Manipulation of fire ant density, Solenopsis spp., for short-term reduction of Diatraea saccharalis larval densities in Brazil

The sugarcane borer, Diatraea saccharalis (Fabr.) is the main sugarcane pest in Brazil. In the State of São Paulo, the main active population control of D. saccharalis is by inundative releases of the exotic parasitoid, Cotesia flavipes (Cam.). However, the production of C. flavipes in sugar mills entails costs and few studies have evaluated the effects of native predators on sugarcane borer populations. Using a simple colony translocation method, we evaluated the effect of fire ants (Solenopsis spp.) on population densities of D. saccharalis and concurrently upon rates of parasitism by classical biological control agents in the São João sugar mill in the State of São Paulo, Brazil. The translocation technique proved to be feasible and economically possible. Sugarcane borers were sampled in each of the 5 areas for each treatment in two 1.4 x 5.0 m (7 m²) points (sample size), by opening and visually examining all canes. The average numbers and its respective standard deviations (SD) for D. saccharalis population densities before and after colony translocations considering 0, 5, 10 and 15 colonies added per 0.5 ha were, 9.2 ± 5.9, 8.4 ± 3.4, 9.0 ± 6.9, 9.4 ± 8.1 and 3.2 ± 1.8, 2.8 ± 2.7, 2.6 ± 1.5, 3.8 ± 2.8, respectively. However, we detected no significant changes in sugarcane borer densities with respect to ant colony densities over a two-week period, none of which were greater than for no colony additions. No effects of colony translocations on parasitism rates of braconid and tachinid parasitoids on D. saccharalis were detected. Thus, although the translocation technique was economically feasible, no reductions of D. saccharalis densities were produced by colony additions, and may not be a viable alternative for D. saccharalis population reduction, especially at the low population levels which prevail in Brazil.A broca da cana-de-açúcar, Diatraea saccharalis (Fabr.) é a principal praga da cana-de-açúcar no Brasil. No Estado de São Paulo, o principal meio de controle desta praga é por meio de liberações constantes do parasitóide exótico Cotesia flavipes (Cam.). De qualquer forma, a produção de tais parasitóides nas usinas de cana-de-açúcar acarreta custos e poucos estudos tem avaliado os efeitos de predadores nativos nas populações da broca da cana-de-açúcar. Usando-se um método simples de coleta e liberação de colônias, avaliou-se o efeito de formigas Solenopsis spp. nas densidades das populações de D. saccharalis, bem como seu efeito na taxa de parasitismo imposta por agentes de controle biológico clássico. O estudo foi conduzido nos canaviais da Usina São João, município de Araras-SP. Esta metodologia mostrou ser apropriada e economicamente viável. Lagartas de D. saccharalis foram amostradas em cada uma das cinco áreas de cada tratamento em dois pontos de 1.4 x 5.0 m (7 m²) (tamanho amostral), através da abertura e observação de todas as plantas ali existentes. Os números médios e os respectivos desvios padrão para as densidades populacionais de D. saccharalis, antes e após a adição de 0, 5, 10 e 15 colônias por 0.5 ha, foram, 9,2 ± 5,9; 8,4 ± 3,4; 9,0 ± 6,9; 9,4 ± 8,1 e 3,2 ± 1,8; 2,8 ± 2,7; 2,6 ± 1,5; 3,8 ± 2,8; respectivamente. De qualquer forma, durante um período de duas semanas, nenhuma mudança significativa nas densidades de D. saccharalis foi detectada, as quais não diferiram das áreas onde não houve liberação de colônias. Nenhum efeito, devido à adição das colônias, nas taxas de parasitismo impostas pelos braconídeos e taquinídeos foi detectada. Portanto, embora esta metodologia foi economicamente viável, nenhuma redução nas densidades de D. saccharalis foi evidenciada devido à adição das colônias, não sendo uma alternativa viável para a redução das densidades populacionais de D. saccharalis

