Southern rootworm (Diabrotica undecimpunctata howardi) affects several plants such as soybean, sorghum, wheat, cucumber, alfalfa, cucurbits and it is most damaging to corn and peanuts. The pheromone based “attract an...Southern rootworm (Diabrotica undecimpunctata howardi) affects several plants such as soybean, sorghum, wheat, cucumber, alfalfa, cucurbits and it is most damaging to corn and peanuts. The pheromone based “attract and kill” strategy is one of the powerful ways to control pest population. To address our key objective of the practical utility of the synthetic pheromone, we have developed a simple synthetic strategy to produce gram scale southern corn rootworm pheromone in nine simple steps starting from S-Citronellol. The present strategy takes advantage of the existing chiral center of commercially available S-Citronellol. To get the basic carbon skeleton of the pheromone, the main step in the synthetic strategy is coupling of aliphatic units through Wittig reaction. The phosphonium salt from a non-functionalized aliphatic bromide followed by Wittig reaction improved the overall yield in the multistep synthesis of this pheromone. The large-scale production of pheromone enabled us to test it in the field.展开更多
十一星瓢虫Coccinella undecimpunctata Linnaeus是青海省柴达木地区的一种重要捕食性天敌。为明确其对枸杞棉蚜Aphis gossypii Glover和枸杞木虱Poratrioza sinica Yang et Li.两种主要枸杞害虫的嗜好性,开展了捕食选择性试验,发现当...十一星瓢虫Coccinella undecimpunctata Linnaeus是青海省柴达木地区的一种重要捕食性天敌。为明确其对枸杞棉蚜Aphis gossypii Glover和枸杞木虱Poratrioza sinica Yang et Li.两种主要枸杞害虫的嗜好性,开展了捕食选择性试验,发现当两种害虫共存时,瓢虫成虫更喜食棉蚜。为进一步探究十一星瓢虫对枸杞棉蚜的捕食能力,测定了瓢虫各龄幼虫和成虫在不同棉蚜密度下的捕食量、寻找效应以及种内干扰、自身密度对捕食作用的影响。结果表明:十一星瓢虫各虫态对棉蚜的捕食功能反应均符合Holling-Ⅱ功能反应模型,种内干扰、自身密度对捕食量的影响分别符合Hassell干扰效应模型和Watt模型。十一星瓢虫1~4龄幼虫及成虫对枸杞棉蚜的日最大理论捕食量分别为18.94、44.29、81.57、145.27和126.48头;在一定空间、相同瓢蚜比条件下,瓢虫同一虫态个体间存在种内干扰效应,以1龄幼虫受干扰最大,干扰常数为1.1803。此外,瓢虫自身密度对其捕食作用产生一定的影响,4龄幼虫和成虫影响更为明显,竞争参数分别为0.7948和0.6848。本研究可为今后更高效地利用青海高原本地十一星瓢虫资源提供理论依据。展开更多
文摘Southern rootworm (Diabrotica undecimpunctata howardi) affects several plants such as soybean, sorghum, wheat, cucumber, alfalfa, cucurbits and it is most damaging to corn and peanuts. The pheromone based “attract and kill” strategy is one of the powerful ways to control pest population. To address our key objective of the practical utility of the synthetic pheromone, we have developed a simple synthetic strategy to produce gram scale southern corn rootworm pheromone in nine simple steps starting from S-Citronellol. The present strategy takes advantage of the existing chiral center of commercially available S-Citronellol. To get the basic carbon skeleton of the pheromone, the main step in the synthetic strategy is coupling of aliphatic units through Wittig reaction. The phosphonium salt from a non-functionalized aliphatic bromide followed by Wittig reaction improved the overall yield in the multistep synthesis of this pheromone. The large-scale production of pheromone enabled us to test it in the field.
文摘十一星瓢虫Coccinella undecimpunctata Linnaeus是青海省柴达木地区的一种重要捕食性天敌。为明确其对枸杞棉蚜Aphis gossypii Glover和枸杞木虱Poratrioza sinica Yang et Li.两种主要枸杞害虫的嗜好性,开展了捕食选择性试验,发现当两种害虫共存时,瓢虫成虫更喜食棉蚜。为进一步探究十一星瓢虫对枸杞棉蚜的捕食能力,测定了瓢虫各龄幼虫和成虫在不同棉蚜密度下的捕食量、寻找效应以及种内干扰、自身密度对捕食作用的影响。结果表明:十一星瓢虫各虫态对棉蚜的捕食功能反应均符合Holling-Ⅱ功能反应模型,种内干扰、自身密度对捕食量的影响分别符合Hassell干扰效应模型和Watt模型。十一星瓢虫1~4龄幼虫及成虫对枸杞棉蚜的日最大理论捕食量分别为18.94、44.29、81.57、145.27和126.48头;在一定空间、相同瓢蚜比条件下,瓢虫同一虫态个体间存在种内干扰效应,以1龄幼虫受干扰最大,干扰常数为1.1803。此外,瓢虫自身密度对其捕食作用产生一定的影响,4龄幼虫和成虫影响更为明显,竞争参数分别为0.7948和0.6848。本研究可为今后更高效地利用青海高原本地十一星瓢虫资源提供理论依据。
