The Amazonas‐trap: a new method for sampling plant‐inhabiting arthropod communities in tropical forest understory

Methods to quantify plant‐insect interactions in tropical forests may miss many important arthropods and can be time consuming and uneven in capture efficiency. We describe the Amazonas‐trap, a new method that rapidly envelops the target plant for sampling arthropods. We evaluated the efficiency of the Amazonas‐trap by comparing it with two commonly used sampling methods to collect arthropods from plants: the beating tray and manual collection. Samples were collected in 10 permanent plots, in the Ducke forest reserve, Manaus (Amazonas, Brazil). In each plot we sampled 18 plant individuals of Protium sp. (Burseraceae): six by a beating tray, six by manual collection, and six using the Amazonas‐trap. All insects were identified to the family level and those belonging to the order Hymenoptera were identified to the species and morphospecies level. The new method sampled more insect families and more Hymenoptera species than tree beating and manual collection. Of the 75 total families collected, 20 were sampled exclusively by the Amazonas‐trap, seven were only collected with a beating tray, and seven were sampled exclusively with manual collecting. A similar pattern was found for abundance: Amazonas‐trap sampled more individuals, followed by the beating tray and manual collection. Small and winged arthropods were more abundant in Amazonas‐trap, explaining the highest richness of Hymenoptera and insect families sampled with this method. The new method sampled more spiders, wood‐fungi feeders, sap suckers, omnivorous, parasitoids, and insect predators than the other methods, but was equally effective in sampling leaf‐feeders and ants. Amazonas‐trap was more time consuming in the field, but for all diversity parameters evaluated, the new method showed better performance for collecting invertebrates on plants.     

<Emphasis Type="Italic">Zornia decussata</Emphasis> (Leguminosae: Papilionoideae: Dalbergieae), a new species from the Amazon region of Venezuela

Zornia decussata, a new species from Venezuela, is described and illustrated. It belongs to sect. Anisophylla of subgen. Zornia and occurs in the Federal Territory of Amazonas, in the region of Rincones de Chacorro. The species is characterised mainly by its decussate bracteoles which lack an auricle, by the presence of a cataphyll between the stipules and by the delicate habit of the plant.     

Four new species of the Didymopanax group of <Emphasis Type="Italic">Schefflera</Emphasis> (Araliaceae) from the Brazilian Amazon

Four new species of the Didymopanax group of Neotropical Schefflera (Araliaceae) from the Brazilian Amazon are here described and illustrated. Two of these are mainly known from the surroundings of Manaus, Amazonas state (Schefflera ciliatifolia and Schefflera umbrosa). The first is distinguished by its ciliate leaflets, while the second is characterized by leaflets varying in shape from trilobed to entire. Schefflera plurifolia is known only from southern Amazonian forests, and is remarkable in its pinnately-compound leaflets. Schefflera dichotoma, only known from the type collected on “campinarana” forests from Upper Rio Negro, at the municipality of São Gabriel da Cachoeira (Amazonas), is characterized by dichotomously branching inflorescences. Comments on the geographic distribution and ecology of the new species are provided, as well as an identification key to the species of the Didymopanax group found in Brazilian Amazonian rainforests and savannas.     

Ticks (Acari: Ixodidae) of the state of Amazonas,Brazil

The tick fauna of Brazil is currently composed by 72 species. The state of Amazonas is the largest of Brazil, with an area of ≈ 19% of the Brazilian land. Besides its vast geographic area, only 19 tick species have been reported for Amazonas. Herein, lots containing ticks from the state of Amazonas were examined in three major tick collections from Brazil. A total of 5933 tick specimens were examined and recorded, comprising 2693 males, 1247 females, 1509 nymphs, and 484 larvae. These ticks were identified into the following 22 species: Amblyomma cajennense sensu lato, Amblyomma calcaratum, Amblyomma coelebs, Amblyomma dissimile, Amblyomma dubitatum, Amblyomma geayi, Amblyomma goeldii, Amblyomma humerale, Amblyomma latepunctatun, Amblyomma longirostre, Amblyomma naponense, Amblyomma oblongoguttatum, Amblyomma ovale, Amblyomma rotundatum, Amblyomma scalpturatum, Amblyomma varium, Dermacentor nitens, Haemaphysalis juxtakochi, Ixodes cf. Ixodes fuscipes, Ixodes luciae, Rhipicephalus microplus, Rhipicephalus sanguineus sensu lato. Ticks were collected from 17 (27.4%) out of the 62 municipalities that currently compose the state of Amazonas. The following four species are reported for the first time in the state of Amazonas: A. coelebs, A. dubitatum, H. juxtakochi, and Ixodes cf. I. fuscipes. The only tick species previously reported for Amazonas and not found in the present study is Amblyomma parvum. This study provides a great expansion of geographical and host records of ticks for the state of Amazonas, which is now considered to have a tick fauna composed by 23 species. It is noteworthy that we report 1391 Amblyomma nymphs that were identified to 13 different species.     

