Fragmentation of a Neotropical migratory fish population by a century-old dam

Loss of connectivity in impounded rivers is among the impacts imposed by dams, and mitigation measures such as fish passages might not accomplish their purpose of reestablishing an efficient bi-directional gene flow in the fish populations affected. As a consequence, fish populations remain fragmented, and a new interpopulational structure may develop, with increased risk of reduced genetic diversity and stochastic extinction. In order to evaluate the effects of the Gavio Peixoto Dam, which was constructed almost a century ago on the Jacar,-Gua double dagger u River in the Upper Parana River basin, Brazil, a comparative morphometric study was undertaken on the populations of the Neotropical migratory characid fish Salminus hilarii living up- and downstream of this dam. Population dynamics, spatial segregation, and habitat use by different age classes were monitored for 2 years. We found that segregation caused by the dam and long periods with no efficient connection by fish passages have led to fragmentation and interpopulational structuring of S. hilarii, as revealed by canonical variable analysis of morphometric features. The fish populations occupying the up- and downstream sections have succeeded in performing short-distance reproductive migrations in the main river and tributaries, have found suitable habitats for completing their life cycle, and have been able to maintain distinct small-sized populations so far.

Review of the Neotropical species of Nervijuncta Marshall, 1896 (Diptera, Ditomyiidae)

Both known Neotropical species of Nervijuncta - N. conjuncta (Freeman) and N. laffooni Lane - are redescribed and the male terminalia illustrated in detail. Specimens of N. laffooni, previously known only from the type-locality (Sao Paulo, Brazil), are reported from Nova Teutonia, and Urubici, both in the State of Santa Catarina, Brazil. The females of both Neotropical species of the genus are described in detail and the genitalia illustrated for the first time. These redescriptions provide further information on the position of these two species within the genus.

Neotropical Meliponini: the genus Celetrigona Moure (Hymenoptera: Apidae, Apinae)

Three new species of Celetrigona are described: C. euclydiana sp. nov., from Acre, Brazil, C. hirsuticornis sp. nov., from Rondonia, Brazil and C. manauara sp. nov., from the northern Amazon. Additional geographic records are provided for C. longicornis (Friese, 1903), the only previously known species; its nest and the male are described and illustrated for the first time. Diagnosis and an identification key for species are provided, which are distinguished by the pattern of pilosity on the antenna.

Nest site selection by a neotropical swarm-founding wasp: seasonal alternation of nest orientation

Nest orientation in social insects has been intensively studied in warmer and cooler climates, particularly in the northern hemisphere. Previous studies have consistently shown that species subjected to these climatic conditions prefer to select mostly southern locations where the nests can gain direct sunlight. However, very little is known on nest orientation in tropical and subtropical social insects. We studied nest orientations initiated by swarms throughout a year in a Brazilian swarm-founding wasp, Polybia paulista von Ihering (Hymenoptera: Polistinae). Swarms selected various orientations as nest sites, but there was a particular trend in that swarms in the winter period (May-August) preferred to build northward-facing nests. This preference is opposite from that of social wasps observed in the northern hemisphere. Colonies of this species can potentially last for many years with continuous nesting, but nesting activities of colonies during the winter are severely limited due to cool temperature and a shortened day length. Northward-facing nests are warmer through the gain of direct solar heat during the winter period; consequently, choosing northward-facing sites may be advantageous for swarms in terms of a shortened brood development and shortened time needed to increase metabolic rates during warm-up for flight.

A new genus of net-winged beetles from Neotropical Region (Coleoptera: Lycidae)

The new genus Brasilycus is proposed within the tribe Calopterini. Following new species are described in the genus: Brasilycus capixabus n. sp., B. rondonensis n. sp., and B. bolivianus n. sp., all from South America. Illustrations of diagnostic characters and key to Brasilycus are given.

