Invasive goldenrods affect abundance and diversity of grassland ant communities (Hymenoptera: Formicidae)

Goldenrods (Solidago sp.) are currently one of the most invasive plant species in Central Europe. They threaten abandoned semi-natural wet grasslands which are extremely vulnerable to plant succession and invasions. We assessed whether Solidago invasion affects ants, keystone organisms essential to proper ecosystem functioning and to the existence of myrmecophilous Phengaris butterflies. Ten meadows containing 60 plots with and without goldenrods were studied. We found a strong, negative dependence between the presence of goldenrod cover and the number of ant nests (more than 50 % reduction compared to control) as well as the number of species, and changes in species composition. Myrmica ants, essential hosts for Phengaris larvae, were among the most affected species by goldenrod invasion. Immediate action should be undertaken for restoration and maintenance of biodiversity hotspots affected by goldenrod invasion.     

Strategies for controlling the ghost ant,Tapinoma melanocephalum (Hymenoptera: Formicidae) with liquid bait

The ghost ant, Tapinoma melanocephalum (F.), is a household pest and a considerable nuisance. The aim of this study is to demonstrate the toxicity and control efficacy of boric acid in liquid bait against queen and worker ghost ants. The LT₅₀ values for workers fed with 0.5%–2.5% boric acid and 2% chicken peptone in 20% sucrose water solutions were 4.3–2.4 days. The lethal times (LT₅₀ = 5.2–7.6 days) for queen ghost ants fed with various concentrations of a boric acid solution depended on the feeding behavior of the queens. The high boric acid (4%) content solutions were not repellent to the ghost ant workers. The liquid bait formulation of 1% boric acid, which caused a 100% worker, brood, and queen population reduction in 4, 4, and 5 weeks, respectively, was significantly more effective than the solid bait formulation containing the same concentration (p ≦ 0.05). The simulation tests involved using chicken peptone and sucrose as the attractant, and colonies were provided an alternate food source (20% sucrose solution and dog food) to achieve a more accurate assessment of bait acceptability in screening for the efficacy of the liquid boric acid bait. The control efficiency attained 99.9% in week 4. The results demonstrated that liquid bait, containing 2% chicken peptone, 20% sucrose as a food attractant, and 1% boric acid as the toxin, is efficient and highly recommended for ghost ant control.     

Patterns of DNase I sensitivity in the chromosomes of the ant Tapinoma nigerrimum (Hymenoptera,Formicidae)

We have analysed the patterns of DNase I/nick translation in the chromosomes of Tapinoma nigerrimum. The results show a non-uniform DNase I sensitivity in different chromosome domains. The hypersensitivity appears to be specially concentrated at both the NOR and the distal regions. The resemblance to and differences from the situation in other animal species, in which active genes are DNase I hypersensitive, are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Population growth of Aphis gossypii and Myzus persicae (Hemiptera: Aphididae) in the presence of Linepithema humile and Tapinoma sessile (Hymenoptera: Formicidae)

Invasive ant species can have dramatic impacts on native ants, through direct predation and by usurping common resources. Most invasive ants and many native ants use honeydew, produced by phloem-sucking hemipterans. Because colonies of invasive ants can become very large after establishment, these ants may facilitate greater hemipteran trophobiont population growth compared with their sympatric native ant counterparts. We examined the population growth of an aphid mutualist, Aphis gossypii, and a nonmutualist, Myzus persicae, exposed to two Dolichoderine ants, Linepithema humile, a globally widespread invasive species, and Tapinoma sessile, a widespread co-occurring native ant, in North America in an enemy-free laboratory study. L. humile worker foraging activity was at least twice that of T. sessile, and populations of the myrmecophile, A. gossypii, were greater when exposed to L. humile than T. sessile, possibly caused, in part, by more frequent encounters with L. humile. L. humile ignored M. persicae when A. gossypii was absent, whereas T. sessile preyed on it. Both ant species preyed on M. persicae when A. gossypii was also present. This suggested that both ants may assess nutritional gains from aphid species (i.e., honeydew versus body tissue), eliminating less productive aphids competing for host plant space. Through their impact on populations of hemipteran mutualists, we suggest that colonies of L. humile and perhaps other invasive ants may acquire more honeydew than native ants, thereby fueling colony growth that leads to numerical dominance and widespread success in introduced environments.     

