Atratividade de Bucephalogonia xanthophis (Cicadellidae) por voláteis de seu hospedeiro atural Vernonia condensata (Asteraceae)

Plant volatiles are important cues for the orientation of herbivorous insects. It is possible that these compounds indicate whether the plant is suitable for feeding and larval development, or for mating aggregation. Vernonia condensata (Asteraceae) is known to attract species of leafhoppers, most of them important vectors of the citrus variegated chlorosis (CVC). In this study, we evaluated the role of volatiles of V. condensata on the orientation of Bucephalogonia xanthophis (Hemiptera: Cicadellidae). Four-arm olfactometer bioassays showed that only males were attracted to the volatiles of the host-plants Citrus sp. and V. condensata. Furthermore, fresh leaves of V. condensata induced a stronger response than volatiles from hexane-extracted leaves. This study opens the possibility to utilize V. condensata volatiles for pest management programs of B. xanthopis.Os voláteis de plantas são sinais importantes para a orientação de insetos herbívoros. É possível que esses compostos indiquem que a planta é apropriada para alimentação e desenvolvimento larval, ou para agrupamento reprodutivo. Vernonia condensata (Asteraceae) atrai espécies de cigarrinhas, muitas delas vetores da clorose variegada dos citros (CVC). Neste trabalho, foi avaliado o papel dos voláteis de V. condensata na orientação de Bucephalogonia xanthophis (Hemiptera: Cicadellidae). Bioensaios em olfatômetro de quatro braços mostraram que somente os machos foram atraídos pelos voláteis das plantas hospedeiras Citrus sp. e V. condensata, sendo que os voláteis das folhas frescas de V. condensata induziram uma maior resposta quando comparada aos extratos hexânicos da planta. A possibilidade de usar os voláteis de V. condensata abre novas perspectivas para programas e alternativas para o manejo de pragas.Fundação de Amparo à Pesquisa no Estado de São Paulo (FAPESP

Efeitos tardios da co exposição larval a doses realísticas do inseticida clotianidina e do fungicida piraclostrobina : avaliação da longevidade das operárias adultas de apis mellifera africanizada

Nos últimos anos, as abelhas vêm sofrendo um declínio populacional que afeta os serviços ecossistêmicos de polinização, dentre os fatores desse declínio estão os agrotóxicos. Com o objetivo de avaliar o efeito da exposição a uma mistura do inseticida clotianidina e do fungicida piraclostrobina no desenvolvimento de Apis mellifera africanizada, larvas de primeiro instar obtidas de três colônias foram transferidas para cúpulas com dieta artificial padronizada. Realizou-se exposição repetida por via oral nas larvas, do terceiro ao sexto dia do bioensaio. O consumo total do inseticida foi de 0,2364 ng/larva e do fungicida de 23,63 ng/larva. Avaliou-se a longevidade das abelhas emergidas e realizou a caracterização química dos compostos por infravermelho. Os agrotóxicos não apresentaram efeitos deletérios nas larvas e pupas. Entretanto, as abelhas expostas ao inseticida isolado e aos dois agrotóxicos combinados apresentaram redução na longevidade dos adultos emergidos (p<0,01). O decréscimo no tempo de sobrevivência foi maior no grupo exposto apenas ao inseticida, sendo que a presença do fungicida no grupo co-exposto atenuou este decréscimo na longevidade, possivelmente por uma interação dos compostos químicos dos agrotóxicos, evidenciada pela mudança no padrão do espectrograma. O fungicida isolado não alterou a longevidade das abelhas (p>0,1). A co-exposição pode ter diminuído a toxicidade do inseticida por meio de interações químicas e/ou facilitado o processo de desintoxicação destes xenobióticos no organismo, reduzindo a mortalidade. Do ponto de vista da dinâmica populacional da colônia, estes dados são preocupantes, visto que as concentrações dos agrotóxicos foram encontradas nos recursos alimentares das abelhasFil: Menezes Tadei, Rafaela. Universidade Federal de Sao Carlos (Brasil)Fil: Aparecido, J.. Universidade Federal de Sao Carlos (Brasil)Fil: Silva Zacarin, Elaine C. M.. Universidade Federal de Sao Carlos (Brasil

Losses of Brazilian bees: an overview of factors that may affect these pollinators