A revision of Gasteruption Latreille (Hymenoptera: Gasteruptiidae) in the Neotropical Region

The Neotropical species of Gasteruption Latreille are revised, described, diagnosed, and illustrated; a key for females is provided. Twenty six valid species are recognized, thirteen of which are described as new: G. amputatum Townes, G. barnstoni (Westwood), G. bertae n. sp., G. bispinosum Kieffer, G. brachychaetum Schrottky, G. brandaoi n. sp., G. brasiliense (Blanchard), G. floridanum (Bradley), G. glauciae n. sp., G. guildingi (Westwood), G. hansoni n. sp., G. helenae n. sp., G. huberi n. sp., G. kaweahense (Bradley), G. lianae n. sp., G. loiaconoae n. sp., G. masneri n. sp., G. oliveirai n. sp., G. parvum Schrottky, G. rafaeli n. sp., G. sartor Schletterer, G. smithi n. sp., G. tenue Kieffer, G. townesi (Alayo), G. visaliae (Bradley), and G. wahli n. sp. The following new synonymies are proposed: G. maculicorne Cameron, G. macroderum Schletterer, and G. zapotecum Schletterer with G. barnstoni; G. bihamatum Kieffer, G. fallens Kieffer, G. fiebrigi Schrottky, G. leptodomum Kieffer, G. montivagum Kieffer, and G. strandi Kieffer with G. bispinosum; G. annulitarse Schrottky, G. brasiliae Kieffer, G. gracillimum (Schletterer), G. longicauda Kieffer, G. petroselini Schrottky, G. subtropicale Schrottky and G. torridum (Bradley) with G. brasiliense; G. rufipectus (Westwood) with G. guildingi; G. angustatum (Kieffer) with G. kaweahense; G. horni Brethes with G. parvum. The following taxa are considered as species inquirendae: G. albitarse Schletterer, G. austini Jennings and Smith, G. subcoriaceum Kieffer n. stat., and G. tenuicolle Schletterer. As well, G rubrum Taschenberg is synonymized with Pseudofoenus infumatus (Schletterer). In addition, G. tenue Pasteels, 1957a from Australia is a junior homonym of G. tenue Kieffer, 1922 and is renamed G. pasteelsi n. name.

Ant visitation to extrafloral nectaries decreases herbivory and increases fruit set in Chamaecrista debilis (Fabaceae) in a Neotropical savanna

Studies of ant-plant relationships elucidate how top-down effects of the third trophic level can affect the biomass, richness, and/or species composition of plants. Although widespread in the neotropics, few studies have so far examined the direct effects of ants on plant fitness. Here, through experimental manipulation (ant-exclusion) under natural conditions, we examined the effect of ant visitation to extrafloral nectaries on leaf herbivory and fruit set in Chamaecrista debilis in the Brazilian savanna. As opposed to other Chamaecrista species, our results showed that visiting ants (15 species) significantly reduce herbivory and increase fruit set by more than 50% compared to plants from which ants were excluded. This mutualistic system is facultative in nature, and corroborates the potential beneficial role of exudate-feeding ants as anti-herbivore agents of tropical plants. (C) 2010 Elsevier GmbH. All rights reserved.

What the reasons for no inbreeding and high genetic diversity of the neotropical fig tree Ficus arpazusa ?

Ficus arpazusa Casaretto is a fig tree native to the Atlantic Rain Forest sensu lato. High levels of genetic diversity and no inbreeding were observed in Ficus arpazusa. This genetic pattern is due to the action of its pollinator, Pegoscapus sp., which disperses pollen an estimated distance of 5.6 km, and of Ficus arpazusa`s mating system which, in the study area, is allogamous. This study highlights the importance of adding both ecological and genetic data into population studies, allowing a better understanding of evolutionary processes and in turn increasing the efficacy of forest management and revegetation projects, as well as species conservation.