Interactions between the ant Tapinoma nigerrimum (Hymenoptera: Formicidae) and the main natural enemies of the vine and citrus mealybugs (Hemiptera: Pseudococcidae)

Honeydew-excreting hemipterans, such as mealybug pests, can be protected from their natural enemies by tending ants in return for honeydew, thereby compromising the aims of biological control. In this respect, antagonistic interactions between the ant Tapinoma nigerrimum, native to the Mediterranean basin, and the main natural enemies of both the vine mealybug (VMB), Planococcus ficus, and the citrus mealybug (CM), Planococcus citri, were assessed in laboratory conditions. Parasitism of vine and CMs by their respective parasitoids, Anagyrus sp. nr. pseudococci and Leptomastix dactylopii, was negatively affected by the ant T. nigerrimum. Similarly, T. nigerrimum was shown to significantly disrupt the predatory potential of ladybird larvae, Cryptolaemus montrouzieri, when foraging on host CMs. By contrast, the presence of the ant did not negatively influence the predatory activity of C. montrouzieri adults when feeding on CMs. Consequently, the encyrtid parasitoids A. sp. nr. pseudococci and L. dactylopii and the larval stage of the predator C. montrouzieri may be considered as T. nigerrimum-sensitive, whereas the adults of C. montrouzieri may be regarded as T. nigerrimum-resistant predators. Accordingly, the ant T. nigerrimum constitutes a threat to the biological control of mealybugs by either the encyrtids A. sp. nr. pseudococci and L. dactylopii or the larval stage of the ladybird C. montrouzieri. Hence, adequate control of T. nigerrimum is highly recommended before any release of these mealybugs' natural enemies.     

Comparative ultrastructure of ant spermatozoa (Formicidae: Hymenoptera)

Mature spermatozoa from spermathecae of founding queens were obtained from 5 species of ants, representing the major subfamilies Myrmicinae (Acromyrmex versicolor, Crematogaster sp.) and Dolichoderinae (Tapinoma sessile, Conomyrma insana, Conomyrma wheeleri). The ultrastructure of ant spermatozoa has many features in common with that of higher insects and is similar to that of other Hymenoptera. Structural similarities to spermatozoa of other Hymenoptera include an acrosome containing an internal rod that extends into the nucleus, two elongate mitochondrial derivatives, a centriolar adjunct, and an axonemal arrangement of 9 + 9 + 2 that includes well-developed coarse, or accessory, tubules. Spermatozoa obtained from A. versicolor, a species that is known to store and utilize viable sperm from this supply for over 10 years, show greater development of the mitochondrial derivatives than do the other species. The most distinctive feature of ant spermatozoa in comparison to other Hymenoptera is the large size of the centriolar adjunct relative to the other organelles. The centriolar adjunct is located posterior to the nucleus, anterior to the mitochondrial derivatives, and opposite the axoneme.     

Revision of the dolichoderine ant genus Turneria (Hymenoptera: Formicidae)

Abstract. The Australasian ant genus Turneria is revised. T.bidentata Forel, T.dahlii Forel and T.pacifica Mann are redescribed and a lectotype designated for T.bidentata. T.frenchi Forel is transferred to Stigmacros (comb.n.), and T.butteli Forel is transferred to Iridomyrmex (comb.n.). Three new species, T.arbusta, T.collina and T.postomma, are described from Papua New Guinea. Males of the genus are described for the first time. A key to the workers of recognized species and a distribution map are provided. The group is analysed cladistically and the resulting species relationships are discussed, along with a comment on the use of polymorphic characters.     