The Neotropical region to which Brazil belongs, has a great and rich diversity of natives bees, up to a total of 3.000 species including the allochtone genus Apis that by natural crossing among European and African races produced a hybrid called Africanized honeybee. In this way, beekeeping enjoys a spectacular moment with good production mainly of honey and propolis from Apis mellifera, causing Brazil to be recognized around the world as a country with great potential. Brazilian bee losses nevertheless remain a question, compared with countries of the northern hemisphere where several reports show that the vanishing of honeybees is associated with diseases caused by Varroa, Nosema, virus or pesticides. We can suggest different issues in the Brazilian situation that are directly influencing the honeybee population. Given the extension of the territory and rich flora, all possible food resources and nest sites for the good development of bees may be considered present. However, we verified that annual bee losses in the Southeast can reach 20-30%, mainly due the genetic mechanisms of swarming (nest abandon). Many times the major factor leading to nest abandon is lack of food, often taken mistakenly by the untrained beekeeper as death of the hive caused by diseases or pesticides. Although in Brazil diseases do not represent an important problem for Africanized honeybees, some cases of presence of Nosema ceranae and Varroa destructor led the specialists to precaution and monitoring the colonies. In spite of this, the Brazilian beekeeping is managed without use of any acaricide or antibiotic, producing contaminant-free products. As to pesticides, Brazil has a particular climatic and soil condition that might differently affect the risk of exposure of bees to xenobiotics. For example, comparing the dynamics of carbamate pesticides in soil between Brazil and Europe, it was found that in our condition ten-fold more time is needed to obtain the metabolites sulfone and sulfoxide, both more soluble and toxic than it precursor. Comparing the pesticides consumption, currently Brazil has become the world leader followed by USA, with a total spending of 44.9% herbicide, 28.5% insecticide and 22.1% fungicide. Even with this consumption Brazil still belongs to the group that uses a relatively small amount of active ingredient per hectare, less than Japan and France. However cultures like tomato, potato, citrus, cotton and coffee that are often visited by bees during bloom, are also those where the use of pesticides is needed for the pest control. Thus, little is known yet about pesticide losses of the Brazilian bees! What are real effects of pesticides, toxic plants, diseases, genetic improvement, beekeeping management, starvation or interactions among these? Therefore, our local group on ecotoxicological assessment is trying to increase the knowledge on the pesticides hazard to bees (Apis and non-Apis) in order to protect these. Keywords: Brazilian bees, overview, pesticide, diseases, environment, protection

Fipronil effect on the frequency of anomalous brood in honeybee reared in vitro

Larvae of honeybee workers were exposed to the insecticide fipronil during the feeding phase. To evaluate the effect of fipronil in the post-embryonic development of africanized Apis mellifera, bioassays of toxicity were done. The bioassays were performed by acute exposure applying 1μL of distilled water for control (I) and for experiments: 0.5 ng a.i./μL of fipronil; 5 ng a.i./μL of fipronil and 20 ng a.i./ μL of fipronil. Triplicates were performed for all treatments. The results showed that the rate of anomalous pupae in exposed honeybees was statistically significant in relationship to the control (p <0:03). The most frequent abnormalities were: high pigmentation on the proximal and distal larval body and body malformation, such as absence of head and limbs. Pink eye pupa and white eyed pupae presented malformations in their larval bodies, but with the eye developed. It is assumed that the fat body is related to the high rate of anomalies, since this tissue has proteins linked to the process of metamorphosis. Furthermore, the fat body may be participating in the regulation of juvenile hormone during the process of metamorphosis, and consequently in the release of ecdysteroid hormones that are involved in the change from larva to adult. The high rate of abnormalities in the pupal stage of individuals exposed to fipronil raises concerns about the impacts caused in the colonies of bees and population decline of pollinators. Keywords: bees, larvae, pupae, metamorphosis, anomalies, fiproni

