Brain morphophysiology of Africanized bee Apis mellifera exposed to sublethal doses of imidacloprid

Several synthetic substances are used in agricultural areas to combat insect pests; however, the indiscriminate use of these products may affect nontarget insects, such as bees. In Brazil, one of the most widely used insecticides is imidacloprid, which targets the nervous system of insects. Therefore, the aim of this study was to evaluate the effects of chronic exposure to sublethal doses of imidacloprid on the brain of the Africanized Apis mellifera. The organs of both control bees and bees exposed to insecticide were subjected to morphological, histochemical and immunocytochemical analysis after exposure to imidacloprid, respectively, for 1, 3, 5, 7, and 10 days. In mushroom bodies of bees exposed to imidacloprid concentrations of LD50/10 and in optic lobes of bees exposed to imidacloprid concentrations of LD 50/10, LD50/100, and LD50/50, we observed the presence of condensed cells. The Feulgen reaction revealed the presence of some cells with pyknotic nuclei, whereas Xylidine Ponceau stain revealed strongly stained cells. These characteristics can indicate the occurrence of cell death. Furthermore, cells in mushroom bodies of bees exposed to imidacloprid concentrations of LD50/10 appeared to be swollen. Cell death was confirmed by immunocytochemical technique. Therefore, it was concluded that sublethal doses of imidacloprid have cytotoxic effects on exposed bee brains and that optic lobes are more sensitive to the insecticide than other regions of the brain. © 2013 Springer Science+Business Media New York.

The Phylogeographic History of the New World Screwworm Fly, Inferred by Approximate Bayesian Computation Analysis

Insect pest phylogeography might be shaped both by biogeographic events and by human influence. Here, we conducted an approximate Bayesian computation (ABC) analysis to investigate the phylogeography of the New World screwworm fly, Cochliomyia hominivorax, with the aim of understanding its population history and its order and time of divergence. Our ABC analysis supports that populations spread from North to South in the Americas, in at least two different moments. The first split occurred between the North/Central American and South American populations in the end of the Last Glacial Maximum (15,300-19,000 YBP). The second split occurred between the North and South Amazonian populations in the transition between the Pleistocene and the Holocene eras (9,100-11,000 YBP). The species also experienced population expansion. Phylogenetic analysis likewise suggests this north to south colonization and Maxent models suggest an increase in the number of suitable areas in South America from the past to present. We found that the phylogeographic patterns observed in C. hominivorax cannot be explained only by climatic oscillations and can be connected to host population histories. Interestingly we found these patterns are very coincident with general patterns of ancient human movements in the Americas, suggesting that humans might have played a crucial role in shaping the distribution and population structure of this insect pest. This work presents the first hypothesis test regarding the processes that shaped the current phylogeographic structure of C. hominivorax and represents an alternate perspective on investigating the problem of insect pests. © 2013 Fresia et al.

Detecção da citotoxicidade, genotoxicidade e mutagenicidade do inseticida fipronil no organismo teste Allium cepa

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ocorrência e dinâmica populacional de insetos-pragas e predadores associados às culturas de nabo forrageiro e milho em sistemas de plantio direto, em Chapadão do Sul, MS

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Dinâmica populacional de mosca-negra-dos-citros (Aleurocanthus woglumi Ashby, 1915) em pomares de citros em sistema agroflorestal e monocultura

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Identificação e caracterização de genes cry3, vip1, vip2 E vip1/vip2 em isolados de Bacillus thuringiensis E toxicidade em larvas de Anthonomus grandis (Boheman, 1883) (Coleoptera: curculionidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Obtenção de mutantes de Bacillus thuringiensis por inserção do transposon Tn-5 e avaliação da toxicidade frente a larvas de Spodoptera frugiperda

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Potencial de nematóides entomopatogênicos para o controle da mosca-do-mediterrâneo Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) e do gorgulho-da¬goiaba Conotrachelus psidii (Marshal) (Coleoptera: Curculionidae)

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Influência de sistemas de semeadura na população de pragas e nas características morfofisiológicas em cultivares de soja

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Resistência de genótipos de feijoeiro a Chrysodeixis includens (Walker) (Lepidoptera: Noctuidae)

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Efeito do óleo de nim (Azadirachta indica A. Juss) no intestino médio de Ceraeochrysa claveri (Navás, 1911) (Neuroptera: Chrysopidae): estudo citoquímico, imunocitoquímico e ultraestrutural

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Aspectos bioecológicos de Pseudoplusia includens (Walker, 1857) (Lepidoptera: Noctuidae) em cultivares convencionais e transgênicas de algodoeiro

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Resistência de germoplasma silvestre de amendoim (arachis spp.) a Enneothrips flavens Moulton, 1941 (Thysanoptera: Thripidae) e Stegasta bosquella (Chambers, 1875) (Lepidoptera: Gelechiidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de diferentes populações de Cydia pomonella (Lepidoptera: Tortricidae) em temperaturas variáveis e consequências na modelagem fenológica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Efeito da temperatura e de hospedeiros no desenvolvimento de Diaeretiella rapae (McIntosh) (Hymenoptera: Braconidae, Aphidiinae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)