The ant odometer: stepping on stilts and stumps

Desert ants, Cataglyphis, navigate in their vast desert habitat by path integration. They continuously integrate directions steered (as determined by their celestial compass) and distances traveled, gauged by as-yet-unknown mechanisms. Here we test the hypothesis that navigating ants measure distances traveled by using some kind of step integrator, or "step counter." We manipulated the lengths of the legs and, hence, the stride lengths, in freely walking ants. Animals with elongated ("stilts") or shortened legs ("stumps") take larger or shorter strides, respectively, and concomitantly misgauge travel distance. Travel distance is overestimated by experimental animals walking on stilts and underestimated by animals walking on stumps.     

Traditional knowledge and rationale for weaver ant husbandry in the Mekong delta of Vietnam

The weaver ant, Oecophylla smaragdina Fabricius (Hymenoptera: Formicidae), has long been known as perhaps the first example of human manipulation of a natural predator population to enhance the natural biological control of insect pests. The practice of ant husbandry in Vietnamese citrus orchards and the knowledge associated with the use of weaver ants in the Mekong delta are described. In contrast to other regions of Asia, where weaver ants are noted for their role in the protection of citrus from insect damage, citrus farmers in the Mekong delta explain the benefits of ant husbandry in terms of an improvement in fruit quality, likened to the influence of fertilizers, that occurs in direct response to excretory products deposited by the weaver ants as they patrol the fruit. A series of tests, carried out in 1993–94, rated the external shine, sweetness, juiciness, and overall appeal, as characteristics of fruit quality, for paired comparisons of sweet orange, mandarin, and pummelo fruit that had been grown in the presence of weaver ants or from which ants had been excluded. The tests indicate a strong influence of the presence of the weaver ant on external shine, juiciness, and overall appeal for each of the citrus fruits, but particularly for mandarin. The significance of these results and ant husbandry practices in the Mekong delta are discussed in relation to the development of citrus production in Vietnam.     

Postsecretory hydrolysis of nectar sucrose and specialization in ant/plant mutualism

Obligate Acacia ant plants house mutualistic ants as a defense mechanism and provide them with extrafloral nectar (EFN). Ant/plant mutualisms are widespread, but little is known about the biochemical basis of their species specificity. Despite its importance in these and other plant/animal interactions, little attention has been paid to the control of the chemical composition of nectar. We found high invertase (sucrose-cleaving) activity in Acacia EFN, which thus contained no sucrose. Sucrose, a disaccharide common in other EFNs, usually attracts nonsymbiotic ants. The EFN of the ant acacias was therefore unattractive to such ants. The Pseudomyrmex ants that are specialized to live on Acacia had almost no invertase activity in their digestive tracts and preferred sucrose-free EFN. Our results demonstrate postsecretory regulation of the carbohydrate composition of nectar.     

从油菜6个物种的核型分析追溯其进化和关系

本文对欧洲油菜(B.napuo)和日本油菜(B.napella)的核型进行了比较分析。结果表明,它们之间差异较大,为欧洲油菜和日本油菜区分为两个种或种以下的变种的论点提供了细胞遗传学依据。     

Treehoppers transfer parental care to ants: a new benefit of mutualism

Female treehoppers (Publilia reticulata Van Duzee) modify their parental care behavior in the presence of ants. Females with untended young remain with their original brood, but females from ant-tended colonies readily desert their first brood and produce additional clutches. Care by female treehoppers, in the absence of ants, increases the probability that a colony will produce some survivors, but ant attendance greatly increases the number of surviving nymphs.     

Ancient tripartite coevolution in the attine ant-microbe symbiosis

The symbiosis between fungus-growing ants and the fungi they cultivate for food has been shaped by 50 million years of coevolution. Phylogenetic analyses indicate that this long coevolutionary history includes a third symbiont lineage: specialized microfungal parasites of the ants' fungus gardens. At ancient levels, the phylogenies of the three symbionts are perfectly congruent, revealing that the ant-microbe symbiosis is the product of tripartite coevolution between the farming ants, their cultivars, and the garden parasites. At recent phylogenetic levels, coevolution has been punctuated by occasional host-switching by the parasite, thus intensifying continuous coadaptation between symbionts in a tripartite arms race.     