Generic classification for the Gasteruptiinae (Hymenoptera: Gasteruptiidae) based on a cladistic analysis, with the description of two new Neotropical genera and the revalidation of Plutofoenus Kieffer

Gasteruptiinae is the largest Gasteruptiidae subfamily, with circa 400 species that have been grouped into the worldwide Gasteruption Latreille. Based on a cladistic analysis with 43 morphological characters, 40 ingroup taxa representing all biogeographic regions, and seven outgroups (four Hyptiogastrinae, two Aulacidae and one Evaniidae), I confirm the monophyly of Gasteruptiinae and Gasteruption and recognize three exclusively Neotropical small genera: Plutofoenus Kieffer (revalidated) (southern South America), Spinolafoenus Macedo n. gen. (Chile) and Trilobitofoenus Macedo n. gen. (Central and South America). Gasteruption, supported by four synapomorphies, remains the most speciose genus in the subfamily. The four Gasteruptiinae genera are keyed and described. Seven species are keyed and described or redescribed: Plutofoenus chaeturus (Schletterer) n. comb., P. edwardsi Turner, P. paraguayensis (Schrottky), Spinolafoenus ruficornis (Spinola) n. comb., Trilobitofoenus alvarengai Macedo n. sp., T. plaumanni Macedo n. sp. and T. sericeus (Cameron) n. comb. (lectotype designated).

The Neotropical genus Stibadocerina Alexander and its phylogenetic relationship to other Stibadocerinae genera: further evidence of an ancestral trans-Pacific biota (Diptera: Cylindrotomidae)

Stibadocerina Alexander, a monotypic genus, includes the only known Neotropical species of the family Cylindrotomidae, S. chilensis Alexander, 1929, from South Central Chile (ca. 36 degrees 50`S-42 degrees 17`S). In this paper, Stibadocerina chilensis is redescribed and illustrated in detail. A study of wing-vein homology in the subfamily Stibadocerinae is provided, to identify the components of the reduced radial sector in Stibadocerina and related taxa. The proposed hypotheses of wing-vein homology are tested, and the systematic position of Stibadocerina is assessed through a cladistic analysis of 13 characters of the male imago, scored for exemplar species of the four genera included in the Stibadocerinae. A single most parsimonious tree supports the monophyly of the Stibadocerinae and the following relationships among its included genera: Stibadocerodes [Stibadocera (Stibadocerella + Stibadocerina)]. The subfamily includes one example of a vicariant distribution with a sister-group relationship between South Central Chilean and East Asian taxa, and supports a biogeographical interpretation of an ancestral trans-Pacific biota.

Evaluating the use of predatory insects as bioindicators of metals contamination due to sugarcane cultivation in neotropical streams

Streams located in areas of sugarcane cultivation receive high concentrations of metal ions from soils of the adjacent areas causing accumulation of metals in the aquatic sediment. This impact results in environmental problems and leads to bioaccumulation of metal ions in aquatic organisms. In the present study, metal concentrations in different predatory insects were studied in streams near sugarcane cultivation and compared to reference sites. Possible utilisation of predatory insects as bioindicators of metal contamination due to sugarcane cultivation from 13 neotropical streams was evaluated. Ion concentrations of Al, Cd, Cr, Cu, Zn, Fe, and Mn in adult Belostomatidae (Hemiptera) and in larvae of Libellulidae (Odonata) were analysed. Nine streams are located in areas with sugarcane cultivation, without riparian vegetation (classified as impacted area) and four streams were located in forested areas (reference sites). Metal concentrations in insects were higher near sugarcane cultivations than in control sites. Cluster analysis, complemented by an ANOSIM test, clearly showed that these insect groups are good potential bioindicators of metal contamination in streams located in areas with sugarcane cultivation and can be used in monitoring programmes. We also conclude that Libellulidae appeared to accumulate higher concentrations of metals than Belostomatidae.

Description of the immature stages of Notalina morsei Holzenthal, 1986 (Trichoptera : Leptoceridae) and an updated key to larvae of Neotropical Leptoceridae genera

The endemic Neotropical long-horned caddisfly subgenus Notalina (Neonotalina) Holzenthal contains nine described species, but its immature stages are unknown. In this paper the larvae and pupae of Notalina morsei Holzenthal 1986 from southeastern Brazil are described and illustrated. Larvae of the subgenus are easily recognized from other Neotropical leptocerids by the following characters: ventral apotome which is broad anteriorly and narrow posteriorly; the metanotum with three sclerites; the metasternum bearing 10-12 setae; the gill arrangement, usually including ventral and dorsal filaments from abdominal segments II to VI; and abdominal tergite IX with 6 long and 4 short setae. An updated key to known larvae of Neotropical Leptoceridae genera is provided.

