Choi Man-Yeon, Tang Siew Bee, Ahn Seung-Joon, Amarasekare Kaushalya G, Shearer Peter, Lee Jana C
USDA ARS Horticultural Crops Research Unit, 3420 NW Orchard Avenue, Corvallis, OR 97330, USA.
USDA ARS Horticultural Crops Research Unit, 3420 NW Orchard Avenue, Corvallis, OR 97330, USA; Department of Horticulture, Oregon State University, Corvallis, OR 97331, USA.
J Insect Physiol. 2017 May;99:86-94. doi: 10.1016/j.jinsphys.2017.04.001. Epub 2017 Apr 5.
In this study, we investigated the effects of non-nutritive sugars and sugar alcohols on the survivorship of spotted wing drosophila, Drosophila suzukii, and found erythritol and erythrose as potentially insecticidal to the fly. In a dose-dependent study, erythritol and erythrose significantly reduced fly longevity, with 100% mortality with 1, 0.5, 0.1 & 0.05M doses after feeding for 7days. When sucrose and erythritol solutions were provided separately to flies for 7days, there was no effect on survivorship regardless of erythritol concentrations. However, with a serial combination of sucrose and erythritol solutions, fly survivorship was significantly decreased for the same period. Also, the higher dose of erythritol regardless of the sucrose dose combined showed greater mortality. In a no-choice assay, D. suzukii ingested more erythritol than sucrose or water, indicating the fly continuously fed on erythritol for 72h. Also under no-choice conditions, erythritol and sucrose-fed flies gained more weight than water-fed flies. However, in two-choice assays, the amount of erythritol ingested was less than sucrose or water. Total sugar and glycogen levels among erythritol and erythrose-fed flies were significantly less than mannitol, sorbitol, xylitol, and sucrose-fed flies after 48h. This indicates that these two non-nutritive sugars can't be used a substrate for enzymes involved in sugar metabolism. Although the metabolism of erythritol and erythrose is unknown in insects, the mortality of D. suzukii flies ingesting these sugars might be caused by two potential physiological changes. The fly is starved by feeding of non-metabolizable erythritol and erythrose, or experiences abnormally high osmotic pressure in the hemolymph with erythritol molecules diffused from the midgut. Non-nutritive sugars might be used as an insecticide alone or combined with conventional or biological insecticides to enhance efficacy. If other sugar sources are present, a palatable sugar might be mixed with erythritol to elicit feeding.
在本研究中，我们调查了非营养性糖类和糖醇对铃木氏果蝇（Drosophila suzukii）存活的影响，发现赤藓糖醇和赤藓糖对该果蝇具有潜在的杀虫作用。在一项剂量依赖性研究中，赤藓糖醇和赤藓糖显著缩短了果蝇寿命，喂食7天后，1M、0.5M、0.1M和0.05M剂量的死亡率均达到100%。当分别向果蝇提供蔗糖和赤藓糖醇溶液7天时，无论赤藓糖醇浓度如何，对果蝇存活均无影响。然而，当蔗糖和赤藓糖醇溶液按顺序组合时，同期果蝇存活率显著降低。此外，无论蔗糖剂量如何，较高剂量的赤藓糖醇组合显示出更高的死亡率。在无选择试验中，铃木氏果蝇摄入的赤藓糖醇比蔗糖或水更多，表明果蝇连续72小时以赤藓糖醇为食。同样在无选择条件下，喂食赤藓糖醇和蔗糖的果蝇比喂食水的果蝇体重增加更多。然而，在双选试验中，摄入的赤藓糖醇量少于蔗糖或水。48小时后，喂食赤藓糖醇和赤藓糖的果蝇体内总糖和糖原水平显著低于喂食甘露醇、山梨醇、木糖醇和蔗糖的果蝇。这表明这两种非营养性糖类不能用作参与糖代谢的酶的底物。尽管昆虫中赤藓糖醇和赤藓糖的代谢尚不清楚，但摄入这些糖类的铃木氏果蝇死亡可能是由两种潜在的生理变化引起的。果蝇因摄入不可代谢的赤藓糖醇和赤藓糖而饥饿，或者由于赤藓糖醇分子从中肠扩散导致血淋巴渗透压异常升高。非营养性糖类可单独用作杀虫剂，或与传统或生物杀虫剂联合使用以提高效果。如果存在其他糖源，可将美味的糖与赤藓糖醇混合以诱导取食。
