotic behaviour has been corroborated for all rod bivalents. For ring bivalents, we have previously proposed that one of the two chiasmata releases first, and a telokinetic activity is also achieved. In the present work we analyse the meiotic behaviour of ring bivalents in Pachylis argentinus (Coreidae) and Nezara viridula (Pentatomidae) and we describe for the first time the chromosome complement and male meiosis of the former (2n = 12 + 2m + X0, pre-reduction of the X). Both species possess a large chromosome pair with a secondary constriction which is a nucleolus organizer region as revealed by in-situ hybridization. Here we propose a new mode of segregation for ring bivalents: when the chromosome pair bears a secondary constriction, it is not essential that one of the chiasmata releases first since these regions or repetitive DNA sequences adjacent to them become functional as alternative sites for microtubule attachment and they undertake chromosome segregation to the poles during anaphase I.