黑头酸臭蚁微卫星标记的分离与开发(英文)

【目的】本研究旨在分离黑头酸臭蚁Tapinoma melanocephalum基因组微卫星标记,确定这些微卫星位点的多态性。【方法】使用454 GS-FLX焦磷酸测序技术开发来自中国华南陆地和岛屿的11个黑头酸臭蚁地理种群基因组微卫星位点。从随机设计的100对微卫星引物中筛选出10对引物,用于确定黑头酸臭蚁4个地理种群［东澳岛(DAD)、荷包岛(HBD)、梅州(MZ)和山咀(SJ)］10个微卫星位点的多态性,分析种群遗传多样性和种群分化。【结果】从11个黑头酸臭蚁地理种群基因组中成功开发和分离10对微卫星引物。在DAD, HBD, MZ和SJ 4个地理种群中,10个微卫星位点中7个有高多态性,这10个位点均显著偏离Hardy-Weinberg平衡;每个位点的等位基因数量(A)是3.50~9.00个,每个地理种群每个位点等位基因丰富度(A_R)在1.992~12.938之间。岛屿地理种群(DAD和HBD)的AR和预期杂合度(H_E)与大陆地理种群(MZ和SJ)的相比差异不显著。4个地理种群均显示高水平遗传分化(F_ST=0.15969);HBD和MZ种群与其他配对地理种群相比,遗传分化较高(F_ST=0.185),基因流较低,说明这两个种群基因流被限制。此外,遗传变异来自种群内个体之间。【结论】筛选新的微卫星位点能够为研究黑头酸臭蚁种群结构和繁殖结构提供有效工具,以深入了解其传播机制。     

日本弓背蚁肠道细菌群落的季节特征

[目的]在长期的进化过程中,蚂蚁和微生物之间建立了复杂的联系,尤其肠道微生物对蚂蚁的食性进化和物种分化产生了巨大的影响.弓背蚁属Camponotus蚂蚁消化道内普遍存在内共生菌Blochmannia及其他肠道细菌,这些细菌在寄主蚂蚁营养补充方面发挥了重要的作用,此外肠道微生物对食物类型的变化十分敏感,这些信息可能有助于调查寄主蚂蚁在不同季节的取食习性.本研究旨在揭示弓背蚁属蚂蚁肠道微生物是否存在季节特征.[方法]采用16S rRNA-RFLP方法分析比较了了2个日本弓背蚁蚁巢(巢1和2)的工蚁在4个月份时间点(2012年6月12日,8月15日和10月10日,2013年4月15日)的肠道茵群组成.[结果]在8个样品中共发现了17个属的细菌和1种未知细菌,弓背蚁属蚂蚁特有的内共生茵Blochmannia是优势细菌,出现在所有样品中,占67.1％～98.8％;假单胞菌属Pseudomonas和肠杆菌属Enterobacter在大多数的样本中都检测到,其他属的细菌则零星分布在个别样品中,只占较低的比例.两个蚁巢工蚁肠道茵群在4个月份没有呈现一致的变化趋势,都具有低的细菌多样性.在巢1中,4月和10月的肠道细菌多样性相对较高,在6月和8月较低;而在巢2中,8月的肠道细菌多样性明显高于4,6和10月.两个蚁巢6月和10月的肠道茵群组成相似,但是8月和4月差异较大.[结论]日本弓背蚁两个蚁巢的工蚁肠道菌群组成和多样性都随季节产生变化,但是没有呈现一致的变化趋势,没有表现出明显的季节特征.     

Recovery of ground ant (Hymenoptera: Formicidae) communities six years after a major environmental disaster

The recovery of ant communities at the Guadiamar River bank (southwest Spain) was studied across 5 yr, after an environmental disaster caused by the spill of toxic sludge over the river caused by a mine accident. Three affected and three control sites were sampled from 2000 to 2004 using pitfall traps. The last year of study, a more exhaustive sampling was conducted at the affected area (eight sampling sites). Additionally, four adjacent study sites not affected by the toxic spill were also studied. Ants showed clear responses to the restoration of the area. Mean ant species richness in spillage affected sites showed a significant increase over the 5 yr. Moreover, multivariate analysis showed distinct changes of ant community composition of the affected area over the years that were not observed in control sites. Six years after the disaster, one half of the species recorded in control sites were also present in the affected area, with only one species exclusive to this area, Cardiocondyla mauritanica Forel (tramp species). However, not only habitat specialist species but also some generalist and conspicuous species within the river basin are not present along the affected area, including species of the genera Camponotus, Messor, Cataglyphis, and Aphaenogaster. This study shows an incipient recovery of ant communities 6 yr after a major environmental disturbance, highlighting the absence of any invasive ant species in the restored area.     

