Toxicidade e genotoxicidade do biopesticida Azamax™ em ovário e intestino de Ceraeochrysa claveri (Neuroptera:Chrysopidae)
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Data
2019-08-05
Autores
Pastrana, Bertha Irina Gastelbondo
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Universidade Estadual Paulista (Unesp)
Resumo
O biopesticida Azamax™ tem sido utilizado como uma alternativa aos inseticidas sintéticos para o controle de pragas em plantações. Além disso, este produto tem obtido destaque por poder se associar ao uso de predadores naturais no controle biológico previsto pelo Manejo Integrado de Pragas (MIP). Dentre os modelos biológicos, destaca-se a espécie Ceraeochrysa claveri, sobretudo devido sua característica predadora na fase de larva com ampla variedade de presas e alto potencial reprodutivo na fase adulta. Embora a azadiractina, ingrediente ativo do Azamax™, já tenha sido relacionada com a indução de efeitos citotóxicos em insetos, ainda não há dados na literatura sobre os possíveis efeitos da sua ingestão indireta em células germinativas e intestinais de C. claveri. Desta forma, o objetivo deste estudo foi avaliar o efeito tóxico e genotóxico do Azamax™ em células do ovário e do intestino de fêmeas de C. claveri. As larvas foram alimentadas ad libitum, com ovos de Diatraea saccharalis tratados com duas diferentes concentrações do Azamax™ (0,3% e 0,5%) durante todo o seu período larval (n=150 larvas/grupo). As análises morfológicas, ultraestruturais e de genotoxicidade foram realizadas após os indivíduos se desenvolverem até a fase adulta. Os resultados indicaram que a exposição ao Azamax™ somente na fase larval, induziu sinais de toxicidade em todas as fases do desenvolvimento do inseto, como: (a) significante taxa de mortalidade a partir do 3º instar larval; (b) prepupa e pupas inviáveis; (c) alterações na duração das fases (larva, prepupa e pupa); (d) marcantes malformações nos adultos emergidos; (e) danos primários no DNA de células intestinais e células dos ovários; (f) alterações ultraestruturais significantes nas células ovarianas (desorganização dos cistos/folículos ovarianos, dilatação do envelope nuclear e do retículo endoplasmático das células ovarianas e grande número de células com morfologia sugestiva de morte celular apoptótica. Nas condições experimentais utilizadas, os presentes dados indicam que o Azamax™ afeta o desenvolvimento e o potencial reprodutivo de Ceraeochrysa claveri, o que pode afetar a manutenção da espécie no ecossistema e, consequentemente, a continuidade do controle biológico natural exercido por esta espécie predadora de pragas.
Azamax ™ biopesticide has been used as an alternative to synthetic insecticides for pest control in several crops. Besides, this product has been highlighted because this association use with natural predators for biological control in the integrated pest management programs (IPM). Among the biological models, is commonly use the specie Ceraeochrysa claveri, above all its predatory characteristic at the larval stage with a wide variety of prey and high reproductive potential in the adult stage. Azadirachtin, active ingredient of Azamax ™, has been related to the induction of cytotoxic effects in insects, although it has not been published in literature about the possible effects of Azamax and its indirect ingestion in germ and intestinal cells of C. claveri. From this, the aim of this study, is to evaluate the toxic and genotoxic effect of Azamax ™ in cells of the ovary and intestine of females of C. claveri. Larvae were fed ad libitum with treated eggs of Diatraea saccharalis at different concentrations of Azamax ™ (0.3% and 0.5%) during all or their larval period (n = 150 larvae/group). Morphological, ultrastructural and genotoxic analyzes carried out when individuals reached adult stage. The results indicated that exposure to Azamax ™ only in the larval phase induced signs of toxicity at all stages of insect development, such as: (a) significant mortality rate from 3rd instar larval; (b) prepupa and pupae inviable; (c) changes in the duration of the phases (larva, prepupa and pupa); (d) marked malformations in the emergent adults; (e) primary damage to the DNA of intestinal cells and ovarian cells; (f) significant ultrastructural alterations in ovarian cells (disorganization of ovarian cysts/follicles, dilatation of nuclear envelope and endoplasmic reticulum of ovarian cells, and large numbers of cells with morphology suggestive of apoptotic cell death. Under experimental conditions used in this study, Azamax ™ affects development and the reproductive potential of Ceraeochrysa claveri, and it can affect the maintenance of species in the ecosystem, and consequently, the natural biological control exercised by this predator species of pests.
Azamax ™ biopesticide has been used as an alternative to synthetic insecticides for pest control in several crops. Besides, this product has been highlighted because this association use with natural predators for biological control in the integrated pest management programs (IPM). Among the biological models, is commonly use the specie Ceraeochrysa claveri, above all its predatory characteristic at the larval stage with a wide variety of prey and high reproductive potential in the adult stage. Azadirachtin, active ingredient of Azamax ™, has been related to the induction of cytotoxic effects in insects, although it has not been published in literature about the possible effects of Azamax and its indirect ingestion in germ and intestinal cells of C. claveri. From this, the aim of this study, is to evaluate the toxic and genotoxic effect of Azamax ™ in cells of the ovary and intestine of females of C. claveri. Larvae were fed ad libitum with treated eggs of Diatraea saccharalis at different concentrations of Azamax ™ (0.3% and 0.5%) during all or their larval period (n = 150 larvae/group). Morphological, ultrastructural and genotoxic analyzes carried out when individuals reached adult stage. The results indicated that exposure to Azamax ™ only in the larval phase induced signs of toxicity at all stages of insect development, such as: (a) significant mortality rate from 3rd instar larval; (b) prepupa and pupae inviable; (c) changes in the duration of the phases (larva, prepupa and pupa); (d) marked malformations in the emergent adults; (e) primary damage to the DNA of intestinal cells and ovarian cells; (f) significant ultrastructural alterations in ovarian cells (disorganization of ovarian cysts/follicles, dilatation of nuclear envelope and endoplasmic reticulum of ovarian cells, and large numbers of cells with morphology suggestive of apoptotic cell death. Under experimental conditions used in this study, Azamax ™ affects development and the reproductive potential of Ceraeochrysa claveri, and it can affect the maintenance of species in the ecosystem, and consequently, the natural biological control exercised by this predator species of pests.
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Palavras-chave
Pesticida natural, Reprodução, Insetos não alvo, Crisopídeo, Danos no DNA, Natural pesticide, Reproduction, non-target insects, Green lacewings, DNA damage