Fenologia e artrópodes de Copaifera langsdorffii Desf. no cerrado

There was evaluated the phenology and arthropods as well as the effect of weather on copaiba (Copaifera langsdorffii Desf.) (Leguminoseae). The emission of new leaves and inflorescences as well as the opening of them occurred in the rainy period. There were observed the higher diversity and abundance of insects, principally galling insects.

Seletividade de alguns agrotóxicos em uso na citricultura ao ácaro predador Neoseiulus californicus (McGregor) (Acari: Phytoseiidae)

This work was carried out to determine the residual toxicity of the main pesticides used in citrus, on Neoseiulus californicus (McGregor) under laboratory conditions. For this, it was used the residual contact bioassay. Citrus leaves of the variety Pêra were sprayed in a Potter tower. The residual action was evaluated at 2 hours and 1; 3; 5; 7; 10; 14 e 21 days after treatment. Ten adult females of N. californicus were transferred to each ring, together with an enough amount of Tetranychus urticae nymphs and adults to feed the predator. Mortality evaluations were performed at 72 hours after treatment. Bioassays indicate that the pesticides: acrinathrin, deltamethrin, dinocap, sulphur, fenpropathrin, fenbutatin oxide and propargite were innocuous to N. californicus. On the other hand, abamectin, azocyclotin e cyhexatin caused mortalities of 29.8; 32.0 e 34.1%, respectively, two hours after transference. Dicofol, pyridaben and chlorfenapyr were extremely toxic to the predator mite, causing 100% of mortality two hours after the application. This way, to this population of N. californicus, the releases can be performed safely 3 days after the application, except for cyhexatin (5 days), dicofol and pyridaben (14 days) and chlorfenapyr (21 days), without risk of significant adult mortality rates due to the application of pesticides.

Os Répteis do Município de São Paulo: Diversidade e ecologia da fauna pretérita e atual

The reptile fauna in the municipality of São Paulo is well sampled due to intensive collection in the last 100 years. In the present work we provide a checklist of reptile species in São Paulo municipality based on preserved specimens in scientific collections. The reptile fauna was also characterized by three ecological parameters: habitat use, substrate use, and diet. We recorded a total of 97 reptile species (two turtles, one crocodilian, 19 lizards, seven amphisbaenians, and 68 snakes). Approximately 70% of the lizards and 40% of the snakes are typical of forest habitats of the Serra do Mar mountain range. Other squamates are typical of open formations that occur mainly on inland Cerrado habitats. All turtles and the crocodilian are associated to riparian habitats. Approximately 63% of the lizards are predominantly terrestrial, and the remaining species are arboreal. Most species of snakes are terrestrial (38%) or subterranean/criptozoic (25%) whereas a smaller proportion are arboreal (18%) or aquatic (9%). Lizards feed upon arthropods. Almost 50% of the snake species are specialized or feed mainly upon anuran amphibians. Other important items consumed by snakes are mammals (24%), lizards (18%), subterranean vertebrates (10%), and invertebrates (earthworms, mollusks and arthropods; 15%). A total of 51 reptile species have not been recorded for the last six years. Probably many of these species are extinct in the region due the intense local urbanization and habitat loss. The survey of species collected in São Paulo municipality and received in the Instituto Butantan in recent years allowed the identification of 10 lizards at least 42 snake species already occurring in the region. The high species richness of the original fauna seems related to the geographic location of the municipality, in a contact zone between forested areas of the Atlantic Forest (ombrophilous forest) and open formations (savannas, high-altitude grassland). Thus, the original habitat composition probably allowed sympatry among different species pools typical of both open and forested formations. The extant snake fauna recorded in the last three years indicates a higher loss of the species in open formations when compared to the forested areas.

Presence and distribution of the endosymbiont Wolbachia among Solenopsis spp. (Hymenoptera: Formicidae) from Brazil and its evolutionary history

Wolbachia are intracellular bacteria that commonly infect arthropods. Its prevalence among ants of the genus Solenopsis is high. In the present study, the presence and distribution of these endosymbionts was examined among populations of Solenopsis spp. from Brazil. A phylogenetic analysis based on the wsp gene was conducted to infer the evolutionary history of Wolbachia infections within the populations surveyed. A high frequency of Wolbachia bacteria was observed among the genus Solenopsis, 51% of the colonies examined were infected. Incidence was higher in populations from southern Brazil. However, little genetic variability was found among different Wolbachia strains within supergroups A and B. Our findings also suggest that horizontal transmission events can occur through the social parasite S. daguerrei. © 2012 Elsevier Inc..

Fluazuron-induced morphophysiological changes in the cuticle formation and midgut of Rhipicephalus sanguineus Latreille, 1806 (Acari: Ixodidae) nymphs

The present study demonstrated the effects of the arthropod growth regulator, fluazuron (Acatak®), in the formation of the integument and digestive processes of Rhipicephalus sanguineus nymphs fed on rabbits treated with different doses of this chemical acaricide. For this, three different doses of fluazuron (20, 40, or 80 mg/kg) were applied pour on to the hosts (groups II, III, and IV), as well as distilled water to the control group. On the first day after treatment (24 h), the hosts were artificially infested with R. sanguineus nymphs. After full engorgement (7 days), the nymphs were removed, placed on labeled Petri dishes, and kept in biochemical oxygen demand incubator for 7 days. The engorged nymphs were then taken for morphological, histochemical, and histological analyses. The results showed the occurrence of cytological, morphohistological, and histochemical alterations in the integument and midgut of nymphs from all the different treated groups. These alterations occurred at cuticular level in the subdivisions of the cuticle, related to the size of the digestive cells, amount of accumulated blood elements, and digestive residues, as well as the presence of vacuoles in the cytoplasm of the digestive cells. Thus, this study demonstrated that fluazuron acts on the integument and midgut cells of R. sanguineus nymphs fed on treated rabbits and pointed out the possibility of the use of this chemical - which is more specific, less toxic, and less harmful to the environment and nontarget organisms - in the control of R. sanguineus, at least in the nymphal stage of its biological cycle. © 2012 Springer-Verlag.

