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Este artigo relata a primeira ocorrência do parasitoide Entedononecremnus bimaculatus Hansson & LaSalle (Hymenoptera: Eulophidae) no Brasil. O inseto foi encontrado parasitando ninfas de mosca-branca, Aleurodicus sp. (Hemiptera: Aleyrodidae), em pimenta-longa, Piper hispidinervum C. DC., no Município de Rio Branco, AC. O parasitismo foi de 27,2%, com a coleta de 22 exemplares do parasitoide.

This paper reports the first occurrence of the parasitoid Entedononecremnus bimaculatus Hansson & LaSalle (Hymenoptera: Eulophidae) in Brazil. The insect was recorded on whitefly nymphs of Aleurodicus sp. (Hemiptera: Aleyrodidae), on Piper hispidinervum C. DC., in the county of Rio Branco, state of Acre, Brazil. The parasitism was 27.2%, with 22 specimens collected.

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Schistosomiasis is one of the world’s greatly neglected tropical diseases, and its control is largely dependenton a single drug, praziquantel. Here, we report the in vitro effect of piplartine, an amide isolated from Piper tuberculatum (Piperaceae), on Schistosoma mansoni adult worms. A piplartine concentrationof 15.8 lM reduced the motor activity of worms and caused their death within 24 h in a RPMI 1640 medium.Similarly, the highest sub-lethal concentration of piplartine (6.3 lM) caused a 75% reduction in eggproduction in spite of coupling. Additionally, piplartine induced morphological changes on the tegument,and a quantitative analysis carried out by confocal microscopy revealed an extensive tegumental destructionand damage in the tubercles. This damage was dose-dependent in the range of 15.8–630.2 lM. At doses higher than 157.6 lM, piplartine induced morphological changes in the oral and ventral sucker regions of the worms. It is the first time that the schistosomicidal activity has been reported forpiplartine.

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The stems of some myrmecophytes in Piper are used as domatia by resident ant colonies. Hollow, ant-occupied stems were previously known only in four species of southern Central American Piper, all members of Section Macrostachys. Here we present two additional, unrelated, hollow-stemmed myrmecophytes from Ecuador: P. immutatum and P. pterocladum (members of sections Radula and Peltobryon, respectively). Although similar superficially, stem cavities of the Ecuadorian Piper species differ morphologically and developmentally from those of Central American taxa. The stem cavities of P. immutatum, and possibly P. pterocladum, are formed during stem development, and begin forming only a few millimeters behind the apical meristem. This mode of cavity formation differs markedly from myrmecophytes in section Macrostachys, where the stems remain solid unless excavated by the specialized ant partner Pheidole bicornis. The stems of P. immutatum and P. pterocladum do not produce wound-response tissue around the cavity, unlike the stems in section Macrostachys. The entrance holes in stems of P. immutatum are formed through apoptotic processes and are located at each node below the petiole, whereas those in section Macrostachys are excavated by the ants in the leaf axil. This study documents convergent evolution of ant-plant associations in Piper, and emphasizes the need for careful comparison of apparently homologous, ant-associated structures in specialized myrmecophytes.

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Piperaceae species have been placed among the basal angiosperm and are adapted to a variety of habitats including moist forests, secondary vegetation and dry high lands. The major anatomical/morphology features are of small trees, vines, and shrubs for Piper species, while the epiphytic and succulent characteristics are predominant forms among Peperomia species. Their secondary chemistry can be mostly represented by amides, phenylpropanoids/lignoids, and chromenes in addition to a phletoria of biosynthetically mixed-origin secondary compounds. Although several amides and lignans are known as insecticides, several phytophagous insects, among which some considered pests of economic importance, have been observed feeding vigorously on Piperaceae species. Herein we describe the feeding preferences of fourteen phytophagous species of Coleoptera, Lepidoptera and Hemiptera over approximately fifty Piperaceae species observed in São Paulo, SP, Brazil, in a long-term basis.

As espécies de Piperaceae têm sido posicionadas entre as angiospermas basais e são frequentemente encontradas em habitats diversificados que incluem matas ciliares, vegetação secundária e campos rupestres. As espécies de Piper possuem hábitos de plantas herbáceas, arboretos e trepadeiras enquanto que, no caso de Peperomia, é freqüente o hábito de epífitas e suculentas. As classes de metabólitos secundários que caracterizam espécies de Piperaceae são amidas, fenilpropanóides/lignóides e cromenos, além de diversos outros de origem biossintética mista de menor representatividade. Apesar de muitos desses possuírem atividades inseticidas, diversos insetos fitófagos, alguns considerados pragas de importância econômica, foram observados alimentando-se de espécies de Piperaceae. Neste trabalho são relatadas as preferências alimentares de quatorze espécies fitófagas de Coleoptera, Lepidoptera e Hemiptera sobre aproximadamente cinqüenta espécies de Piperaceae observadas em São Paulo, SP, Brasil, durante um período de quatro anos.

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The role of phytophagous insects in ecosystem nutrient cycling remains poorly understood. By altering the flow of litterfall nutrients from the canopy to the forest floor, herbivores may influence key ecosystem processes. We manipulated levels of herbivory in a lower montane tropical rainforest of Puerto Rico using the common herbivore, Lamponius portoricensis (Phasmatidea), on a prevalent understory plant, Piper glabrescens (Piperaceae), and measured the effects on nutrient input to the forest floor and on rates of litter decomposition. Four treatment levels of herbivory generated a full range of leaf area removal, from plants experiencing no herbivory to plants that were completely defoliated (>4,000 cm(2) leaf area removed during the 76-day study duration). A significant (P<0.05) positive regression was found between all measures of herbivory (total leaf area removed, greenfall production, and frass-related inputs) and the concentration of NO (3) (-) in ion exchange resin bags located in the litter layer. No significant relationship was found between any of the herbivory components and resin bag concentrations of NH (4) (+) or PO (4) (-) . Rates of litter decay were significantly affected by frass-related herbivore inputs. A marginally significant negative relationship was also found between the litter mass remaining at 47 days and total leaf area removed. This study demonstrated a modest, but direct relationship between herbivory and both litter decomposition and NO (3) (-) transfer to the forest floor. These results suggest that insect herbivores can influence forest floor nutrient dynamics and thus merit further consideration in discussions on ecosystem nutrient dynamics.

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