Species richness, abundance, and body size relationships from a neotropical chironomid assemblage: Looking for patterns

We investigated two of the most studied relationships in the macroecological research program (species richness vs. body size and abundance vs. body size) of a local chironomid assemblage from southeastern Brazil. Although numerous Studies have examined these relationships, few have investigated how they vary at different temporal scales. We used data from a forested stream to document and examine these patterns at monthly intervals. Both the species body size distribution and the abundance-body size relationship varied temporally. In some months the body size distribution was skewed to the right. whereas in others it approached normality. We Found both linear relationships (with different values of slopes). and a polygonal pattern in the abundance-body size relationship. This temporal variation was not related to environmental variables. Our results suggest that body size relationships are temporally instable properties of this chironomid assemblage. (C) 2007 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.

Detection of Bartonella spp. in neotropical felids and evaluation of risk factors and hematological abnormalities associated with infection

Although antibodies to Bartonella henselae have been described in all neotropical felid species, DNA has been detected in only one species, Leopard us wiedii. The aim of this study was to determine whether DNA of Bartonella spp. could be detected in blood of other captive neotropical felids and evaluate risk factors and hematological findings associated with infection. Blood samples were collected from 57 small felids, including 1 Leopard us geoffroyi, 17 L wiedii, 22 Leopardus tigrinus, 14 Leopardus pardalis, and 3 Puma yagouaroundi; 10 blood samples from Panthera onca were retrieved from blood banks. Complete blood counts were performed on blood samples from small felids, while all samples were evaluated by PCR. DNA extraction was confirmed by amplification of the cat GAPDH gene. Bartonella spp. were assessed by amplifying a fragment of their 16S-23S rRNA intergenic spacer region; PCR products were purified and sequenced. For the small neotropical felids, risk factors [origin (wild-caught or zoo-born), gender, felid species, and flea exposure) were evaluated using exact multiple logistic regression. Hematological findings (anemia, polycythemia/hyperproteinemia, leukocytosis and leukopenia) were tested for association with infection using Fisher`s exact test. The 635 bp product amplified from 10 samples (10/67 = 14.92%) was identified as B. henselae by sequencing. Small neotropical felid males were more likely to be positive than females (95% CI = 0.00-0.451, p = 0.0028), however other analyzed variables were not considered risk factors (p > 0.05). Hematological abnormalities were not associated with infection (p > 0.05). This is the first report documenting B. henselae detection by PCR in several species of neotropical felids. (C) 2009 Elsevier B.V. All rights reserved.

SURVEY OF FELINE LEUKEMIA VIRUS AND FELINE CORONAVIRUSES IN CAPTIVE NEOTROPICAL WILD FELIDS FROM SOUTHERN BRAZIL

A total of 57 captive neotropical felids (one Leopardus geoffroyi, 14 Leopardus pardalis, 17 Leopardus wiedii, 22 Leopardus tigrinus, and three Puma yagouaroundi) from the Itaipu Binacional Wildlife Research Center (Refugio Bela Vista, Southern Brazil) were anesthetized for blood collection. Feces samples were available for 44 animals, including one L. geoffroyi, eight L. pardalis, 14 L. wiedii, 20 L. tigrinus, and one P. yagouaroundi. Total DNA and RNA were extracted from blood and feces, respectively, using commercial kits. Blood DNA samples were evaluated by polymerase chain reaction (PCR) for feline leukemia virus (FeLV) proviral DNA, whereas reverse transcriptase-PCR was run on fecal samples for detection of coronavirus RNA. None of the samples were positive for coronaviruses. A male L. pardalis and a female L. tigrinus were positive for FeLV proviral DNA, and identities of PCR products were confirmed by sequencing. This is the first evidence of FeLV proviral DNA in these species in Southern Brazil.