RESUMO
Human presence and activity in tropical forest is thought to exert top-down regulation over the various 'green-world' pathways of plant-based foodwebs. However, these effects have never been explored for the 'brown-world' pathways of fecal-detritus webs. The strong effects of humans on tropical game mammals are likely to indirectly influence fecal detritivores (including Scarabaeine dung beetles), with subsequent indirect impacts on detrivore-mediated and plant-facilitating detrital processes. Across a 380-km gradient of human influence in the western Brazilian Amazon, we conducted the first landscape-level assessment of human-induced cascade effects on the fecal detritus pathway, by coupling data on human impact, game mammal and detritivore community structure, and rate measurements of a key detritus process (i.e. dung beetle-mediated secondary seed dispersal). We found evidence that human impact indirectly influences both the diversity and biomass of fecal detritivores, but not detritivore-mediated processes. Cascade strength varied across detritivore groups defined by species' traits. We found smaller-bodied dung beetles were at higher risk of local decline in areas of human presence, and that body size was a better predictor of cascade structure than fecal resource manipulation strategy. Cascade strength was also stronger in upland, unflooded forests, than in seasonally flooded forests. Our results suggest that the impact of human activity in tropical forest on fecal-detritus food web structure is mediated by both species' traits and habitat type. Further research will be required to determine the conditions under which these cascade effects influence fecal-detritus web function.
Assuntos
Tamanho Corporal/fisiologia , Besouros/fisiologia , Fezes , Cadeia Alimentar , Mamíferos/fisiologia , Animais , Biodiversidade , Brasil , Defecação , Ecossistema , Humanos , Dinâmica Populacional , Árvores , Clima TropicalRESUMO
First record of necrophagy by Scybalocanthon nigriceps Harold (Coleoptera, Scarabaeidae, Scarabaeinae). The S. nigriceps specimen was observed making small cuts and removing portions of the carcass of a frog Haddadus binotatus (Spix) in February 24, 2011, in Serra do Japi, São Paulo State, Brazil. This note presents another record of necrophagy for Scybalocanthon.
Primeiro relato de necrofagia por Scybalocanthon nigriceps Harold (Coleoptera, Scarabaeidae, Scarabaeinae). O espécime de S. nigriceps foi observado fazendo pequenos cortes e removendo porções da carcaça da rã Haddadus binotatus (Spix) em 24 de fevereiro de 2011 na Serra do Japi, Estado de São Paulo, Brasil. Esta nota apresenta mais um registro de negrofagia para Scybalocanthon.
RESUMO
The Scarabaeidae s. str. species collected at the regions of Doce River Delta and Suruaca Valley, Linhares Municipality, Espírito Santo, Brazil, are listed and commented. Twenty-four species have been collected, belonging to 13 genera in 6 tribes (Ateuchini, Canthonini, Phanaeini, Eurysternini, Onthophagini and Coprini).
RESUMO
The Scarabaeidae s. str. species collected at the regions of Doce River Delta and Suruaca Valley, Linhares Municipality, Espírito Santo, Brazil, are listed and commented. Twenty-four species have been collected, belonging to 13 genera in 6 tribes (Ateuchini, Canthonini, Phanaeini, Eurysternini, Onthophagini and Coprini).
RESUMO
A escassez de trabalhos a respeito da fauna de vespas do figo no Brasil motivou o presente estudo, que teve como objetivo apresentar os gêneros de Agaonidae (Hymenoptera) associados a sicônios de Ficus mexiae Standl. O estudo foi conduzido em um espécime nativo de F. mexiae, situado no câmpus da Universidade Federal de Lavras, Lavras, Minas Gerais. Foram encontrados quatro gêneros de Agaonidae, pertencentes a três subfamílias, ocorrendo no interior dos sicônios. As vespas dos gêneros Aepocerus, Heterandrium e Idarnes não são polinizadoras e as outras duas espécies, pertencentes ao gênero Pegoscapus Cameron, são vespas polinizadoras. As espécies polinizadoras foram encontradas co-ocorrendo em vários sicônios da mesma figueira.
The paucity of information on the fauna of the fig wasp in Brazil motivated the present research work, which intended to report the genera of Agaonidae that occur associated to syconia of Ficus mexiae Standl in this country. The study was conducted on one individual F. mexiae plant, located at the campus of the Federal University of Lavras, Lavras County, State of Minas Gerais, Brazil. Four different genera of Agaonidae, from three different subfamilies were found occurring inside the syconia. Three species from the genera Aepocerus, Heterandrium and Idarnes were non-pollinator wasps, while the other two were pollinating wasps of the genus Pegoscapus. The pollinator species were found co-occurring in many syconia of the same fig tree
RESUMO
Prosierola rotunda sp. nov. from northern Brazil is described and illustrated. Additional specimens of P. lata (Cameron, 1888) were examined with species variation analyzed and new distribution data are added.
É descrita e ilustrada Prosierola rotunda sp. nov. do norte do Brasil. Foram examinados novos espécimes de P. lata (Cameron, 1888), com a análise das variações morfológicas e inclusão novos dados de distribuição.
RESUMO
Prosierola rotunda sp. nov. from northern Brazil is described and illustrated. Additional specimens of P. lata (Cameron, 1888) were examined with species variation analyzed and new distribution data are added.
É descrita e ilustrada Prosierola rotunda sp. nov. do norte do Brasil. Foram examinados novos espécimes de P. lata (Cameron, 1888), com a análise das variações morfológicas e inclusão novos dados de distribuição.