A review of Bahamian ant (Hymenoptera: Formicidae) biogeography

Abstract. The results of recent surveys for ants on Staniel Cay, Exumas (and surrounding small cays) and the northeastern region of Andros are presented. These records are compiled with all previously published collection records of ants from the Bahamas into a single database. A list of all known Bahamian species is presented, in accord with current taxonomy. Distributions within the Bahamas are given, along with the status of each species with reference to its origin (endemic, native, or exotic). At present seventy-five named species of ants are known from the Bahamas, which shares 60% of its ant fauna with Florida and 71% with Cuba. More than one third of the species (37%) are exotics, which appear to exist primarily in areas characterized by human disturbance, and apparently have not invaded the native vegetation to a large degree. Both historical and ecological factors are likely to have played important roles in shaping present-day Bahamian ant species diversity and distribution. The number of species on all major Bahamian islands from which ants have been collected is presented as a function of island area. Most islands have not been very thoroughly surveyed. The species-area relationship for the more thoroughly surveyed islands is relatively flat (z= 0.06). Further collecting in this archipelago will probably lead to the discovery of additional species.     

Molecular phylogeny of the ant tribe Myrmicini (Hymenoptera: Formicidae)

The interrelationships within ant subfamilies remain elusive, despite the recent establishment of the phylogeny of the major ant lineages. The tribe Myrmicini belongs to the subfamily Myrmicinae, and groups morphologically unspecialized genera. Previous research has struggled with defining Myrmicini, leading to considerable taxonomic instability. Earlier molecular phylogenetic studies have suggested the nonmonophyly of Myrmicini, but were based on limited taxon sampling. We investigated the composition of Myrmicini with phylogenetic analyses of an enlarged set of taxa, using DNA sequences of eight gene fragments taken from 37 representatives of six of the seven genera (Eutetramorium, Huberia, Hylomyrma, Manica, Myrmica, and Pogonomyrmex), and eight outgroups. Our results demonstrate the invalidity of Myrmicini as currently defined. We recovered sister‐group relationships between the genera Myrmica and Manica, and between Pogonomyrmex and Hylomyrma. This study illustrates that to understand the phylogeny of over 6000 myrmicine species, comprehensive taxon sampling and DNA sequencing are an absolute requisite. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 160 , 482–495.     

Generic-level relationships within the ant subfamily Dolichoderinae (Hymenoptera: Formicidae)

A cladistic analysis was undertaken to determine relationships among extant genera of the ant subfamily Dolichoderinae. Twenty-one of the twenty-two currently recognized genera within the subfamily were examined using 104 morphological characters. A single fully resolved, most-parsimonious tree was found when a combination of ordered and unordered characters was used. When all characters were coded as unordered, seventy most-parsimonious trees were found. The following results were found with both character coding methods. Leptomyrmex was placed basal to the remainder of the subfamily and the monophyletic sets Dolichoderus + Liometopum + Axinidris + Tapinoma + Technomyrmex, Froggattella + Iridomyrmex + Ochetellus + Papyrius + Philidris + Turneria , and Bothriomyrmex + Dorymyrmex + Forelius + Loweriella were suggested. The genera Linepithema and Doleromyrma showed a small amount of instability in moving between neighbouring sister groups when the character coding method changed. The genera Anillidris and Anonychomyrma were difficult to place as they showed major differences in their positions between the two character coding methods.     

