Aspectos biológicos e morfologia externa dos imaturos de Memphismoruus stheno (Prittwitz) (Lepidoptera: Nymphalidae) / Biological aspects and external morphology of immature stages of Memphis moruus stheno (Prittwittz) (Lepidoptera: Nymphalidae)

Immature stages of Memphis moruus stheno (Prittwittz) were subject of a behavior, biological and morphological study. The morphological study was carried out through observation by stereoscopic microscopy with camera lucida and micrometric lens attached for illustrations and measurements, respectively; and scanning electron microscopy for ultrastructural analysis. Behavioral data were obtained through direct observation in the field and laboratory. Eggs were laid on the underside of leaves of two Lauraceae species. The first to third instars build frass chains, the fourth and the fifth instars build a conical shelter using a single leaf of the host plant. Before pupation, larvae bend its body ventrally and the pupae are incapable of movement. Descriptions, illustrations and photographs of egg, all five instars and pupa are given. The cephalic morphology and chaetotaxy of first instar were described and illustrated. Results are compared with other Charaxinae immature stages.

Mitochondria in the midgut epithelial cells of sugarcane borer parasitized by Cotesia flavipes (Cameron, 1891) / Mitocôndria nas Células Epiteliais do Intestino Médio da Broca-da-cana Parasitada por Cotesia flavipes

The sugarcane borer Diatraea saccharalis (Lepidoptera: Crambidae) has been controlled by Cotesia flavipes (Hymenoptera: Braconidae); however, very little is known about the effect of the parasitism in the host organs, including the midgut. This work aims to verify mitochondrial alteration in the different midgut epithelial cells of D. saccharalis parasitized by C. flavipes. Midgut fragments (anterior and posterior region) of both non-parasitized and parasitized larvae were processed for transmission electron microscopy. The mitochondria of midgut epithelial cell in the parasitized larvae exhibit morphological alteration, represented by matrix rarefaction and vacuolisation. These mitochondrial alterations are more pronounced in the anterior midgut region during the parasitism process, mainly in the columnar cell.

Diatraea saccharalis (Lepidoptera: Crambidae), broca da cana-de-açúcar, tem sido controlada por Cotesia flavipes (Hymenoptera: Braconidae); pouco se sabe sobre o efeito do parasitismo nos diferentes órgãos do inseto hospedeiro, principalmente no intestino médio. O objetivo desse trabalho foi verificar as alterações mitocondriais das diferentes células epiteliais do intestino médio de larvas de D. saccharalis parasitadas por C. flavipes. Fragmentos do intestino médio (regiões anterior e posterior) de larvas de D. saccharalis não-parasitadas e parasitadas foram processados para microscopia eletrônica de transmissão. As mitocôndrias das células epiteliais do intestino médio de larvas parasitadas exibem alterações, especialmente rarefação e vacuolização da matriz, que foram mais pronunciadas nas células epiteliais da região anterior do intestino médio na vigência do parasitismo, em especial nas células colunares.

Histochemical and ultrastructural evidence of lipid secretion by the silk gland of the sugarcane borer Diatraea saccharalis (Fabricius) (Lepidoptera: Crambidae)

The silk gland in Lepidoptera larvae is responsible for the silk production used for shelter or cocoon construction. The secretion of fibroin and sericin by the different silk gland regions are well established. There are few attempts to detect lipid components in the insect silk secretion, although the presence of such element may contribute to the resistance of the shelter to wet environment. This study characterizes the glandular region and detects the presence of lipid components in the secretion of the silk gland of Diatraea saccharalis(Fabricius). The silk gland was submitted to histochemical procedure for lipid detection or conventionally prepared for ultrastructural analyses. Lipid droplets were histochemically detected in both the apical cytoplasm of cell of the anterior region and in the lumen among the microvilli. Ultrastructural analyses of the anterior region showed lipid material, visualized as myelin-like structures within the vesicular Golgi complex and in the apical secretory globules, mixed up with the sericin; similar material was observed into the lumen, adjacent to the microvilli. Lipids were not detected in the cells neither in the lumen of the posterior region. Our results suggest that the silk produced by D. saccharalis has a minor lipid content that is secreted by the anterior region together with the sericin.

A glândula da seda de larvas de Lepidoptera é responsável pela produção da seda usada na construção do casulo ou do abrigo. A secreção de fibroína e sericina pelas diferentes regiões da glândula da seda está bem estabelecida. Existem poucos trabalhos tentando identificar componentes lipídicos na secreção de seda de insetos, embora a presença desse componente contribua para a resistência da seda a ambiente úmidos. Este estudo teve como objetivo identificar a presença de componente lipídico na secreção da glândula da seda de larvas de Diatraea saccharalis (Fabricius), bem como caracterizar a região glandular responsável pela secreção. A glândula da seda foi submetida a procedimentos histoquímicos para detecção de lipídeos e convencionalmente preparada para análise ultra-estrutural. Gotas lipídicas foram histoquimicamente detectadas no citoplasma apical de células da região anterior e no lúmen, entre os microvilos. A análise ultra-estrutural da região anterior mostrou material lipídico, visualizado como figuras do tipo mielina dentro do complexo de Golgi vesicular e nos glóbulos secretores apicais, misturados com sericina; material semelhante foi observado dentro do lúmen, adjacente aos microvilos. Nenhum componente secretor lipídico foi detectado nas células ou no lúmen da região posterior. Os resultados sugerem que a seda produzida pela D. saccharalis tem, pelo menos, um discreto componente lipídico, que é secretado pela região anterior, junto com a sericina.

