Ultrastructural studies of the mandibular glands of the minima, media and soldier ants of Atta sexdens rubropilosa (Forel 1908)

The mandibular glands of Hymenoptera are structures associated with the mandibles and constitute part of the salivary glands system. Histological studies in workers of Atta sexdens rubropilosa revealed that this gland contains two portions: a secretory and a storage portion or reservoir. Both portions are connected by means of canaliculi. The object of the present work was the study of the ultratructure of the mandibular glands of minima, media and soldier ant of A. s. rubropilosa by TEM techniques. The glands, in the three castes studied, possess a reservoir, constituted by a simple pavementous epithelium surrounded by the cuticular intima and the secretory portion is constituted by cells of rounded shape. The secretory cells, mainly of minima and soldier, were rich in smooth endoplasmic reticulum. The media worker and soldier presented a large number of mitochondria, of varying shape. Well-developed Golgi complexes were also present in the soldiers. The secretory cells in minima, media and soldier were provided with collecting intracellular canaliculi, which were linked to the reservoir through the extracellular portion. The cytoplasm of the canaliculi-forming cell was poor in organelles. In the individuals of the three castes of A. s. rubropilosa, the presence of lipid secretion granules suggested, beyond the other functions, also a possible pheromonal action. The different roles executed by the different insect castes are directly dependent on the glandular products and, consequently, on the secretory cellular characteristics. (c) 2005 Elsevier Ltd. All rights reserved.

Morphology of the sternal gland in workers of Coptotermes gestroi (Isoptera, Rhinotermitidae)

The sternal gland is considered the only source of trail pheromones in termites. The morphology of the sternal gland was investigated in workers of Coptotermes gestroi using transmission and scanning electron microscopy. The results showed a small bilobed gland at the anterior part of the fifth abdominal sternite. The cuticular surface of the sternal gland showed a V-shaped structure with two peg sensilla in elevated socket and various campaniform sensilla. Pores and cuticular scale-like protuberances also occur in the glandular area. The ultrastructure showed a gland composed of class I cells and two different types of class 3 cells distinguished by location, different size and electron-density of secretory vesicles. Small class 3 cells (type 1) of the anterior lobe are inserted among class I cells and have weakly electron-dense vesicles associated with mitochondria, glycogen and smooth endoplasmic reticulum. The class 3 cells (type 2) of posterior lobe showed many round electron-lucent vesicles of secretion, abundant free ribosomes and a well-developed Golgi apparatus. Each class 3 cell is connected to the cuticle by a cuticular duct constituted by the receiving canal and the conducting canal. The secretion of class I cells is stored in an inner subcuticular reservoir that is delimited by the microvilli of these cells. This inner reservoir is large and crossed by the campaniform sensilla and ducts of two types of class 3 cells that open outside of the insect body. An exterior reservoir also is present between the fourth and fifth sternite. The complex structure of the sternal gland suggests multicomponents for the trail pheromone in the worker of C gestroi. (c) 2005 Elsevier Ltd. All rights reserved.

Ultramorphological characteristics of Chrysomya megacephala (Diptera, Calliphoridae) eggs and its eclosion

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The functional morphology of the metapleural gland of the leaf-cutting ant Atta laevigata (Formicidae: Attini)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Ultrastructural profile of metapleural gland cells of the ant Atta laevigata (F. Smith, 1858) (Formicidae: Attini)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morphological Organization of the Dorsal Protuberance of Linepithema humile (Mayr, 1868) Ant's Larvae (Hymenoptera, Formicidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Anatomia foliar de Erythroxylum P. Browne (Erythroxylaceae) do Cerrado do Estado de São Paulo, Brasil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Conservação pós-colheita de abacaxi 'Pérola' colhido no estádio de maturação pintado associando-se refrigeração e atmosfera modificada

