Populationsbiologie zweier gefährdeter sozialparasitischer Ameisenarten

社会性寄生蚂蚁利用其他蚁群的劳动力来养育自己的后代。自达尔文（Darwin）以来，在篡夺宿主社会、消灭宿主女王、在奴隶掠夺期间补充宿主工人以及社会性寄生虫与宿主之间的共同进化过程中，这些令人着迷的行为一直吸引着研究人员。由于对宿主的破坏性影响，大多数群居寄生虫极为罕见，几乎都被世界自然保护联盟和国家红色名录列为威胁物种。然而，相对较少的努力，以确定这些有趣的，罕见的蚂蚁的实际保护状况。研究了两个生活史截然不同的近缘类群，即活跃的奴隶制造者Myrmoxenus ravouxi和退化的奴隶制造者M. kraussei的种群和群体结构。Myrmoxenus ravouxi是在德国发现的少数制造奴隶的蚂蚁之一。据报道，在德国的几个干热地区，有一些分散、密集的Temnothorax蚂蚁种群（Seifert 1995,2007），中欧各地都认为Temnothorax蚂蚁濒临灭绝，甚至接近灭绝。蚁后在一次交配飞行中分散并交配后发现了新的殖民地，工蜂从邻近的寄主巢穴中掠夺蛹，以增加其殖民地中寄主工蜂的数量。来自意大利北部和法国南部的M. kraussei是一个同样罕见的，堕落的奴隶制造者，也就是说，它的女王专注于生产性动物，而生产的工人太少，无法积极地掠夺奴隶。雌性在母巢中与它们的兄弟交配。从它们不同的生活史来看，我们认为这两种社会寄生虫具有不同的种群结构、不同的灭绝风险以及对各自寄主种群的不同影响。因此，我们打算通过微卫星基因分型和线粒体I和核基因测序来分析目前已知的两个物种的几个种群及其Temnothorax宿主的遗传结构，以获得群体结构和种群动态（局部遗传变异，种群之间的基因流动，近亲繁殖的程度和影响以及宿主利用模式）的信息。这些数据将有助于澄清，Myrmoxenus和其他具有类似生活史的造奴蚁种群是否确实面临灭绝的高度威胁，或者是否比之前认为的更强大。

Socially parasitic ants exploit the workforce of societies of other ant species to rear their own offspring. The fascinating behavior during the usurpation of host societies, the elimination of the host queen, the replenishment of host workers during slave raids, and the coevolution between social parasites and their hosts has attracted researchers ever since Darwin. Because of the destructive effect on their hosts, most social parasites are extremely rare, and almost all are listed as threatened by IUCN and national red lists. Nevertheless, comparatively little effort has been made to determine the actual conservation status of these interesting, rare ants. We intend to investigate the population and colony structure of two closely related taxa with notably different life histories, the active slave-maker Myrmoxenus ravouxi and the degenerate slave-maker M. kraussei. Myrmoxenus ravouxi is one of the few slave-making ants found in Germany. It has been reported from a few scattered, dense populations of Temnothorax ants in several xerothermic areas in Germany (Seifert 1995, 2007) and is considered to be endangered or even close to extinction everywhere in Central Europe. Queens found new colonies after dispersing and mating during a nuptial flight and workers pillage pupae from neighboring host nests to increase the number of host workers in their colonies. M. kraussei is a similarly rare, degenerate slave-maker from Northern Italy and Southern France, i.e., its queens focus on the production of sexuals and produce too few workers for active slave-raiding. Female sexuals mate with their brothers in the maternal nest. From their different life histories we expect the two social parasites to have different population structures, different extinction risks, and different impact on the respective host populations. We therefore intend to analyze the genetic structure of several of the presently known populations of both species and their Temnothorax hosts by microsatellite genotyping and sequencing of mitochondria I and nuclear genes to obtain information on colony structure and population dynamics (local genetic variability, gene flow between populations, the extent and effect of inbreeding, and the pattern of host utilization). The data shall help to clarify whether populations of Myrmoxenus and other slave-making ants with similar life history are indeed highly threatened by extinction or more robust than previously thought.