Influence Of Prey Size On Predation Success By Zelus Longipes L. (het., Reduviidae)

The effects of prey size on the predatory responses of the reduviid Zelus longipes were studied through laboratory tests using larvae of the noctuid moth Spodoptera frugiperda as preys. In tests with one caterpillar, larvae of three different weight classes were offered individually to the predator. The prey weight was positively correlated with relative weight gain by the predator, mean feeding time and discarded biomass, but not with the relative extraction rate (defined as the relative weight gain by the predator by feeding time). The different sizes of caterpillars were attacked with the same frequency, but the successful attacks were more frequent in small larvae. The median mass of successfully attacked larvae was also less than that of unsuccessfully attacked. In tests with three caterpillars, larvae of three weight classes were offered at the same time; small caterpillars were more often attacked and killed than the medium and large ones. 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Adubação nitrogenada no consórcio de milho com duas espécies de braquiária em sistema plantio direto

O objetivo deste trabalho foi avaliar a produtividade de grãos e de forragem do consórcio entre milho e espécies de braquiária (safras de 2008/2009 e 2009/2010), submetidos a doses de nitrogênio em cobertura, em sistema plantio direto. Utilizou-se o delineamento experimental inteiramente casualizado, com quatro repetições, em arranjo fatorial 2x5, com duas espécies de braquiária (Urochloa brizantha 'Xaraés' e U. ruziziensis) e cinco doses de N aplicadas em cobertura: 0, 50, 100, 150 e 200 kg ha‑1. Foram avaliados: leituras indiretas do teor foliar de clorofila (índice de clorofila Falker, ICF), teores de macronutrientes foliares, componentes da produção e produtividade de grãos do milho, e produtividade de matéria seca das forrageiras após o consórcio. Constatou-se que a espécie U. ruziziensis foi a mais competitiva com o milho em consórcio, o que proporcionou menores teores nutricionais e ICF nas duas safras analisadas. O crescimento vegetativo, os componentes da produção e a produtividade de grãos do milho não foram influenciados pelos consórcios. A adubação nitrogenada em cobertura aumenta linearmente o ICF, os teores de N, P e S, bem como os componentes da produção e a produtividade de grãos

Predation of Apiomerus pilipes (Fabricius) (Hemiptera, Reduviidae, Harpactorinae, Apiomerini) over Meliponinae bees (Hymenoptera, Apidae), in the State of Amazonas, Brazil

The present work shows the occurrence of an intense predatory activity on adults working Meliponinae bees (Hymenoptera, Apidae), by Apiomerus pilipes (Fabricius, 1787) (Hemiptera, Reduviidae, Harpactorinae, Apiomerini) at a meliponary in the Instituto Nacional de Pesquisas da Amazônia (INPA, Manaus), Amazonas State, Brazil.<br>O presente trabalho registra a ocorrência de intensa atividade predatória de Apiomerus pilipes (Fabricius, 1787) (Hemiptera, Reduviidae, Harpactorini, Apiomerini) sobre operárias adultas de meliponíneos (Hymenoptera, Apidae), no meliponário experimental do Instituto Nacional de Pesquisas da Amazônia (INPA, Manaus), Estado do Amazonas, Brasil. O meliponário se encontra num fragmento de vegetação secundária no próprio INPA