<Emphasis Type="Italic">Myrcia incompleta</Emphasis> (Myrtaceae), a new species from Amazonian Brazil

Myrcia incompleta, from the northern Brazilian states of Amazonas and Rondônia, is described and illustrated. This species is apparently related to Calyptranthes paniculata and C. speciosa, from which it is distinguished mainly by its narrower leaves with midvein strongly raised adaxially and shorter, pauciflorous inflorescences. Conservation status for the species is proposed.     

A new <Emphasis Type="Italic">Zamia</Emphasis> (Zamiaceae) from Colombia

Zamia lindosensis, a species of cycad from sandy soils of Amazonas, Colombia, is described and illustrated. It is compared to Zamia amazonum, which has similar habitat requirements, petiole morphology and prickles, leaflet margins, and strobili but with very narrow leaflets.     

<Emphasis Type="Italic">Duranta neblinensis</Emphasis> (Verbenaceae,Duranteae): A new species from Sierra de la Neblina,Amazonas state,Venezuela

Duranta neblinensis, from Sierra de la Neblina, Amazonas state, Venezuela is described, illustrated, and its morphological relationships with allied species are discussed. This new species is similar to D. obtusifolia, but it differs by its stout spines; pubescent petioles and leaves; apiculate calyx lobes; and fruits with an open, slender, curved rostrum . An updated key to the six Venezuelan species of Duranta is presented, and phytogeographic information about Sierra de la Neblina is provided.     

Length–weight relationships of four freshwater ornamental fish species from the Brazilian Negro River basin

The present work reports the length–weight relationships (LWR) for four ornamental fish species from the middle Negro River basin, Amazonas, Brazil. The r² value ranged from 0.810 to 0.941 and values of b varied from 2.346 to 3.442. These results represent the first reference on LWR for all four species, based on FishBase.     

Molecular analysis reveals hidden diversity in <Emphasis Type="Italic">Zungaro</Emphasis> (Siluriformes: Pimelodidade): a genus of giant South American catfish

The genus Zungaro contains some of the largest catfish in South America. Two valid species are currently recognized: Zungaro jahu, inhabiting the Paraná and Paraguay basins, and Zungaro zungaro, occurring in the Amazonas and Orinoco basins. Analysing Zungaro specimens from the Amazonas, Orinoco, Paraguay and Paraná basins, based on the sequencing of COI and D-loop, we found at least three MOTUs, indicating the existence of hidden diversity within this fish group. Considering the ecological and economic values of this fish, our results are surely welcomed for its conservation, disclosing new findings on its diversity and pointing out the necessity for a detailed taxonomic revision.     

First report of Lutzomyia araracuarensis (Morales & Minter) (Diptera: Psychodidae) in Brazil

A male of Lutzomyia araracuarensis (Morales & Minter) and possibly six females of this same species were found in the northeastern area of Manacapuru county, Amazonas State. Samples were collected using light traps CDC, from April 2003 to June 2004.     

Length–Weight relationships of 23 fish species from floodplain ecosystems of the Andean Amazon piedmont,Peru

Length–weight relationships (LWRs) for 23 freshwater fish species from the Andean Amazon piedmont in Peru are presented in this study. Fishes were captured between 2009 and 2010 on lagoons from three basins; Amazonas (Ampiyacu and Apayacu) and Ucayali (Pachitea) using gillnets. In this study, new LWRs are reported for 20 species of 23 species analyzed. The study provides new information on less‐studied species and can serve as a basis for management of fisheries and conservation of this area.     

Length‐weight relationships of three freshwater fish species from the Cujubim Sustainable Development Reserve,Amazonas, Brazil

Length–weight relationships (LWR) were provided for three fish species from Cujubim Sustainable Development Reserve, drainages of the Jutaí River Basin, a tributary of the Solimões River, part of the Central Amazon Biodiversity Corridor, Amazonas, Region North of Brazil. Specimens were collected in March 2006 using gill nets with mesh sizes range between 2 and 18 cm. The LWRs for all species are provided by the first time, and two new maximum length are recorded.     

The Casiquiare river acts as a corridor between the Amazonas and Orinoco river basins: biogeographic analysis of the genus Cichla

The Casiquiare River is a unique biogeographic corridor between the Orinoco and Amazonas basins. We investigated the importance of this connection for Neotropical fishes using peacock cichlids (Cichla spp.) as a model system. We tested whether the Casiquiare provides a conduit for gene flow between contemporary populations, and investigated the origin of biogeographic distributions that span the Casiquiare. Using sequences from the mitochondrial control region of three focal species (C. temensis, C. monoculus, and C. orinocensis) whose distributions include the Amazonas, Orinoco, and Casiquiare, we constructed maximum likelihood phylograms of haplotypes and analyzed the populations under an isolation‐with‐migration coalescent model. Our analyses suggest that populations of all three species have experienced some degree of gene flow via the Casiquiare. We also generated a mitochondrial genealogy of all Cichla species using >2000 bp and performed a dispersal‐vicariance analysis (DIVA) to reconstruct the historical biogeography of the genus. This analysis, when combined with the intraspecific results, supports two instances of dispersal from the Amazonas to the Orinoco. Thus, our results support the idea that the Casiquiare connection is important across temporal scales, facilitating both gene flow and the dispersal and range expansion of species.