The commercial insecticide Fastac Duo is a combined insecticide, widely used in different crops, acting on insects, affecting both pests and pollinators, such as bees. In this study, the effects of sublethal concentrations of Fastac Duo in stingless bees Scaptotrigona bipunctata were evaluated. Worker forager bees were exposed to the insecticide and histochemical and morphological analyses were conducted after 24, 48 and 72 h of ingestion. Brain analysis of S. bipunctata revealed changes in the chromatin condensing state according to exposure time and insecticide concentration when compared to the control group. Morphological changes were observed in the midgut in all concentrations and exposure times, which may interfere in several physiological processes. In conclusion, although the concentrations used in the study did not cause high mortality, it induced changes in the internal morphology that can lead to changes in bee activity.

RESUMO -Crescente interesse tem se estabelecido para a análise da diversidade genética de espécies Conyza bonariensis, C. canadensis e C. sumatrensis, popularmente conhecidas como buva ou voadeira, que nos últimos anos vêm causando vários prejuízos nas lavouras do Brasil e do mundo, principalmente nas plantações de soja. A proposta do presente estudo foi estimar a variabilidade genética de amostras de C. sumatrensis provenientes da região noroeste do Estado do Paraná. A análise de isozimas em tecidos de folhas das plantas de C. sumatrensis foi realizada para estimar a variabilidade genética dentro de cada população e entre populações diferentes, no sentido de recomendar um tratamento diferencial ou uniforme para o controle dessas plantas daninhas na referida região. Foram analisados quatro sistemas enzimáticos (ACP, GPI, MDH e PGM) e detectados 10 locos com 10 alelos, os quais não apresentaram diversidade genética dentro e entre as populações analisadas, comprovado pela presença de apenas indivíduos homozigotos. As enzimas analisadas no presente estudo indicaram que as plantas das três regiões são geneticamente uniformes, e a uniformidade genética verificada para os referidos locos é um indicativo prévio de que é possível utilizar doses equivalentes do glifosato para controlar o crescimento desses biótipos. Palavras-chave: isoenzimas, polimorfismo, Conyza, buva, variabilidade genética. ABSTRACT -There has been a growing interest for the analysis of genetic diversity of species

This work carried out to evaluates the polymorhism in the silkworm of different lineages using the isoenzymes electrophoresis to detect biochemical markers and to investigate the genetics of populations for those lineages. They were used as samples individual extracts of silk glands of second day old larvas of the fifth instar, originating from seven Japanese lineages and eight pure Chinese lineages maintained by the Cocamar-Cooperativa Agroindustrial de Maringá. The isozymes acid phosphatase (ACP), alkaline phosphatase (AKP) and carbonic anhydrase (CA) they were submitted to the electrophoresis in starch gels 14%. The esterases (EST) were analyzed in polyacrylamide gels to 10% and stained with α and β-naphtyl acetate. The total of 21 loci was detected, and 04 (19.05%) they are polymorphic, Est-11, Acp, Akp, Ca. The fixation index (F is ) for the analyzed isozymes it was 0.0751, indicating excess of homozygotes. The value of F st (0.6128) it shows that the lineages are well differentiated. The dendrogram obtained with the values of genetic distance didn't separate the Chinese and Japanese lineages analyzed totally. That preliminary evaluation of the lineages of B. mori shows that they present genetic material that it can be used in breeding programs that have the purpose of producing hybrid for silk production.Análise genética de polimorfismos bioquímicos em linhagens do bicho da seda (Bombyx mori L.) RESUMO. Este trabalho teve como objetivo avaliar o polimorfismo em lagartas do bicho-da-seda de diferentes linhagens utilizando a eletroforese de isoenzimas para detectar marcadores bioquímicos e investigar a genética de populações para essas linhagens. Foram utilizados como amostras extratos individuais de glândulas sericígenas de lagartas do segundo dia da quinta idade, de sete linhagens japonesas e oito linhagens chinesas puras mantidas pela Cocamar-Cooperativa Agroindustrial de Maringá. As isozimas fosfatase ácida (ACP), fosfatase alcalina (AKP) e anidrase carbônica (CA) foram avaliadas por meio de eletroforese em géis de amido de milho a 14%. As esterases (EST) foram analisadas por meio de eletroforese vertical em géis de poliacrilamida a 10% e coloração com α e β-naftil acetato. Foram observados 21 locos, dentre os quais quatro (19.05%) são polimórficos, Est-11, Acp, Akp, Ca. O índice de fixação (F is ) para as isozimas analisadas foi 0.0751, indicando excesso de homozigotos. O valor de F st (0.6128) permite sugerir que as linhagens estão bem diferenciadas. O dendograma obtido a partir dos valores de distância genética não separou totalmente as linhagens chinesas e japonesas analisadas. Essa avaliação preliminar das linhagens de B. mori mostra que elas apresentam material genético que pode ser utilizado em programas de cruzamentos que tenham a finalidade de produzir híbridos para produção de seda.Palavras-chave: bicho-da-seda, polimorfismos genéticos, isoenzimas.

Beginning in 2006, beekeepers on the east coast of the United States began to report severe declines in their honeybee colonies. Because of the severity and unusual circumstances of these declines, scientists have called this phenomenon colony collapse disorder (CCD). In 2019, 500 million dead bees were found in Brazil. Analyzes of dead bees identified agrochemicals in approximately 80% of them. Thus, it is believed that one of the main causes for CCD is the intensive use of agrochemicals. Neonicotinoids are the most widely used class of insecticides in the world, they are used for pest control in a variety of crops. However, they can not only affect insects considered pests, but also non-target organisms, such as pollinators. This class of insecticides is divided into five main active ingredients: imidacloprid, thiamethoxam, clothianidin, thiacloprid and acetamiprid. Several studies demonstrate that sublethal concentrations of these insecticides affect bees in different ways, such as navigation memory and muscle movements. Thus, this review aims to report the studies published between 2014 and 2019 regarding the contamination of bees with sublethal doses of the five active ingredients of the neonicotinoid class. Imidacloprid and thiamethoxam are the most used insecticides of this class and show high toxicity to bees. On the other hand, clothianidin showed the least sublethal effects on bees on the studies reported on this review. Thiacloprid and acetamiprid, although less used in agriculture, also impair several aspects of bee health. Thus, it is possible to infer that neonicotinoids are contributing to the disappearance of bees worldwide.

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