Comparative morphology of the mandibles of female polistine social wasps (Hymenoptera, Vespidae, Polistinae)

Comparative morphology of the mandibles of female polistine social wasps (Hymenoptera, Vespidae, Polistinae). Diversity of mandibular forms in female polistines is explored and compared among 116 species of all polistine genera. Inferences about function are made and discussed based on observed form differences. Mandible length and width measurements are analyzed for a subset of polistine species plus two vespines and two eumenines. A variable expressing the ratio between these variables is also considered in morphometric analyses. The following mechanical interactions among mandible structural elements are highlighted: opposition and crossing of mandibles' apical teeth at the middle of the closing trajectory; shearing action of the apical teeth against mesial denticles of the opposite mandible; shearing action of the mandible anterior margin against the ventral margin of the clypeus. In the genera Agelaia and Angiopolybia, exceptionally developed mesial mandibular structures may be related to necrophagy. In some epiponine genera, poorly developed mesial denticles and strong torsion of mandibles may be partially related to use of short wood fibers in nest construction as advanced by Sarmiento (2004). The considerable morphological variation found across the subfamily Polistinae is certain to be important in taxonomic and phylogenetic studies at the genus and species levels.

Description of the male of Lepidodexia (Xylocamptopsis) teffeensis (Townsend) (Diptera, Sarcophagidae)

Description of the male of Lepidodexia (Xylocamptopsis) teffeensis (Townsend) (Diptera, Sarcophagidae). The male of Lepidodexia (Xylocamptopsis) teffeensis (Townsend, 1927) is described and illustrated for the first time based on material housed in the entomological collection of Museu Nacional, Rio de Janeiro (MNRJ). This monotypic subgenus has been recorded in the Brazilian Amazon Rainforest, first in the state of Amazonas and now in the state of Pará. The general structure of the male terminalia is similar that of other Lepidodexia, especially of the subgenus Lepidodexia, by the short distiphallus, juxta with apical projection, and vesica with a membranous spinous lobe.

Leptohyphidae (Insecta, Ephemeroptera) do estado do Amazonas, Brasil: novos registros, nova combinação, nova espécie e chave de identificação para estágios ninfais

Leptohyphidae (Insecta, Ephemeroptera) do Estado do Amazonas, Brasil: novos registros, nova combinação, nova espécie e chave de identificação para estágios ninfais. Os seguintes gêneros de Leptohyphidae ocorrem no estado do Amazonas: Amanahyphes Salles & Molineri, Leptohyphes Eaton, Tricorythodes Ulmer e Tricorythopsis Traver. A distribuição das espécies de Leptohyphidae no Estado do Amazonas é apresentada. Uma espécie nova, Tricorythodes yapekuna sp. nov., é descrita e pode ser diferenciada de outros Tricorythodes pelas (1) garras tarsais com um par de dentículos submarginais e sem dentículos marginais; (2) palpo maxilar biarticulado; (3) brânquia opercular uniformemente preta com exceção da margem apical; (4) fórmula branquial 2/3/3/3/2; e (5) margem lateral do abdome expandida nos segmentos III_VI. Uma combinação nova, Tricorythopsis rondoniensis (Dias, Cruz & Ferreira, 2009) comb. nov., é proposta e constitui o primeiro registro dessa espécie para o Estado do Amazonas. Uma chave dicotômica ilustrada para identificar ninfas de gêneros e espécies ocorrentes no Amazonas também é apresentada.

Description of the male of Evandromyia gaucha Andrade Filho, Souza, Falcão (Psychodidae, Phlebotominae)

Here, we present the description of male of the sand fly species Evandromyia gaucha. Six male specimens of E. gaucha, together with conspecific females, were collected in native forest areas of the municipalities of Porto Alegre, Caçapava do Sul (type locality of E. gaucha) and Santa Cruz do Sul, in Rio Grande do Sul state, Brazil. The specimens are distinguished from other species of the rupicola series of the genus Evandromyia by the presence of dilatation in the apical quarter of the genital filaments followed by tapering of the final portion.

Description and life history of a new cecidogenous species of Palaeomystella Fletcher (Lepidoptera, Momphidae) from Brazil

ABSTRACTMale, female, pupa, and last-instar larva of Palaeomystella beckeri (Moreira and Basilio) a new species from the Atlantic forest, southern Brazil, are described and illustrated with the aid of optical and scanning electron microscopy. Larvae induce galls on apical branches of Tibouchina trichopoda (DC.) Baill. (Melastomataceae) within which pupation occurs. Gall description and preliminary data on life history are also provided.

