The toxicity and physiological effect of goniothalamin, a styryl-pyrone, on the generalist herbivore, Spodoptera exigua

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• 作者：Sengottayan Senthil-Nathan ; Man-Young Choi ; Chae-Hoon Paik ; K ; aswamy Kalaivani
• 关键词：Goniothalamin ; Styryl-pyrone ; Beet armyworm ; Moulting ; Nutrition ; Gut histology
• 刊名：Chemosphere
• 出版年：2008
• 出版时间：July 2008
• 年：2008
• 卷：72
• 期：9
• 页码：1393-1400
• 全文大小：710 K

文摘

Efficacy of Goniothalamin a styryl-pyrone isolated from Goniothalamus wightii Hook.f. and Thoms, against beet armyworm, Spodoptera exigua (Hübner), populations was determined under laboratory condition. The experiments were carried out with concentrations of 5, 10, 15 and 30 ppm in an artificial diet and compared with control insects. Laboratory bioassay showed that the goniothalamin had a strong effect on food utilization, moulting and gut histology. The food consumption and conversion of ingested and digested food to body matter decreased with increasing pyrone concentration. The antifeedant activity was also observed in larvae of S. exigua. The treated third instar larvae exhibited mortality in a dose dependent manner. At 5, 10, 15 and 30 ppm/insect, the pyrone gave 23 % , 45 % 63 % and 100 % mortality respectively. The larvae of S. exigua gained significantly less weight until pupation in the 10 and 15 ppm pyrone concentrations. Duration of larval period was also affected after treatment with pyrone. The metamorphosis was delayed with additional moulting (7th instar) after treatment with 10 and 15 ppm of goniothalamin, the percentage of larvae successfully moulted into progressive instars was significantly decreased with an increase in pyrone concentrations. The effects of goniothalamin on midgut ultrastructure of third instar larvae of S. exigua were investigated by using light microscopy. Cross sections of the midgut showed that the epithelial cells were destroyed. Significant damage of the midgut epithelium was observed along with lysis.