薇甘菊提取物对螺旋粉虱的生物活性

【背景】薇甘菊和螺旋粉虱均为我国入侵物种，且二者之间无寄生关系。本研究旨在挖掘薇甘菊的利用价值，为其在螺旋粉虱生态防控中的使用提供依据。【方法】采用药膜法和田间喷雾法，研究了4种提取方法（冷浸法、索氏提取法、冷浸—索氏提取法、温浸法）获得的薇甘菊提取物对螺旋粉虱成虫的室内生物活性和田间防治效果。【结果】在所选择的4种提取方法中，索氏提取法和温浸法的提取率最高，分别为9.90%和9.35%；冷浸—索氏提取法和冷浸法的提取率相对较低，分别为7.73%和4.50%。室内生物测定表明，采用冷浸法、冷浸—索氏提取法、索氏提取法和温浸法所获得的薇甘菊提取物对螺旋粉虱成虫的LC50值分别为8.94、9.03、6.32和7.51 mg·mL-1，但由于95%置信区间存在重合，不同提取物活性之间的差异不显著。田间试验结果则表明，不同提取方法获得的薇甘菊提取物对螺旋粉虱成虫都具有良好的防治效果，100倍液处理7 d后，对螺旋粉虱的校正防效均在75%以上。但是，索氏提取法和温浸法提取物防治效果显著优于冷浸—索氏提取法和冷浸法。【结论与意义】薇甘菊提取物对螺旋粉虱具有生物活性。

Bio-activities of Mikania micrantha extracts on Aleurodicus disperses

【Background】Mikania micrantha （Asteraceae） and Aleurodicus disperses （Aleyrodidae） are two invasive species of China with non-parasitism. The study sought evidence for ecological control of A.disperses by M.micrantha by its plant-based alkaloids. 【Method】The laboratory bio-activities and field effects of M.micrantha extracts were examined using four extraction methods （cool maceration, Soxhlet extraction, cool maceration followed by Soxhlet extraction, warm maceration）. M.micrantha extracts were tested on A.disperses using test tube residual film and field spray method. 【Result】Among the four different extraction methods, Soxhlet extraction and warm maceration showed higher extraction rate （9.90% and 9.35%, respectively） followed by cool maceration with Soxhlet and cool maceration extraction methods （extraction ratio of 7.73% and 4.50%, respectively）. The laboratory bioassay results indicated no significant difference among the bio-activities of M.micrantha extracts prepared using different extract methods on A.disperses under laboratory conditions. However, significant differences were found under field conditions： Soxhlet extraction and warm maceration extracts had higher effect than those of cool maceration with Soxhlet and cool maceration. All extracts showed good effects on A.disperses, and the best method （Soxhlet extraction）, at 100× times dilution, killed over 75% of A.disperses individuals after 7 days. 【Conclusion and significance】Extracts of M.micranthashowed inhibition against another invader, A.disperses, so its success may involve plant-based alkaloids.