Estudou-se a manutenção da qualidade do abacaxi 'Pérola', utilizando-se de refrigeração e atmosfera modificada. Os frutos foram armazenados em ambiente com controle de temperatura a 8ºC e 90%UR, durante 17 dias, quando foram transferidos para condição de ambiente (25ºC, 75-80%UR). Eles foram avaliados na recepção, caracterizando-os, após 5; 9; 13 e 17 dias sob refrigeração, e depois de transferidos para as condições de ambiente, aos 21; 25 e 29 dias. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial (6 x 8), tendo-se seis tratamentos (testemunha, duas ceras e três filmes plásticos) e oito épocas de avaliação. Os frutos foram avaliados quanto à coloração, ocorrência de podridões e de escurecimento interno, e a polpa avaliada quanto ao pH e aos teores de sólidos solúveis totais (SST), acidez total titulável (ATT), ácido ascórbico e açúcares solúveis, totais e redutores. Durante o armazenamento, observaram-se o amarelecimento dos frutos, o aumento no pH, na relação SST/ATT, e nos teores de açúcares solúveis, totais e redutores, que foram maiores após a transferência dos frutos para o ambiente. Os sintomas de injúria por chilling aumentaram com o tempo de armazenamento. Os tratamentos que modificam a atmosfera (embalagens e ceras) não influenciam significativamente nos principais atributos de qualidade do abacaxi 'Pérola', mas o uso de embalagem com PEBD e PVC atrasou o aparecimento de sintomas de escurecimento interno após a transferência dos frutos para a condição ambiente. Os frutos sem embalagem e os tratados com cera mostraram-se mais sensíveis à injúria por chilling, que se manifestou aos quatro dias após a remoção para o ambiente. A embalagem em PEBD e PVC retardou o aparecimento dos primeiros sintomas, em quatro dias.

Estrutura e desenvolvimento dos tricomas secretores em folhas de Piper regnellii (Miq.) C. DC. var. regnellii (Piperaceae)

Nesta espécie ocorrem dois tipos de tricomas secretores: glândula perolada e tricoma saculiforme. Ambos originam-se na protoderme do primórdio foliar e atingem sua maturidade nas folhas jovens presentes no ápice caulinar. A densidade dos dois tipos de tricomas diminui durante a expansão do limbo, sendo raros na folha adulta. As glândulas peroladas são constituídas por uma célula basal e por uma célula apical grande cuja forma varia de semi-globóide a espatulada. A liberação da secreção ocorre após a ruptura da cutícula distendida. Os tricomas saculiformes são constituídos por uma célula basal, 1-2 células colares e uma célula apical cônica, de posição inclinada à superfície foliar. A secreção acumula-se em espaços subcuticulares diminutos, não tendo sido observada ruptura da cutícula.

Avaliação farmacognóstica da própolis da região de Maringá

Os autores propõem procedimentos para estabelecer o controle de qualidade da própolis. Para tanto, foram adaptadas e executadas técnicas farmacopéicas e/ou desenvolvidas técnicas novas. Foram estabelecidos perfis dos teores de flavonóides, de ceras, de substâncias voláteis totais (através da perda por dessecação) e de cinzas totais. Os valores obtidos para as amostras de própolis estudadas, coletadas em um apiário-escola, foram comparados com os de própolis adquiridas no mercado. Foi estabelecido, ainda, o perfil destes parâmetros para amostras de própolis coletadas nos diferentes locais da colméla, no periodo de três anos, com coletas de inverno e verão. Os teores de flavonóides variaram entre 2,05 - 5,52%.

Droplet deposition during spray and leaf pH in aquatic weed control

A diversidade morfológica da superfície foliar existente entre as espécies de plantas e a presença de estruturas foliares como tricomas, estômatos, cutícula e ceras podem exercer grande influência na aderência e deposição das gotas de pulverização, assim como na absorção do herbicida. Desta forma, o objetivo do presente trabalho foi estudar, em quatro espécies de plantas daninhas aquáticas (Enhydra anagallis, Eichhornia crassipes, Heteranthera reniformis e Typha subulata), a área de molhamento de gotas de pulverização nas superfícies foliares adaxial e abaxial, bem como o pH foliar. O experimento foi realizado em Botucatu-SP. As plantas foram cultivadas em caixas d'água sob condições de campo, e quando atingiram seu pleno desenvolvimento (antes do florescimento), foram realizadas as avaliações de pH foliar e da área de molhamento de gotas de pulverização. As tensões superficiais das gotas aplicadas (0,5 mL), apresentadas pelas soluções de glyphosate aplicado isolado a 5,0% v v-1 (Rodeo 480 g L-1 e.a. produto comercial), glyphosate + Aterbane BR (5,0% + 0,5% v v-1), glyphosate + Silwet L-77 (5,0% + 0,05% v v-1), além das soluções com os adjuvantes isolados, Aterbane BR (0,5% v v-1) e Silwet L-77 (0,05% v v-1) foram respectivamente 72,1; 28,7; 23,3; 37,3 e 22,1 mN m-1. As médias obtidas de pH foliar variaram entre 5,50 e 7,50, destacando-se a espécie E. anagallis com valores de 6,68 e 7,02 para as faces adaxial e abaxial, respectivamente. Dentre as plantas daninhas aquáticas avaliadas T. subulata foi a espécie que apresentou as maiores médias de área de molhamento nas faces adaxial e abaxial da folha, proporcionada pelas as soluções de glyphosate + Aterbane BR, glyphosate + Silwet L-77 e Silwet L-77, com valores de 12,99-7,03; 20,04-17,95 e 31,81-25,91 mm², respectivamente.

