Effects of season and latitude on the diet quality of the invasive Asian shore crab Hemigrapsus sanguineus

Invasive species alter invaded ecosystems via direct impacts such as consumption. In turn, an invasive species’ ability to thrive in new habitats depends on its ability to exploit available resources, which may change over time and space. Diet quality and quantity are indicators of a consumer’s consumptive effects and can be strongly influenced by season and latitude. We examined the effects of season and latitude on the diet quality and quantity of the invasive Asian shore crab Hemigrapsus sanguineus throughout a non-winter sampling year at 5 different sites spanning 8° of latitude across its invaded United States range. We found that diet quality, averaged through time, largely follows an expected latitudinal cline, being higher in the center of its range and lower toward the southern and northern edges. We also found that while some sites show similar patterns of diet quality variation with season, no pattern is consistent across all latitudes. Finally, we found that crabs at sites with low diet quality during summer reproductive months did not compensate by increasing total consumption. Because the Asian shore crab is an important consumer in its invaded ecosystems, understanding how its diet quality and quantity vary with season and latitude can help us better understand how this species influences trophic interactions and community structure, how it has been able to establish across a wide ecological and environmental range, and where future range expansion is most likely to occur.Temple University. College of Science and TechnologyBiolog

Antibiose e não preferência para oviposição de Bemisia tabaci (Genn.) biótipo B (Hemiptera: Aleyrodidae) por cultivares de Vigna unguiculata (L.) Walp

The objective of this study was to identify cowpea cultivars resistant to B. tabaci biotype B and the respective resistance types involved. The experiments were conducted in a greenhouse at the Departamento de Fitossanidade da Faculdade de Ciências Agrárias e Veterinárias, UNESP/Campus de Jaboticabal, SP, Brasil, from November 2009 to April 2010. Tests for non-preference for oviposition and antibiosis were performed. The experimental design consisted of randomized blocks for the choice test and completely randomized for the no-choice tests and the antibiosis test. It was concluded that the BRS Urubuquara, IPA-206 and BR17 Gurgueia cultivars present non-preference for whitefly oviposition resistance; the BRS Urubuquara cultivar presents non-preference and antibiosis resistance; the Sempre Verde cultivate is susceptible to oviposition; and the whitefly prefers to deposit eggs on the leaves' abaxial face in the upper position of the plant.O objetivo deste trabalho foi identificar cultivares de caupi resistentes a B. tabaci biótipo B e os respectivos tipos de resistência envolvidos. Os experimentos foram conduzidos em casa de vegetação no Departamento de Fitossanidade da Faculdade de Ciências Agrárias e Veterinárias, UNESP/Campus de Jaboticabal, SP, no período de novembro de 2009 a abril de 2010. Realizaram-se testes de não preferência para oviposição e antibiose. O delineamento experimental utilizado foi de blocos casualizados para o teste com chance de escolha e inteiramente casualizado para os testes sem chance de escolha e teste de antibiose. Conclui-se que os cultivares BRS Urubuquara, IPA-206 e BR17 Gurgueia apresentaram resistência do tipo não preferência para oviposição da mosca-branca; a cultivar BRS Urubuquara apresenta resistência de tipo antibiose; a cultivar Sempre Verde é suscetível; e, mosca-branca prefere ovipositar na posição superior das plantas.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Universidade Estadual Paulista, Laboratório de Resistência de PlantasUniversidade Estadual Paulista, Departamento de FitossanidadeUniversidade Federal Rural da Amazônia, Departamento de Biologia Vegetal e Fitossanidad

Não preferência para oviposição e alimentação por Tuta absoluta (Meyrick) em genótipos de tomateiro

Este trabalho buscou selecionar genótipos de tomateiro resistentes a Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), dos tipos não preferência para oviposição e alimentação, em testes com e sem chance de escolha. As espécies utilizadas foram Solanum lycopersicum L. (cv. Santa Clara, os híbridos: Saladete Italiano Ty Tyna, Santa Cruz Débora Ty, Salada Lumi, Saladete Italiano Andrea Victory e Santa Cruz Ty Carina Ty), S. habrochaites S. Knapp & D.M Spooner (linhagens PI 134417 e PI 134418) e S. pimpinellifolium L. (linhagens NAV 1062 e PI 126931). Nos testes de não preferência para oviposição, foram contados o número de ovos por planta às 24, 48 e 72 horas, após a liberação dos adultos. Para os testes de não preferência para alimentação, foram avaliados a atratividade das larvas pelos genótipos em cada repetição a 1, 3, 5, 10, 30, 60, 120, 360, 720 e 1440 minutos, após a liberação das larvas e massa consumida pelas larvas. Constatou-se que os genótipos de tomateiro avaliados não apresentam resistência dos tipos não preferência para oviposição. Já o genótipo PI 134417 apresenta resistência do tipo não preferência para alimentação.This study aimed to select tomato genotypes resistant to Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) due to nonpreference for oviposition and feeding, in CHOIce and no-CHOIce tests. The species used were Solanum lycopersicum L. (cv. Santa Clara, hybrids: Saladete Italian Ty Tyna, Santa Cruz Débora Ty, Salad Lumi, Saledete Italian Andrea Victory and Santa Cruz Ty Carina Ty), S. habrochaites S. Knapp & D.M Spooner (lines PI 134417 and PI 134418) and S. pimpinellifolium L. (lines NAV 1062 and PI 126931). In tests of nonpreference for oviposition the number of eggs per plant was counted at 24, 48 and 72 hours after the release of adults. For the tests of nonpreference for feeding the attractiveness of the larva to the genotypes in each replicate was assessed at 1, 3, 5, 10, 30, 60, 120, 360; 720 and 1440 minutes after the release of larvae and mass consumed by the larva. It was found that the tomato genotypes evaluated did not present nonpreference resistance for oviposition. However, the genotype PI 134417 presented nonpreference resistance for feeding.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Departamento de FitossanidadeUniversidade Estadual Paulista Faculdade de Ciências Agrárias e Veterinárias Departamento de Fitossanidad

The persistent shadow of the supermassive black hole of M87: II. Model comparisons and theoretical interpretations

The Event Horizon Telescope (EHT) observation of M87∗ in 2018 has revealed a ring with a diameter that is consistent with the 2017 observation. The brightest part of the ring is shifted to the southwest from the southeast. In this paper, we provide theoretical interpretations for the multi-epoch EHT observations for M87∗ by comparing a new general relativistic magnetohydrodynamics model image library with the EHT observations for M87∗ in both 2017 and 2018. The model images include aligned and tilted accretion with parameterized thermal and nonthermal synchrotron emission properties. The 2018 observation again shows that the spin vector of the M87∗ supermassive black hole is pointed away from Earth. A shift of the brightest part of the ring during the multi-epoch observations can naturally be explained by the turbulent nature of black hole accretion, which is supported by the fact that the more turbulent retrograde models can explain the multi-epoch observations better than the prograde models. The EHT data are inconsistent with the tilted models in our model image library. Assuming that the black hole spin axis and its large-scale jet direction are roughly aligned, we expect the brightest part of the ring to be most commonly observed 90 deg clockwise from the forward jet. This prediction can be statistically tested through future observations

First M87 Event Horizon Telescope results. IX.: detection of near-horizon circular polarization

Galaxie