Hoy Marjorie A, Jeyaprakash A
Department of Entomology and Nematology, University of Florida, PO Box 110620, Gainesville, FL 32611, USA.
Exp Appl Acarol. 2008 Dec;46(1-4):329-47. doi: 10.1007/s10493-008-9185-3. Epub 2008 Aug 12.
Metaseiulus (= Typhlodromus or Galendromus) occidentalis (Nesbitt) (Acari: Phytoseiidae) is an effective natural enemy of pest mites in a variety of crops around the world, although it is considered to be endemic in the western USA. A broad understanding of much of its biology, ecology, behavior, and genetics has been obtained over the past 60 years, but the role(s) symbionts play, which includes pathogens and other microorganisms, remains to be resolved fully. Until molecular tools became available, analysis methods were limited primarily to microscopic observations; some viruses and rickettsia-like organisms were observed infecting 'diseased' M. occidentalis, but it is not clear which one(s) was the causal agent(s) of the disease(s). Subsequent to the development of the polymerase chain reaction (PCR) and genome sequencing, we identified putative gut symbionts and reproductive tract symbionts in M. occidentalis, as well as a microsporidian pathogen. A new phylogenetic analysis of the Bacteroidetes-Flavobacterium group suggests the unnamed Bacteroidetes in M. occidentalis is associated with the digestive tract. However, much of our current information about the role these microorganisms play in the biology of M. occidentalis is based on correlation, lacking the strength of fulfilling Koch's postulates. We also currently lack any knowledge of the importance of these microorganisms under field conditions. In the future, it should be possible to learn what role(s) these organisms play in the biology of this important predator using metagenomics approaches to analyze the transcriptome and to determine their relative abundance within their hosts with the quantitative PCR. We have just begun to resolve these relationships.
西方盲走螨（Metaseiulus (= Typhlodromus or Galendromus) occidentalis (Nesbitt)，蜱螨亚纲：植绥螨科）是世界上多种作物中害螨的有效天敌，尽管它被认为原产于美国西部。在过去60年里，人们对其生物学、生态学、行为学和遗传学有了广泛的了解，但共生体（包括病原体和其他微生物）所起的作用仍有待全面解决。在分子工具出现之前，分析方法主要限于显微镜观察；观察到一些病毒和立克次氏体样生物感染“患病”的西方盲走螨，但不清楚哪种是致病病原体。在聚合酶链反应（PCR）和基因组测序技术发展之后，我们在西方盲走螨中鉴定出了假定的肠道共生体和生殖道共生体，以及一种微孢子虫病原体。对拟杆菌-黄杆菌组的新系统发育分析表明，西方盲走螨中未命名的拟杆菌与消化道有关。然而，我们目前关于这些微生物在西方盲走螨生物学中作用的许多信息都是基于相关性，缺乏符合科赫法则的有力证据。我们目前也不清楚这些微生物在田间条件下的重要性。未来，利用宏基因组学方法分析转录组，并通过定量PCR确定它们在宿主中的相对丰度，应该有可能了解这些生物在这种重要捕食者的生物学中所起的作用。我们才刚刚开始解决这些关系。