Coevolved crypts and exocrine glands support mutualistic bacteria in fungus-growing ants

Attine ants engage in a quadripartite symbiosis with fungi they cultivate for food, specialized garden parasites, and parasite-inhibiting bacteria. Molecular phylogenetic evidence supports an ancient host-pathogen association between the ant-cultivar mutualism and the garden parasite. Here we show that ants rear the antibiotic-producing bacteria in elaborate cuticular crypts, supported by unique exocrine glands, and that these structures have been highly modified across the ants' evolutionary history. This specialized structural evolution, together with the absence of these bacteria and modifications in other ant genera that do not grow fungus, indicate that the bacteria have an ancient and coevolved association with the ants, their fungal cultivar, and the garden parasite.     

基于认知程度评估的红火蚁 管理策略与方式探讨

采用问卷调查的方法对南沙区132 个社区/村当地居民对红火蚁认知程度进行调查。结果发现、南沙区 居民对红火蚁的了解程度较高、其中65.2%居民知道红火蚁;对红火蚁的了解途径中、野亲眼所见冶所占比例最高、为 57.78%、其次是从电视上得知、为14.43%;86.84%居民所在地区发现有红火蚁、90.93%居民周围有人知道红火蚁。在 发现红火蚁后、52.35%居民会向相关部门反映、38.01%居民会使用工具进行破坏;68.78%居民3 年前就已经听说当 地有红火蚁发生;48.08%居民认为红火蚁入侵对人身健康产生影响;59.59%居民被红火蚁叮咬过、且86.32%居民会 有痛痒、红肿、脓包的症状;69.50%居民在被叮咬后知道处理方法、其中53.88%居民会涂抹药膏、30.53%会去医;就 医;62.09%居民会关心入侵生物相关的信息;56.37%居民了解红火蚁相关工作内容;89.95%居民对红火蚁的宣传、防 治工作感到基本满意;在红火蚁相关工作中、37.47%居民建议应该加强防控力度、21.98%居民认为应该加强宣传。通 过调查所反映的问题、提出解决的方法和建议。     

广东红火蚁多个生境中诱饵对蚂蚁诱集作用比较

研究了荔枝园、荒草地和绿化带3种红火蚁Solenopsis invicta入侵生境中火腿肠、沙丁鱼、黄粉虫和蜂蜜4种诱饵及其组合对蚂蚁的引诱作用.结果表明,火腿肠、火腿肠 蜂蜜、沙丁鱼 蜂蜜这3种诱饵不仅能诱到较多的蚂蚁种类,也能诱到较多的蚂蚁数量;红火蚁对火腿肠的趋性最强,而火腿肠诱集其他蚂蚁的数量最少;通过对3种生境中不同诱饵诱集其他蚂蚁数量占所诱蚂蚁总数的百分比的分析发现,蜂蜜和加蜂蜜的诱饵诱集其他蚂蚁的数量最多;综合多方面的因素,在红火蚁发生区进行蚂蚁群落调查,火腿肠 蜂蜜和沙丁鱼 蜂蜜是最好的诱饵选择.     

Explaining the abundance of ants in lowland tropical rainforest canopies

The extraordinary abundance of ants in tropical rainforest canopies has led to speculation that numerous arboreal ant taxa feed principally as "herbivores" of plant and insect exudates. Based on nitrogen (N) isotope ratios of plants, known herbivores, arthropod predators, and ants from Amazonia and Borneo, we find that many arboreal ant species obtain little N through predation and scavenging. Microsymbionts of ants and their hemipteran trophobionts might play key roles in the nutrition of taxa specializing on N-poor exudates. For plants, the combined costs of biotic defenses and herbivory by ants and tended Hemiptera are substantial, and forest losses to insect herbivores vastly exceed current estimates.     

Tournaments and slavery in a desert ant

Many species of ants engage in physical fighting when territorial borders are challenged. In contrast, colonies of the honeypot ant species Myrmecocystus mimicus conduct ritualized tournaments, in which hundreds of ants perform highly stereotyped display fights. Opposing colonies summon their worker forces to the tournament area by means of an alarm-recruitment system. When one colony is considerably stronger than the other, the tournament quickly ends, and the weaker colony is raided and its ants "enslaved." This is the first example of intraspecific slavery recorded in ants.     