Responses of aquatic insect functional diversity to landscape changes in Atlantic forest

The Atlantic Forest domain, one of the 25 world's hotspots for biodiversity, has experienced dramatic changes in its landscape. While the loss of species diversity is well documented, functional diversity has not received the same amount of attention. In this study, we evaluated functional diversity of insects in streams utilizing three indices: functional diversity (FD), functional dispersion (FDis), and functional divergence (FDiv), seeking to understand the roles of three predictor sets in explaining functional patterns: (1) bioclimatic and landscape variables; (2) spatial variables; and (3) local environmental variables. We determined the amount of variation in different measures of functional diversity that was explained by each predictor set and their interplays using variation partitioning. Our study showed that variation in functional diversity is better explained by a set of variables linked to different scales dependent on spatial structures, indicating the importance of landscape and mainly environmental variables in the functional organization of aquatic insect communities, and that the relative importance of predictor sets depends on the indices considered. Variation in FD was better explained by the interplay among the three predictor sets and by local environmental variables, whereas variation in FDis was better explained by spatial variables and by the interplay between environmental and spatial variables. Variation in FDiv was not significantly explained by any predictors. Our study adds more evidence on the harmful effects caused by landscape changes on biodiversity in the Atlantic Forest, suggesting that these effects also influence the functional organization of stream insect communities. © 2013 The Author(s) Journal compilation © 2013 by The Association for Tropical Biology and Conservation.

Preferência alimentar por insetos aquáticos em espécies de peixes de riacho tropical

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Estudo morfofisiológico dos ovários e do corpo gorduroso do carrapato-estrela Amblyomma cajennense Fabricius (1787) (Acari : Ixodidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Descrição morfo-histológica dos testículos de Amblyomma cajennense em jejum e alimentados

Os carrapatos são ectoparasitas hematófagos de grande importância epidemiológica, pois são vetores de muitos patógenos. Esses animais pertencem ao Filo Arthropoda, Classe Arachnida, Subclasse Acari, são classificados em três famílias: Ixodidae, Argasidae e Nutalliellidae, apresentam ampla distribuição geográfica e podem parasitar grande variedade de vertebrados, inclusive o homem. O carrapato da espécie Amblyomma cajennense, popularmente conhecido como carrapato-estrela, carrapato do cavalo ou rodoleiro, tem grande importância médica por ser vetor da bactéria Rickettsia rickettsii, causadora da febre maculosa brasileira (FMB), que pode levar o hospedeiro a óbito. Apesar das crescentes pesquisas com esses animais, ainda existem lacunas na literatura acerca de alguns de seus processos reprodutivos. Dessa forma, esse trabalho teve por objetivo estudar o desenvolvimento dos testículos dessa espécie por meio da descrição da morfologia e histologia dos testículos de indivíduos em jejum e alimentados, identificando a dinâmica do processo de espermatogênese e se a alimentação influencia nesse processo. Os resultados obtidos mostraram que os testículos são estruturas pares e tubulares arranjadas dorsolateralmente no opistossoma, sendo que a região proximal está conectada às vesículas seminais pelos ductos deferentes, semelhante ao observado em outras espécies de ixodídeos. Associado ao aparelho genital masculino encontra-se um complexo de glândulas acessórias multilobuladas. Foi constatado que a alimentação tem papel fundamental no desenvolvimento do sistema reprodutor, visto que nos indivíduos em jejum as vesículas seminais e o complexo de glândulas acessórias foram menores e menos desenvolvidos do que nos animais alimentados. Além disso, as espermátides alongadas, precursoras dos espermatozoides no trato reprodutor... (Resumo completo, clicar acesso eletrônico abaixo)

Hypersensitivity induced in dogs by nymphal extract of Amblyomma cajennense ticks (Acari:Ixodidae)

In general, hosts develop resistance to ticks after repeated infestations; nevertheless, several studies on naturally occurring host-tick interactions were unable to detect resistance of hosts to ticks even after repeated infestations. The purpose of this investigation was to study the type of cutaneous hypersensitivity to unfed nymphal extract of A. cajennense in dogs, which, unlike guinea pigs, do not develop resistance. A first, but no second, peak in skin reaction was observed, suggesting that cellular immunity is an important mechanism of resistance to ticks. This may partially explain why guinea pigs, but not dogs, develop resistance against ticks.

Development of resistance to nymphs of Amblyomma cajennense ticks (Acari : Ixodidae) in dogs

Ticks have long been regarded as constraints to humans and domestic animals, but hosts often develop resistance to ticks after repeated infestations. The purpose of this investigation was to study the possible acquisition of immunity in domestic dogs to nymphs of A. cajennense by determining the tick alimentary performance after successive controlled infestations. Mean engorged weight of nymphs was not significantly different among the three infestations; molting rate from nymph to adult ticks, and the percentage of nymph recovery were also very close in all infestations. These results are similar to those obtained in studies of the dog-adult Rhipicephalus sanguineus interface. It is concluded that domestic dogs do not develop resistance against nymphs of A. cajennense ticks.