Ultrastructure of the excretory duct in the silk gland of the sugarcane borer Diatraea saccharalis (Lepidoptera : Pyralidae)

The excretory duct in the silk gland of the sugarcane borer Diatraea saccharalis consists of two morphologically distinct regions, recognized by scanning and transmission electron microscopy. The thin posterior region, adjacent to the glandular region, presents a regular surface. Secretory vesicles containing either electron-dense or fibrillar cuticular-like materials are observed in their apical cytoplasm; the same cuticular materials were detected as extracellular deposits among the microvilli. The short anterior region, near the common duct, exhibits surface protrusions; there are no secretory vesicles in their apical cytoplasm. These results show that only the duct cells at the posterior region are involved in the secretion of the cuticular intima elements. Desmosome-like structures were visualized linking together adjacent microvillar membranes only in the cells of anterior duct region, with unknown function. The transition between the duct and the glandular region is abrupt; the cells of the glandular and posterior duct regions present large amounts of microtubules. Nerve fibers can be observed between the duct cells in their two regions, suggesting that control of silk secretion may occur in the excretory duct via neurotransmitter liberation. (C) 2002 Elsevier B.V. Ltd. All rights reserved.

Effect of constituents of the foliar wax of Didymopanax vinosum on the foraging activity of the leaf-cutting ant Atta sexdens rubropilosa

Leaf epicuticular waxes may affect substrate selection by leaf-cutting ants, and host recognition by several phytophagous insects. The influence of the crude epicuticular wax of Didymopanax vinosum E. March. (Araliaceae), and its major constituents lupeol and free primary alcohols, on substrate selection by the leaf-cutting ant Atta sexdens rubropilosa Forel, was investigated. Two ant colonies were used in laboratory bioassays. Corn flakes (zea) were impregnated with chloroform solutions of the substances being tested and fed to the adults. One of the colonies gave results, in most of the tests, not significantly different from the controls. The other colony, however, discriminated against the crude wax, a strong deterrent effect being observed from the first of a series of eight trials. The same colony was able to discriminate against lupeol after the second trial. The fraction of primary n-alcohols (22% C28, 66% C30 and 12% C32) deterred feeding only after the fifth trial. The results demonstrate that some constituents of epicuticular waxes may deter the foraging activity of A. sexdens rubropilosa, depending, however, on the colony under observation. It is suggested that lupeol, of the foliar wax of D. vinosum, is an important deterrent to leaf-cutting ants, although with less pronounced effects than those observed in tests with the crude wax.

Chemical analysis of different larval instars and tissues of Pachycondyla (=Neoponera) villosa (Hymenoptera: Formicidae, Ponerinae)

Chemical analyses of complete larvae of the first to third instar and cuticle, fat body and salivary glands extracts of fourth instar larvae using gas chromatography and gas chromatography-mass spectrometry, were performed upon Pachycondyla villosa. The results revealed that P. villosa larvae do not produce a pheromone, as only fatty acids and n-alkanes were detected. After quantifying the identified compounds, it was determined that the fat body is the main place of storage and/or production of the cuticular hydrocarbons. It was also observed that the absolute quantity of cuticular hydrocarbons increases progressively during larval development. Inferences about the transport behavior of matured larvae to the pupation place and the colony odor are discussed.

Contribuição ao protocolo de controle de qualidade da própolis e de seus extratos

A quality control protocol for the analysis of propolis and its extracts is proposed in the present work. Propolis of Apis mellifera L. bees collected in beehives of an apiary located in the northwest of the Paraná State was triturated and submitted to the following analysis: particles medium size determination, loss of dry, ashes drift, waxes drift, drift of extractive (in water and in ethanol) and total flavonoids drift determination. Propolis ethanolic extracts (96 °GL) at 10% (w/w) and at 30% (w/w) were prepared and submitted to the determination of the pH, relative density, dry residue, alcoholic drift and total flavonoids drift determination. Propolis was analyzed, through High Performance Liquid Cromatography (HPLC). Comparing the obtained results with other works, it was observed that is possible to establish the intervals of values for parameters in order to evaluate the quality of a propolis sample and its extracts.