4种猛蚁的巢穴结构及巢内生物

敏捷厚结猛蚁Pachycondyla astuta Smith、聚纹双刺猛蚁Diacamma rugosum(Le Guillou)、横纹齿猛蚁Odonto-ponera transversa(Smith)和猎镰猛蚁Harpegnathos venator(Smith)是我国东部和南部地区比较常见的猛蚁,可捕食林木白蚁,是一类潜在的天敌昆虫.通过挖巢的方法对这4种猛蚁的筑巢环境、巢穴结构和巢内生物进行了研究.结果表明,4种猛蚁的巢穴均为地下巢,多建在橡胶林、荔枝林等林间空地;结构比较简单,深度一般不超过0.6 m,巢室仅有几个至数十个,在土壤中分布无规则至分层排列.巢穴内部或周围常可见到膜翅目、等翅目昆虫以及土壤小型多足类和等足类动物.     

Phylogeny of the ants: diversification in the age of angiosperms

We present a large-scale molecular phylogeny of the ants (Hymenoptera: Formicidae), based on 4.5 kilobases of sequence data from six gene regions extracted from 139 of the 288 described extant genera, representing 19 of the 20 subfamilies. All but two subfamilies are recovered as monophyletic. Divergence time estimates calibrated by minimum age constraints from 43 fossils indicate that most of the subfamilies representing extant ants arose much earlier than previously proposed but only began to diversify during the Late Cretaceous to Early Eocene. This period also witnessed the rise of angiosperms and most herbivorous insects.     

Host Finding by Odor in the Myrmecophilic Beetle Atemeles pubicollis Bris. (Staphylinidae)

The beetle Atemeles publicollis orients to the odor of its host ants by positive anemotaxis and osmoclinotaxis. The chemical response changes with age of the beetles. After hatching they are attracted by Myrmica odors, and, after hibernating, by Formica odors.     

The evolution of agriculture in ants

Cultivation of fungi for food by fungus-growing ants (Attini: Formicidae) originated about 50 million years ago. The subsequent evolutionary history of this agricultural symbiosis was inferred from phylogenetic and population-genetic patterns of 553 cultivars isolated from gardens of "primitive" fungus-growing ants. These patterns indicate that fungus-growing ants succeeded at domesticating multiple cultivars, that the ants are capable of switching to novel cultivars, that single ant species farm a diversity of cultivars, and that cultivars are shared occasionally between distantly related ant species, probably by lateral transfer between ant colonies.     

Territorial strategies in ants

Several features in social insects, particularly in ants, make the behavioral organization of territoriality considerably more complex than that of solitary animals. The establishment and maintenance of territories are based on a division of labor and a complex communication system. The analyses of territorial strategies in ants comprise the study of the design and spatiotemporal structure of the territory, as well as the social mechanisms through which the insect society pursues its territorial strategy. The geometric and behavioral organization of the absolute territories of the African weaver ants (Oecophylla longinoda) and harvester ants (Pogonomyrmex), and of the "spatiotemporal territories" of honey ants (Myrmecocystus mimicus) are described, and simple cost-benefit models are developed to illustrate the economic defensibility of each type of territory.     

Evolutionary history of the symbiosis between fungus-growing ants and their fungi

The evolutionary history of the symbiosis between fungus-growing ants (Attini) and their fungi was elucidated by comparing phylogenies of both symbionts. The fungal phylogeny based on cladistic analyses of nuclear 28S ribosomal DNA indicates that, in contrast with the monophyly of the ants, the attine fungi are polyphyletic. Most cultivated fungi belong to the basidiomycete family Lepiotaceae; however, one ant genus, Apterostigma, has acquired a distantly related basidiomycete lineage. Phylogenetic patterns suggest that some primitive attines may have repeatedly acquired lepiotaceous symbionts. In contrast, the most derived attines have clonally propagated the same fungal lineage for at least 23 million years.     

地方政府投融资平台投资效益综合评价研究——基于熵权法与因子分析法

孔子的“正名”说并非无源之水,而是发端于前孔子时代人们对于“名”的深入思考。“名”这个观念受到重视与礼乐文化密切相关,由此,“名”的问题展现为两条进路：一、与名分义相关的政治进路;二、与名声义相关的道德进路,孔子继承并发展了这两个方面。澄清了这个过程,就会看到,孔子正名思想不能简单地看做中国古代逻辑学的起源,而应当看作儒家内圣外王之义理规模的发生地。     

Neuronal circuits: an evolutionary perspective

To understand neural circuits completely, it is necessary to know not only how they work, but also why they work that way. Answers to the latter question have been almost teleological in their assumption of optimal design. However, close examination of certain systems has revealed features that apparently lack adaptive value. Their existence can be understood only if the evolution of these circuits is considered and, in particular, how nonadaptive determinants have guided that evoluton.