Behavior of Eucalyptus grandis and E. cloeziana seedlings grown in arsenic-contaminated soil

Arsenic has been considered the most poisonous inorganic soil pollutant to living creatures. For this reason, the interest in phytoremediation species has been increasing in the last years. Particularly for the State of Minas Gerais, where areas of former mining activities are prone to the occurrence of acid drainage, the demand is great for suitable species to be used in the revegetation and "cleaning" of As-polluted areas. This study was carried out to evaluate the potential of seedlings of Eucalyptus grandis (Hill) Maiden and E. cloeziana F. Muell, for phytoremediation of As-polluted soils. Soil samples were incubated for a period of 15 days with different As (Na2HAsO4) doses (0, 50, 100, 200, and 400 mg dm-3). After 30 days of exposure the basal leaves of E. cloeziana plants exhibited purple spots with interveinal chlorosis, followed by necrosis and death of the apical bud at the 400 mg dm-3 dose. Increasing As doses in the soil reduced root and shoot dry matter, plant height and diameter in both species, although the reduction was more pronounced in E. cloeziana plants. In both species, As concentrations were highest in the root system; the highest root concentration was found in E. cloeziana plants (305.7 mg kg-1) resulting from a dose of 400 mg dm-3. The highest As accumulation was observed in E. grandis plants, which was confirmed as a species with potential for As phytoextraction, tending to accumulate As in the root system and stem.

EFEITO DE TRICOMAS, ALELOQUÍMICOS E NUTRIENTES NA RESISTÊNCIA DE LYCOPERSICON HIRSUTUM À TRAÇA-DO-TOMATEIRO

Estudos foram conduzidos com o objetivo de verificar o efeito de tricomas, aleloquímicos e nutrientes nas folhas de partes do dossel das plantas na resistência de Lycopersicon hirsutum à traça- do-tomateiro, Tuta absoluta (Lepidoptera: Gelechiidae). Foram quantificados os teores de 2-tridecanona (2-TD), 2-undecanona (2-UD), N, P, K, Ca e Mg, densidade e tipos de tricomas e tamanho das folhas nos terços apical, mediano e basal do dossel de plantas de L. hirsutum e de L. esculentum e estudaram- se os efeitos destes fatores sobre características biológicas de T. absoluta. Observou-se elevação no teor de 2-TD da base para o ápice do dossel. Não se detectou diferença significativa quanto ao número de ovos de T. absoluta ao longo do dossel de L. hirsutum, constatando-se em L. esculentum maior oviposição nos terços apical e mediano do que no basal. As folhas do terço apical de L. hirsutum apresentaram maior efeito deletério sobre as larvas de traça.

Occurrence and structure of extrafloral nectariesin Pterodon pubescens Benth. and Pterodon polygalaeflorus Benth.

Extrafloral nectaries (EFNs) are structurally variable and widely spread among the angiosperms. The occurrence of EFNs in leaves of Pterodon polygalaeflorus Benth. and Pterodon pubescens Benth. (Fabaceae: Papilionoideae) were detected in adult specimens, at the time of production of new buds and flowers. The goals of the present study are to register the occurrence of the EFNs in P. pubescens and P. polygalaeflorus, and provide comparative data on the anatomical structures. The EFNs occur in the rachis and are located under the insertion of each petiolule. Each nectary consists of a small elevation whose apical portion is deeply invaginated, resulting in a depression (secretory pole), a common characteristic of both species. Unicellular, nonglandular trichomes occur along the rachis, being less numerous in P. polygalaeflorus while in P. pubescens they cover the EFNs. The secretory tissue consists of parenchyma cells with dense cytoplasm compactly arranged. The nectar reaches the surface of the EFNs by rupturing the thin cuticle which covers the secretory pole, since both species lack stomata or any other interruption at the epidermis. The basic difference between the two species, in relation to the EFNs, is the density of the pubescence, which is always greater in P. pubescens. Structural and dimensional modifications may be observed, even between basal and apical nectaries in the same rachis, so it does not constitute a taxonomical tool.

Preservation of rhizobia by lyophilization with trehalose

The objective of this study was to determine if trehalose can effectively enhance the viability and storage lifetime of Rhizobium tropici and Rhizobium etli after lyophilization as compared to the traditional protective combination of sucrose and peptone. Two strains of bean-nodulating rhizobia were effectively preserved in the lyophilized state by 100 mM trehalose, and survived for at least 12 days, even when stored under non-ideal conditions. Trehalose provided better protection than the sucrose/peptone combination. When protective excipients were introduced inside the cells, strain CFN 42 was more sensitive to the type of additive used than strain CIAT 899, probably because CIAT 899 produces beta (1-2) glucan, which may have a protective effect. beta (1-2) glucan combined with sucrose protected better than trehalose against leakage from freeze-dried liposomes, but by itself it had no protective capability. There was a high level of unfrozen water associated with the hydrated glucan, in addition to a thermal event at approximately 70ºC, corresponding to an observed gel-sol transition in the glucan. These findings may shed light on the mechanism by which the glucan contributes to the protection of dried cells and liposomes, and may lead to further improvements in rhizobial inoculants.

Factors affecting attack rate of whitefly on the eggplant

The objective of this study was to determine the effects of weather, predators and parasitoids, canopy height and plant age, leaf chemical composition, levels of leaf N and K and leaf trichomes on the intensity of Bemisia tabaci attack on Solanum melongena. A higher density of nymph and whitefly adults was recorded at the base and medium of the plant compared to the apex. A higher number of eggs was observed on the medium part than on the apical and base part of the plants dossel. An increase in the density of whitefly is associated with an increase in temperature.