Morphological aspects of cluster formation in the germarium of the sugarcane borer Diatraea saccharalis Fabricius (Lepidoptera: Pyralidae)

Diatraea saccharalis F. is one of the greatest pests of the sugar cane culture. This report aimed to characterize the germarium region of the sugarcane borer by light and transmission electron microscopy, emphasizing the morphological steps of the ovarian cluster formation. In the germarium of this insect, four zones could be morphologically identified during the cluster formation. In the most apical end of each ovariole - Zone I - the germ line stem cells undergo complete mitotic division, originating the cystoblasts. In the Zone II, each cystoblast produces a group of eight cells, the cystocytes, which are interconnected by the ring canals. Clusters containing all the cystocytes in the meiosis, characterizes the Zone III. Germ cells with ultrastructural features of apoptosis are also detected in this Zone. In the Zone IV the cystocytes differentiate, morphologically, into one oocyte and seven nurse cells. Interstitial somatic cells and pre-follicle cells exhibit, in their cytoplasm, heterogeneous vacuoles containing degenerated cellular fragments, characterized as apoptotic bodies. Our results pointed out to the morphological evidences related with important control mechanisms for new clusters/follicles production and for the cellular arrangement into the germarium, resulting from the programmed cell death. We believe that the morphological characterization of ovarian cluster formation in D. saccharalis provided valuable information for the understanding of the initial steps of oogenesis and contributed for the knowledge of the cellular mechanisms related with the oocyte production and with reproduction in insects.

Diatraea saccharalis Fabricius é uma das maiores pragas da cultura da cana-de-açúcar. Este trabalho visou caracterizar a região do germário da broca da cana pela microscopia de luz e eletrônica de transmissão, enfatizando as etapas morfológicas da formação do cisto ovariano. No germário desse inseto, quatro zonas puderam ser identificadas morfologicamente durante a formação do cisto. Na extremidade apical de cada ovaríolo - Zona I - as células germinativas primordiais sofrem divisão mitótica completa, originando os cistoblastos. Na Zona II, cada cistoblasto produz um grupo de oito células, os cistócitos, os quais são interconectados por canais circulares. Grupos contendo cistócitos na meiose caracterizam a Zona III. Células germinativas com características ultraestruturais de apoptose são também detectadas nesta zona. Na Zona IV os cistócitos se diferenciam, morfologicamente, em um oócito e sete células nutridoras. As células somáticas intersticiais e células pré-foliculares exibem em seus citoplasmas vacúolos heterogêneos contendo fragmentos celulares degenerados, caracterizados como corpos apoptóticos. Os resultados apontam evidências morfológicas relacionadas com importantes mecanismos de controle para a produção de novos cistos/folículos e para o rearranjo celular no germário, resultante da morte celular programada. Assim, acredita-se que a caracterização morfológica da formação dos cistos ovarianos em D. saccharalis forneceu informações valiosas para o entendimento das etapas iniciais da oogênese e contribuiu para o conhecimento dos mecanismos celulares relacionados com a produção de oócitos e com a reprodução nos insetos.

Morphology and ultrastructure of the male accessory glands of Achroia grisella (Fabricius)(Lepidoptera, Pyralidae)

The adult male reproductive system of Achroia grisella consists of paired testes in a common oval sheath, paired deferent ducts, accessory glands, seminal vesicles and a single ejaculatory duct. In this work, we used light and transmission electron microscopy to study the morphology of the male reproductive accessory glands of A. grisellla. The accessory gland consisted of glandular cells with a well-developed rough endoplasmic reticulum and Golgi apparatus, although no secretion was seen in the cells. Histochemical analysis showed that the accessory gland secretion consisted of glycoproteins. The variable morphological appearance of the secretion (globular, amorphous and fibrillar) present in the gland lumen and its staining properties, which changed along the gland tract, suggested that the secretion underwent some form of processing that was possibly associated with its maturation before release from the gland. We suggest that the accessory gland secretion may have a role in the maintenance of spermatozoa and/or in plug formation, as already reported for other lepidopteran species.

