The effect of sub-lethal doses of Azadirachta indica (Meliaceae) oil on the midgut of Spodoptera frugiperda (Lepidoptera, Noctuidae)

Revista Brasileira de Entomologia

Antonia Railda Roel²  Doroty M. Dourado²  Rosemary Matias²  Karla R. A. Porto²  Aline V. Bednaski²  Reginaldo B. Da Costa¹ 

[1] ,Centro de Pesquisas do PantanalCuiabá MT ,Brazil

关键词: Fall armyworm;    histological analysis;    insecticidal plants;    neem;    Análise histológica;    lagarta-do-cartucho;    nim;    plantas inseticidas;   

DOI  :  10.1590/S0085-56262010000300024

来源: SciELO

【 摘 要 】

The fall armyworm, Spodoptera frugiperda, is one of the major field pests for maize production. It is mainly controlled by means of synthetic, and more recently by resistant cultivar of maize expressing Bt toxins. The neem tree, Azadirachta indica, is a plant that can potentially control insects with the advantage of being food and environmental safe. The aim of this study was to assess the effect of neem oil on the development and survival of S. frugiperda caterpillars by assessing histological alterations caused on their midgut. Newly hatched caterpillars were submitted to three neem oil concentrations: 0.006; 0.05; 0.4%, which were added to their artificial diet. Ten 3rd instar caterpillars, taken from each treatment, were submitted to histological analysis. The alimentary canals from the specimens were fixed in Baker for 12 hours, desiccated and diaphanized in alcohol/xylol (1:1) and xylol. After placing the samples in paraffin, they were sliced in 8 µm sections and stained with hematoxylin-eosin stain. The neem oil added to the diet of S. frugiperda caused total mortality at dose of 0.4% whilst still in the first instars, prolonged the larval and pupal stages, and reduced the pupal weight. Histo-physiological alterations such as degeneration of the epithelial lining of the midgut and in the peritrophic matrix were found at all concentrations of neem oil.

【 授权许可】

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