Deposição de agrotóxicos pulverizados na cultura da maçã

O objetivo deste trabalho foi avaliar a distribuição da deposição de agrotóxicos pulverizados em duas cultivares de maçã (Malus domestica Borkh). Uma calda com traçador Rodamina B foi pulverizada, com equipamento do tipo carreta com cortina de ar, com dois tipos de calibrações. Em uma calibração foram utilizados bicos cones JA-1, JA-2 e JA-3 e na outra, bicos leque AVI 110 ISO-04 e bicos JA-1. Não houve diferenças entre as calibrações, mas a deposição nas plantas foi decrescente da região apical para a basal. Nas calibrações testadas, 25% do traçador aplicado perdeu-se no solo.

Plano de amostragem do biótipo B de Bemisia tabaci na cultura do pepino

A adoção de programas de manejo integrado de pragas permite reduzir a aplicação de inseticidas e os planos convencionais de amostragem representam o ponto inicial na geração desses programas. Assim, o objetivo deste trabalho foi determinar plano de amostragem convencional para o biótipo B da mosca-branca Bemisia tabaci Genn. (Hemiptera: Aleyrodidae) na cultura do pepino. Foram avaliadas as densidades de ninfas e de adultos em dez lavouras comerciais de pepino, Tocantins, MG, estudando nove sistemas amostrais formados pela combinação de três técnicas (batida de folha em bandeja de plástico branco, contagem direta dos insetos na face inferior da folha e coleta de folha em sacola de plástico) e três unidades amostrais (folha do terço apical, mediano ou basal do espaldeiramento). A contagem direta em folha do terço basal foi o sistema com maior precisão econômica na amostragem de ninfas, mas não possibilitou a geração de plano de amostragem praticável. As batidas, em bandeja, de folha dos terços apicais, medianos ou basais do espaldeiramento foram os sistemas economicamente mais precisos na amostragem de adultos. Desses, apenas a batida de folha do terço mediano em bandeja gerou plano de amostragem praticável, sendo que este plano é composto de 196 amostras/lavoura.

Rescue of a non-viable accession and rapd analysis of recovered plants of Arachis retusa

In vitro regeneration of Arachis retusa was examined for the purpose of germplasm renewal and conservation. Random amplified polymorphic DNA (RAPD) fingerprinting was used to evaluate the genetic stability of plants derived from embryo axes and apical segments. Ten arbitrary decamer primers were screened and five of them were selected. Ninety genomic regions were evaluated, with an average of 18 loci per clone. All amplified segments were monomorphic. The results indicate that recovered plants are genetically stable at the assessed genomic regions and that both regeneration processes are suitable for in vitro germplasm preservation of Arachis species.

Whitefly population dynamics in okra plantations

The control of whitefly Bemisia tabaci (Gennadius) biotype B (Hemiptera: Aleyrodidae) on okra (Abelmoschus esculentus L.) consists primarily in the use of insecticides, due to the lack of information on other mortality factors. The objective of this study was to evaluate the spatial and temporal population dynamics of the whitefly B. tabaci biotype B on two successive A. esculentus var. "Santa Cruz" plantations. Leaf chemical composition, leaf nitrogen and potassium contents, trichome density, canopy height, plant age, predators, parasitoids, total rainfall and median temperature were evaluated and their relationships with whitefly on okra were determined. Monthly number estimates of whitefly adults, nymphs (visual inspection) and eggs (magnifying lens) occurred on bottom, middle and apical parts of 30 plants/plantation (one leaf/plant). Plants senescence and natural enemies, mainly Encarsia sp., Chrysoperla spp. and Coccinellidae, were some of the factors that most contributed to whitefly reduction. The second okra plantation, 50 m apart from the first, was strongly attacked by whitefly, probably because of the insect migration from the first to the second plantation. No significant effects of the plant canopy on whitefly eggs and adults distribution were found. A higher number of whitefly nymphs was found on the medium part than on the bottom part.

Caracterización de la generación segregante de un híbrido de tomate con genes nor y silvestres

El objetivo del trabajo fue estudiar en la generación segregante del híbrido entre una cultivar de Lycopersicon esculentum homocigota para el gen nor y la accesión LA1385 de L. esculentum var. cerasiforme, la recombinación de caracteres productivos y de calidad de fruto a través de las metodologías de análisis multivariado. En las generaciones F1 y F2 y en los progenitores se evaluaron caracteres vegetativos y productivos (longitud de entrenudos, perímetro del tallo en las partes basal, media y apical, número de flores por inflorescencia, número de inflorescencias por planta y días a cosecha) y de calidad de fruto (peso, forma, sólidos solubles, acidez, firmeza, color y vida poscosecha). Se utilizaron las correlaciones canónicas entre los caracteres vegetativos y productivos y los de calidad de fruto y también un análisis de agrupamiento para las características del fruto, incluyendo los progenitores, la F1 y la F2. Estos análisis permitieron demostrar que las características productivas y de calidad de fruto recombinaron en la generación segregante. La vida poscosecha fue la característica de los frutos más importante para discriminar grupos en la F2. Para tres niveles de agrupamiento cada grupo de individuos F2 se comportó como alguno de los progenitores o la F1.