Morfología de huevos de siete especies de nóctuidos de Chile (Lepidoptera: Noctuidae)y clave actualizada para su identificación / Egg morphology of seven noctuid species (Lepidoptera: Noctuidae) from Chilean and updated key to their identification

Eggs from seven Noctuid moth species, Eriopyga perfusca (Hampson), Magnagrotis oorti (Koehler), Pseudoleucania brosii (Koehler), Scania simillima (Koehler), Scriptania americana (Blanchard), Scriptania leucofasciata Rodríguez, were collected at La Mina, 925 msnm, (35º 21’ S; 71º 41’ W) and Paso Internacional Pehuenche (35º 57’ S; 70º 23’ W), 2560 msnm, Chile. The Scanning Electron Microscope showed that egg morphology allows identification to species level. This is particularly useful in agricultural pest control, and morphological differences are used in this report to present an updated taxonomic key to the Chilean Noctuidae

Se obtuvieron huevos de siete especies de nóctuidos chilenos: Eriopyga perfusca Hampson, Scriptania americana (Blanchard), Scriptania leucofasciata Rodríguez, Magnagrotis oorti (Koehler), Pseudoleucania brossi (Koehler) y Scania simillima (Koehler) de La Mina, VII Región, 925 m, (35º 21’ S, 71º 41’ W) y Paso Internacional Pehuenche, 2560 m, (35º 57’ S, 70º23’ W). Se fotografiaron entre cuatro y nueve huevos de cada especie con Microscopia Electrónica de Barrido para analizar las variaciones entre las celdas primarias y secundarias. Los resultados morfológicos fueron utilizados para actualizar la clave taxonómica de las especies de nóctuidos chilenos

The windows, scales, and bristles of the tropical moth Rothschildia lebeau (Lepidoptera: Saturniidae)

The common Spanish name of the moth Rothschildia lebeau (Saturniidae)is cuatro ventanas (four ‘windows ’),because it exhibits a transparent oval path in each wing.The scales of the colored areas and the bristles from the "window "were analyzed.We developed a simple device to measure transmittance across the "windows "with an spectrophotometer.A square section of "window "was mounted onto a flat black card and placed onto a clamp that hung in the path of the light -beam of the spectrophotometer.Absorbance was measured at 350 and 550 nm,with the "window "positioned perpendicular to the light beam (incidence of 90 °);then the measurements were repeated with the "window "moved at an angle of 45 °.Each measurement was replicated 5 times.Wing color spots were analyzed with a light dissection microscope (stereoscope)and with scanning electron microscopy.The scales have a minimum of 4 morphological types,3 of them showed the typical appearance of unspecialized scales described for other butterflies; whereas the fourth has features particular to this species. On the "window "the scales are transformed in hair-like bristles that do not interfere with light, conferring the transparency that characterizes the "windows ".However,if the wing is illuminated at an almost grazing-incidence,they reflect the light as a mirror.Two hypothetical functional explanation for the windows are mimicry and interspecies communication

El nombre común de la mariposa nocturna Rothschildia lebeau (Saturniidae)es "cuatro ventanas ",porque exhibe una zona transparente en cada ala.Las escamas de las áreas coloreadas y las cerdas de las "ventanas "fueron analizadas al estereoscopio y al microscopio electrónico de rastreo. Al menos se identificaron cuatro tipos morfológicos de escamas similares a las escamas no especializadas de otras mariposas.En la "ventana "las escamas han sido sustituidas por cerdas que no interfieren el paso de la luz,confiriéndoles la transparencia que las caracteriza.No obstante,si el ala es iluminada en ángulo rasante refleja la luz como un espejo.Dos hipótesis para explicar la evolución de estas "ventanas "son el mimetismo y la comunicación

Ultrastructural localization of glycoconjugates in spermatozoa of the noctuid moth Anticarsia gemmatalis (inseta, lepidoptera, noctuidae)

The presence of glicoconjugates in apyrene and eupyrene spermatozoa of the noctuid moth Anticarsia gemmatalis was examined using ruthenium red and direct lectin-gold labeling techniques. Acid mucopolysaccharides of the plasma membrane of apyrene spermatozoa and the lacinante appendages of eupyrene spermatozoa were stained by ruthenium red. The lacinated appendages of eupyrene spermatozoa were the most intensely labeled structures when were used as histochemical probes. Sugar residues were also present in the dense cap of apyrene spermatozoa and in the nucleus of eupyrene spermatozoa. There was no labeling in the acrosome of eupyrene spermatozoa. These results indicate that the two categories of spermatozoa have different types and distributions of glycoconjugates which probably reffect their distinct fuctions during differentiation and fertilization.

Ultrastructure of the ovariole sheath in Diatraea saccharalis (Lepidoptera: Pyralidae)

The ultrastructure of the ovariole sheath along the Diatraea saccharalis ovariole was studied by scanning and transmission electron microscopy. Each ovariole is surrounded by an epithelial sheath, a tunica propria and scattered lumen cells. These three components of the ovariole sheath show different ultrastructural features along the ovariole, in the germarium or in the vitellarium; these differences are more evident in the epithelial sheath cells. The epithelial sheath is composed by two layers of cells, the external one running longitudinally and the internal one running circularly in the ovariole. These cells, in vitellarium, present cytoplasmic bundles of myofilaments that are arranged parallel to the long axis of the cells; these myofilaments are apparently related to the contraction movements of the follicles within the ovariole. The acellular tunica propria, composed of finely filamentous material, is attached to the adjacent follicle cells by adhesive dense plates. Between the epithelial sheath and the tunica propria there is a population of lumen cells, with morphological features of secretory activity.