EVALUATION OF THE MUZAMBA NA CAÇAMBA GAME IN TEACHING SOLID WASTE DISPOSAL RULES

A programação de contingências de ensino para promover a aprendizagem de comportamentos pró-ambientais pode ser realizada por meio de diversos instrumentos, incluindo os jogos educativos. Este estudo avaliou: (a) a eficácia do jogo Muzamba na Caçamba no ensino de regras de descarte de resíduos sólidos, (b) o engajamento promovido pelo jogo e sua usabilidade. Dezoito escolares participaram de três etapas do procedimento: (a) avaliação pré-intervenção com o Teste de Ligar, o jogo avaliativo Tapa Certo e uma entrevista semi-estruturada realizada com os responsáveis dos participantes; (b) uma sessão de intervenção com o jogo Muzamba na Caçamba; (c) avaliação pós-intervenção com os mesmos instrumentos da avaliação pré-intervenção. A comparação dos resultados do Teste de Ligar e do jogo avaliativo Tapa Certo entre pré e pós-intervenção demonstrou que 7 e 15 dos 18 participantes apresentaram, respectivamente, aumento no número de respostas corretas. Com relação ao engajamento, verificou-se que 10 dos 18 participantes emitiram comportamentos de aprovação do jogo, dois demonstraram desaprovação e nenhum participante solicitou a interrupção das jogadas. Quanto à usabilidade do jogo verificou-se que apenas 4 dos 18 participantes solicitaram ajuda e três fizeram mais do que duas perguntas sobre as regras do jogo. O baixo desempenho dos participantes no Teste de Ligar foi provavelmente devido às condições de aplicação do teste. Conclui-se que o jogo Muzamba na Caçamba demonstrou ser um instrumento que promove a aprendizagem de regras de descarte de resíduos sólidos, que apresenta usabilidade e promove o engajamento dos participantes.Palavras-chave: Resíduos sólidos; reciclagem análise do comportamento; jogo educativo; adolescentes.Programming teaching contingencies to promote learning of pro-environmental behaviors can be carried out through several instruments, including educational games. This study evaluated: (a) the effectiveness of the Muzamba na Caçamba game in teaching solid waste disposal rules, (b) the engagement promoted by the game, and its usability. Eighteen students participated in three stages: (a) pre-intervention evaluation with the Matching Pairs Test, the evaluative Tapa Certo game and a semi-structured interview conducted with the participants’ parents and legal guardians (b) an intervention session with the Muzamba na Caçamba game; (c) post-intervention assessment with the same instruments as the pre-intervention assessment. The comparison of the results of the Matching Pairs Test and the evaluative Tapa Certo game between pre- and post-intervention showed that 7 and 15 of the 18 participants showed, respectively, an increase in the number of correct responses. Concerning the engagement, we found that 10 of the 18 participants emitted behaviors that approved the game, two showed disapproval, and none of the participants asked to stop playing. Regarding the usability of the game, only 4 of the 18 participants asked for help, and three asked more than two questions about the rules of the game. The poor performance of the participants in the Matching Pairs Test was probably related to the test administration conditions. We concluded that the Muzamba na Caçamba game proved to be an instrument that promotes the learning of solid waste disposal rules, which presents usability and further participant engagement.Keywords: Solid waste; recycling; behavior analysis; educational game; adolescents

Novel findings on the impact of chytridiomycosis on the cardiac function of anurans: sensitive vs. tolerant species

Background Understanding of the physiological effects of chytridiomycosis is crucial to worldwide amphibian conservation. Therefore, we analyzed the cardiac function of two anuran species (Xenopus laevis and Physalaemus albonotatus) with different susceptibilities to infection by the causative agent of chytridiomycosis, Batrachochytrium dendrobatidis (hereafter Bd). Methods We analyzed the in situ heart rate (fH - bpm), relative ventricular mass (RVM -%), and Ca2+ handling in heart of Bd infected animals compared to uninfected controls of both study species. Results Bd infection resulted in a 78% decrease in contraction force values in P. albonotatus when compared to the less susceptible X. laevis. This negative effect was even more evident (82%) for the cardiac pumping capacity. The time to reach peak tension was 125% longer in P. albonotatus than in X. laevis, and cardiac relaxation was 57% longer. Discussion These results indicate a delay in the cardiac cycle of P. albonotatus on a beat-to-beat basis, which was corroborated by the bradycardia observed in situ. In summary, Bd-sensitive species present impaired cardiac function, which could be a factor in mortality risk. The more pronounced effects of Bd in P. albonotatus may not only result from electrolyte imbalance, as previously reported, but also could be an effect of toxins produced by Bd. For X. laevis, the ability to promote cardiac adjustments seems to be an important homeostatic feature that allows greater tolerance to chytridiomycosis. This study provides new physiological mechanisms underlying the tolerance or susceptibility of amphibian species to chytridiomycosis, which determine their adaptability to survive in the affected environments

Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012