Long-term effects of fire on ant communities (Hymenoptera: Formicidae) in Pinus brutia forests of south-western Turkey

We studied how forest fire affects the structure of ant communities in the long term and how microhabitat variables that influence communities of ants in different succession stages change. For this purpose, we selected five sites burnt 3 to 26 years prior to the study and a control site unburnt for at least 50 years. Sampling of ants was conducted in four pit-fall traps in four transects in three replication plots at every successional site and in two plots at the control site. Microhabitat variables regarding the vegetation structure and litter layers were recorded and related to the abundances of ants. The results show that subshrubs, leaves, and needles were the most important microhabitat variables that affected the ant communities. In certain ant genera, significant changes depending upon successional gradient were determined. While the genera Aphaenogaster and Cataglyphis had non-linear relationships with successional gradient, negative linear relationships were found in Crematogaster and Prenolepis. Messor is the only genus caught in high numbers in the earliest successional stage. It showed a decrease with successional gradient. Significant changes in ant communities along the successional gradient were associated with the characteristics of vegetation and the litter layer.     

Population genetics of the black ant Formica lemani (Hymenoptera: Formicidae)

Colony kin structure and spatial population structure were studied in multiple populations of the ant Formica lemani , using allozymes and DNA microsatellites. Average genetic relatedness between nestmate workers varied little between populations ( r  = 0.51–0.76), indicating that the average colony kin structure was relatively simple. Worker genotypes could not be explained with a single breeding pair in all nests, however, and the distribution of relatedness estimates across nests was bimodal, suggesting that single- and multi-queen colonies co-occur. We studied spatial population structure in a successional boreal forest system, which is a mixture of different aged habitats. Newly clear-cut open habitat patches are quickly colonized by F. lemani , where it is able to persist for a limited number of generations. Newly-founded populations showed signs of a founder effect and spatial substructuring, whereas older populations were more homogenous. This suggests that new populations are founded by a limited number of colonizers arriving from more than one source. Genetic differentiation among local populations was minor, indicating strong migration between them. There were, however, indications of both isolation by distance and populations becoming more isolated as habitat patches grew older.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 247–258.     

Exocrine chemistry of the myrmicine ant Zacryptocerus pusillus (Hymenoptera: Formicidae)

Minor workers of the ant Zacryptocerus pusillus have unusual exocrine secretions in both their mandibular and Dufour glands. The mandibular glands contain a 3:1 mixture of 4-heptanone and 4-heptanol, a mixture found only in the related species Z. varians. The Dufour gland contains a mixture of 13 aldehydes from C9 to C18, not previously encountered in ant secretions. The venom glands gave variable results with only nonanal present consistently.     

The higher classification of the ant subfamily Leptanillinae (Hymenoptera: Formicidae)

Abstract. Until now the ant subfamily Leptanillinae has been closely linked with the army ant subfamilies Dorylinae and Ecitoninae, but on relatively tenuous evidence. The current phylogenetic study strongly indicates that this view is incorrect and that the leptanillines really constitute the sister-group of subfamily Ponerinae, and are at a consider- ably greater taxonomic distance from the Army Ant subfamilies. Three tribes are now recognized within the Leptanillinae (Leptanillini; Anomalornyrmini, new tribe; and Apomyrmini, transferred here from Ponerinae: Arnblyoponini), containing a total of eight genera with fewer than fifty species in all. The subfamily and its component tribes are diagnosed and discussed here, and a key to genera provided. New taxa described include Anomalomyrma Taylor gen.n., type-species A. taylori Bolton sp.n. and Protanilla Taylor gen.n., type-species P. rafflesi Taylor sp.n.     

The visual perception of the ant Myrmica ruginodis (Hymenoptera: Formicidae)

Myrmica ruginodis workers are able to distinguish black or white circles from black or white squares, black or white ellipses from black or white rectangles as well as hollow circles or ellipses from hollow squares or rectangles. They can also distinguish differently oriented elements as well as objects containing a various number of elements. These workers are also able to perceive and discriminate transparent cues on a black background and even small luminous spots on a black ceiling. Such visual abilities are in agreement with the species?? eye morphology and system of navigation: the eyes are rather large with a well-developed posterio-dorsal part, and the foragers rely exclusively on cues located above them, neglecting odorous elements as long as visual perception is possible. Probably, they might use cues located in the canopy and the sky to travel in certain circumstances.