Exploiting chemical ecology to manage hyperparasitoids in biological control of arthropod pests

Insect hyperparasitoids are fourth trophic level organisms that commonly occur in terrestrial food webs, yet they are relatively understudied. These top‐carnivores can disrupt biological pest control by suppressing the populations of their parasitoid hosts, leading to pest outbreaks, especially in confined environments such as greenhouses where augmentative biological control is used. There is no effective eco‐friendly strategy that can be used to control hyperparasitoids. Recent advances in the chemical ecology of hyperparasitoid foraging behavior have opened opportunities for manipulating these top‐carnivores in such a way that biological pest control becomes more efficient. We propose various infochemical‐based strategies to manage hyperparasitoids. We suggest that a push‐pull strategy could be a promising approach to ‘push’ hyperparasitoids away from their parasitoid hosts and ‘pull’ them into traps. Additionally, we discuss how infochemicals can be used to develop innovative tools improving biological pest control (i) to restrict accessibility of resources (e.g. sugars and alternative hosts) to primary parasitoid only or (ii) to monitor hyperparasitoid presence in the crop for early detection. We also identify important missing information in order to control hyperparasitoids and outline what research is needed to reach this goal. Testing the efficacy of synthetic infochemicals in confined environments is a crucial step towards the implementation of chemical ecology‐based approaches targeting hyperparasitoids. © 2019 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

饲用墨西哥玉米生长特性及其营养成分含量的研究

随着养殖业畜群结构的调整,农区草食动物饲养量的增加,种植优质、高效牧草是当前人们所迫切需要的.试验就饲用墨西哥玉米Euchlaena mexicana的生长特性及其营养成分含量进行研究,结果表明:饲用墨西哥玉米适宜在冀东农区种植,该作物具有较强的分蘖性能,适于多次刈割,每茬次刈割鲜草质量400～700 g/株,随着刈割茬次的增加,草产量大幅度增加,可采食的优质草量增多,纤维化程度大大下降,可消化养分量增加,种草的效益随刈割茬次显著的上升.墨西哥玉米干物质、粗蛋白、粗脂肪、粗纤维、粗灰分、钙、磷和胡萝卜素的含量都优于其他禾本科牧草.刈割茬次间各种营养成分差异不大,非常适合青饲,经饲喂的各种草食动物,适口性好,采食率高.     

Observations on the attachment of a piscine gill parasitic ergasilid (Crustacea: Copepoda)

The attachment of the piscine gill parasite, Ergasilus mirabilis Oldewage & van As, 1987 is described by means of scanning electron microscopy and light microscopy. A variety of sensory structures occur on and around the host contact surface of the parasite and proliferation of gill tissue occurs at the site of attachment. It would appear that this proliferation of host tissue results from the feeding behaviour of the parasite rather than the actual attachment thereof.     

云南野生动物园食草动物区植物景观配置改造策略

以云南野生动物园食草动物区为研究对象,在调查分析基础上,依据动物的生活习性将园区划分为林区、草原区、草甸和荒漠区、水域区4个功能区。阐述植物景观在野生动物园展区中的功能转换,遵循以动物为主体、以模拟生境为核心的景观改造方略,并结合游人游览和观赏需求,对云南野生动物园食草动物区的4个功能区提出具体的植物景观配置改造方案。     

道县发展草食动物的资源与潜力分析

介绍了道县草食动物养殖资源状况,对草食动物养殖潜力进行综合分析。结果表明,道县的气候、地理环境、饲料资源丰富,当前可用于饲养草食动物的饲料量为51.00万t,可饲养338 550头牛,在目前159 000头的基础上可再增加179 550头;潜在饲料量为26.25万t,可饲养174 320头牛。     

动物园草食动物肠道寄生虫感染情况和治疗效果回顾性分析

应用离心沉淀法和饱和蔗糖溶液漂浮法对郑州市动物园22种草食动物共88份粪便样品进行调查。寄生虫总感染率为19.31%,球虫、线虫和鞭虫感染率分别为7.95%、12.50%和2.27%。数据分析显示,寄生虫感染率逐年递减,比2003年降低了39.95%,感染程度也明显减轻。表明该园防控措施具有良好效果,为今后动物园制定有关寄生虫病防治措施提供了参考依据。     

乌桕对南方根结线虫与地上不同食性昆虫互作的光合生理响应

本文通过比较乌桕对两种地上不同食性昆虫(专食性癞皮夜蛾、广食性斜纹夜蛾)与南方根结线虫互作的光合生理响应,分析不同空间植食性生物间的互作关系及植物的响应机制。结果表明:无南方根结线虫胁迫下,2种地上不同食性昆虫对乌桕的净光合速率(P_n)、气孔导度(G_s)及胞间CO_2浓度(C_i)的影响与对照组无显著差异;而南方根结线虫胁迫下,2种地上昆虫显著降低了乌桕G_s及C_i。其中,与对照组及癞皮夜蛾处理组相比,南方根结线虫与斜纹夜蛾的共同胁迫显著降低了乌桕P_n、G_s及C_i。此外,斜纹夜蛾为害增加了乌桕叶绿素含量,南方根结线虫胁迫降低了叶绿素含量。因此,南方根结线虫与斜纹夜蛾间形成一种加性效应,并对乌桕光合生理产生了拮抗效应,而这种效应在南方根结线虫与癞皮夜蛾间并不显著。由此可见,乌桕对地上-地下植食性生物胁迫形成不足补偿机制,且具体的响应机制与植食性生物的食性相关。     

三江源区高寒草地营养承载力时空格局

草畜平衡管理是草地可持续发展的有效途径之一，而草地承载力的核定是草畜平衡管理的基础和前提。本文基于野外调查和遥感估算方法，分析了三江源区可食牧草和粗蛋白产量的季节变化，并核算了可食牧草和粗蛋白的理论承载力。结果表明：三江源区高寒草地返青期、盛草期和枯草期可食牧草平均产量分别为20.84，89.86和50.27 g·m^-2；可食牧草承载力分别为1.18，2.21和0.69（标准羊单位·ha^-1，Sheep unit·ha^-1，SHU·ha^-1）；平均粗蛋白产量分别为2.63，10.11和1.94 g·m^-2；在维持基本代谢或45 kg标准羊体重不变情况下，平均粗蛋白理论承载力分别为8.30，4.98，0.89 SHU·ha^-1，和4.76，2.85，0.51 SHU·ha^-1。依据粗蛋白承载力高于可食牧草承载力及东部和东南部向西部和西北部递减的分布格局，建议在东部农牧交错区合理利用天然草地，适度开发耕地，籽实体农业转向营养体农业，实现东部和中部地区资源配置、优势互补的耦合发展模式。