Evolutionary patterns and processes in the radiation of phyllostomid bats

<p>Abstract</p> <p>Background</p> <p>The phyllostomid bats present the most extensive ecological and phenotypic radiation known among mammal families. This group is an important model system for studies of cranial ecomorphology and functional optimisation because of the constraints imposed by the requirements of flight. A number of studies supporting phyllostomid adaptation have focused on qualitative descriptions or correlating functional variables and diet, but explicit tests of possible evolutionary mechanisms and scenarios for phenotypic diversification have not been performed. We used a combination of morphometric and comparative methods to test hypotheses regarding the evolutionary processes behind the diversification of phenotype (mandible shape and size) and diet during the phyllostomid radiation.</p> <p>Results</p> <p>The different phyllostomid lineages radiate in mandible shape space, with each feeding specialisation evolving towards different axes. Size and shape evolve quite independently, as the main directions of shape variation are associated with mandible elongation (nectarivores) or the relative size of tooth rows and mandibular processes (sanguivores and frugivores), which are not associated with size changes in the mandible. The early period of phyllostomid diversification is marked by a burst of shape, size, and diet disparity (before 20 Mya), larger than expected by neutral evolution models, settling later to a period of relative phenotypic and ecological stasis. The best fitting evolutionary model for both mandible shape and size divergence was an Ornstein-Uhlenbeck process with five adaptive peaks (insectivory, carnivory, sanguivory, nectarivory and frugivory).</p> <p>Conclusions</p> <p>The radiation of phyllostomid bats presented adaptive and non-adaptive components nested together through the time frame of the family's evolution. The first 10 My of the radiation were marked by strong phenotypic and ecological divergence among ancestors of modern lineages, whereas the remaining 20 My were marked by stasis around a number of probable adaptive peaks. A considerable amount of cladogenesis and speciation in this period is likely to be the result of non-adaptive allopatric divergence or adaptations to peaks within major dietary categories.</p

Magnetic resonance imaging in the assessment of meniscal anatomic variants and of the perimeniscal ligamentous anatomy: potential interpretation pitfalls

O conhecimento adequado das variações anatômicas meniscais e das estruturas perimeniscais é essencial para uma avaliação adequada dos exames de ressonância magnética do joelho, tanto no diagnóstico das lesões meniscais quanto para se evitar uma série de possíveis erros diagnósticos. Este artigo revê variações anatômicas que alteram o tamanho, a forma e a estabilidade meniscais e que incluem os vários tipos de menisco discoide, outras variações morfológicas meniscais menos frequentes e o ossículo meniscal. Também é revisada a anatomia de estruturas perimeniscais, principalmente ligamentares, que incluem os ligamentos meniscocapsulares, intermeniscais, meniscofemorais e extensões meniscoligamentares.The knowledge of meniscal anatomic variants and of the normal perimeniscal structures is essential to understand magnetic resonance imaging studies of the knee, both for the diagnosis of meniscal lesions and to avoid potential interpretation pitfalls. The present article reviews anatomic variants that change the size, shape and stability of the menisci, including the different types of discoid menisci, other less frequent meniscal malformations and the meniscal ossicle. Additionally, the anatomy of perimeniscal structures, particularly those including the meniscocapsular, intermeniscal, meniscofemoral ligaments and other menisco-ligamentous structures is reviewed

A experiência norte-americana com o seguro agrícola: lições ao Brasil?

Agricultural insurance is considered to be an effective to manage rural risks. Surprisingly, its adoption by farmers is very limited all over the world. An outstanding exception is the United States of America, country in which this instrument has achieved remarkable success. Nevertheless, the process of diffusion of agricultural insurance in the USA was slow and expensive. It has also required significant government intervention through a variety of complementary actions. In this context, countries willing to introduce this instrument among other agricultural policy tools, as it seems the case of Brazil, should proceed with caution. Agricultural insurance success has important pre-requisites and its general diffusion may amplify its problems. The analysis of the North American experience provides worthwhile lessons.rural risk management, agricultural insurance, North American agricultural policies., Agribusiness, Q18, Q12,