Correia Alicely A, Wanderley-Teixeira Valéria, Teixeira Alvaro A C, Oliveira José V de, Torres Jorge B
Programa de Pós-Graduação em Entomologia Agrícola.
Neotrop Entomol. 2009 Jan-Feb;38(1):829-837. doi: 10.1590/s1519-566x2009000100008.
Research involving plants with insecticide activity evolved significantly in the last decades. Among these plants, the neem tree, Azadirachta indica, is commonly used against several insects, mainly Lepidoptera. The neem efficiency depends on the target insect and on the concentration used. A barrier against potential toxic agents ingested together with the food is the alimentary canal. Thus, this research aimed to describe the histology of the alimentary canal of Spodoptera frugiperda (J E Smith) larvae fed on leaves treated with neem (Neemseto) at a concentration of 0.5% and 1.0% and non treated, at different intervals (48, 96, 144, 192 and 240 h), by quantifying the regenerative cells and analyzing the secretion of the mesenteron histochemically. Larvae were immobilized at low temperatures (-4 degrees C), the alimentary canal was removed, fixed in Boüin s aqueous, embedded in paraplast and historesin, sectioned and stained with hematoxilin-eosin and periodic acid- Schiff. The histology of the alimentary canal of S. frugiperda was similar to other lepidopterans. Neem effects on morphology were seen only in the mesenteron, depending on the time and concentration used, such as: epithelium, reduction on regenerative cells and on the secretory activity in this region, confirmed by the histochemistry in both neem concentrations. These alterations were observed after 96 h at 1.0%, and 144 h at 0.5%. These results indicate that neem (Neemseto), at the concentrations studied, may be effective to control S. frugiperda because it promotes meaningful morphological alterations in the mesenteron.
在过去几十年中，涉及具有杀虫活性植物的研究有了显著进展。在这些植物中，印楝树（Azadirachta indica）通常用于防治多种昆虫，主要是鳞翅目昆虫。印楝的效果取决于目标昆虫和所使用的浓度。消化道是抵御与食物一同摄入的潜在有毒物质的一道屏障。因此，本研究旨在描述取食经0.5%和1.0%浓度印楝（Neemseto）处理以及未处理叶片的草地贪夜蛾（Spodoptera frugiperda (J E Smith)）幼虫在不同时间间隔（48、96、144、192和240小时）的消化道组织学，通过量化再生细胞并对中肠进行组织化学分析其分泌情况。将幼虫在低温（-4℃）下固定，取出消化道，固定于波因氏水溶液中，包埋于石蜡和组织树脂中，切片并用苏木精-伊红和过碘酸-希夫染色。草地贪夜蛾消化道的组织学与其他鳞翅目昆虫相似。印楝对形态的影响仅在中肠中可见，这取决于所使用的时间和浓度，例如：上皮细胞、该区域再生细胞数量减少以及分泌活性降低，这在两种印楝浓度下的组织化学分析中均得到证实。在1.0%浓度下96小时后以及0.5%浓度下144小时后观察到了这些变化。这些结果表明，在所研究的浓度下，印楝（Neemseto）可能对防治草地贪夜蛾有效,因为它会在中肠中引发有意义的形态学改变。
