Myrmica ants host highly diverse parasitic communities: from social parasites to microbes

Myrmica ants have been model species for studies in a variety of disciplines, including insect physiology, chemical communication, ant social dynamics, ant population, community ecology, and ant interactions with other organisms. Species belonging to the genus Myrmica can be found in virtually every habitat within the temperate regions of the northern hemisphere and their biology and systematics have been thoroughly studied. These ants serve as hosts to highly diverse parasitic organisms from socially parasitic butterfly caterpillars to microbes, and many Myrmica species even evolved into parasitizing species of their own genus. These parasites have various impacts both on the individuals and on the social structure of their hosts, ranging from morphological malformations to reduction in colony fitness. A comprehensive review of the parasitic organisms supported by Myrmica and the effects of these organisms on individuals and on whole ant colonies has not yet been compiled. Here, we provide a review of the interactions of these organisms with Myrmica ants by discussing host and parasite functional, behavioral or physiological adaptations. In addition, for all “symbiont groups” of Myrmica ants described in this paper, we examine the present limitations of the knowledge at present of their impact on individuals and host colony fitness. In conclusion, we argue that Myrmica ants serve as remarkable resource for the evolution of a wide variety of associated organisms.     

Bottom-up effects of host-plant species diversity and top-down effects of ants interactively increase plant performance

While plant diversity is well known to increase primary productivity, whether these bottom-up effects are enhanced by reciprocal top-down effects from the third trophic level is unknown. We studied whether pine tree species diversity, aphid-tending ants and their interaction determined plant performance and arthropod community structure. Plant diversity had a positive effect on aphids, but only in the presence of mutualistic ants, leading to a threefold greater number of both groups in the tri-specific cultures than in monocultures. Plant diversity increased ant abundance not only by increasing aphid number, but also by increasing ant recruitment per aphid. The positive effect of diversity on ants in turn cascaded down to increase plant performance; diversity increased plant growth (but not biomass), and this effect was stronger in the presence of ants. Consequently, bottom-up effects of diversity within the same genus and guild of plants, and top-down effects from the third trophic level (predatory ants), interactively increased plant performance.     

化学防治对绿化带中红火蚁及本地蚂蚁的影响

研究了饵剂、粉剂和灌巢3种不同施药方法对红火蚁的防治效果及对绿化带本地蚂蚁的影响.结果表明:从活动蚁巢和工蚁减退率两项指标来看,粉剂防治绿化带中红火蚁效果快速稳定,可以推广使用;饵剂防治作用较缓慢,处理35d后达到最好的防治效果;而灌巢虽然能在短期内有效地减少活动蚁巢数量,但对工蚁的防效较差,总体上不如粉剂和饵剂.此外,饵剂和粉剂都能显著降低绿化带本地蚂蚁的种类和数量,灌巢则对本地蚂蚁的影响较小.通过分析施药前后各处理区的蚂蚁类群多样性指数、均匀度指数和优势度指数的变化,可以看出各处理区的蚂蚁类群多样性指数,均匀度指数和优势度指数与CK相比,都呈下降趋势,说明化学防治能有效压制红火蚁的数量,但同时也严重影响着本地蚂蚁.     

Ant community structure during forest succession in a subtropical forest in South-East China

Understanding how communities respond to environmental gradients is critical to predict responses of species to changing habitat conditions such as in regenerating secondary habitats after human land use. In this study, ground-living ants were sampled with pitfall traps in 27 plots in a heterogeneous and diverse subtropical forest to test if and how a broad set of environmental variables including elevation, successional age, and tree species richness influence ant diversity and community composition. In total, 13,441 ant individuals belonging to 71 species were found. Ant abundance was unrelated to all environmental variables. Rarefied ant species richness was negatively related to elevation, and Shannon diversity decreased with shrub cover. There was considerable variation in ant species amongst plots, associated with elevation, successional age, and variables related to succession such as shrub cover. It is shown that younger secondary forests may support a species-rich and diverse community of ants in subtropical forests even though the species composition between younger and older forests is markedly different. These findings confirm the conservation value of secondary subtropical forests, which is critical because subtropical forests have been heavily exploited by human activities globally. However, the findings also confirm that old-growth forest should have priority in conservation as it supports a distinct ant community. Our study identifies a set of ant species which are associated with successional age and may thus potentially assist local conservation planning.     

Booms,busts and population collapses in invasive ants

The abundance of many invasive species can vary substantially over time, with dramatic population declines and local extinctions frequently observed in a wide range of taxa. We highlight population crashes of invasive ants, which are some of the most widespread and damaging invasive animals. Population collapse or substantial declines have been observed in nearly all of the major invasive ant species including the yellow crazy ant (Anoplolepis gracilipes), Argentine ants (Linepithema humile), big-headed or coastal brown ant (Pheidole megacephala), the tropical fire ant (Solenopsis geminata), red imported fire ants (Solenopsis invicta), and the little fire ant or electric ant (Wasmannia auropunctata). These declines frequently attract little attention, especially compared with their initial invasion phase. Suggested mechanisms for population collapse include pathogens or parasites, changes in the food availability, or even long-term effects of the reproductive biology of invasive ants. A critical component of the collapses may be a reduction in the densities of the invasive ant species, which are often competitively weak in low abundance. We propose that mechanisms causing a reduction in invasive ant abundance may initiate a local extinction vortex. Declines in abundance likely reduce the invasive ant’s competitive ability, resource acquisition and defense capability. These reductions could further reduce the abundance of an invasive ant species, and so on. Management of invasive ants through the use of pesticides is expensive, potentially ecologically harmful, and can be ineffective. We argue that pesticide use may even have the potential to forestall natural population declines and collapses. We propose that in order to better manage these invasive ants, we need to understand and capitalize on features of their population dynamics that promote population collapse.     

Fire ant-detecting canines: a complementary method in detecting red imported fire ants

In this investigation, detection dogs are trained and used in identifying red imported fire ants, Solenopsis invicta Buren, and their nests. The methodology could assist in reducing the frequency and scope of chemical treatments for red imported fire ant management and thus reduce labor costs and chemical use as well as improve control and quarantine efficiency. Three dogs previously trained for customs quarantine were retrained to detect the scents of red imported fire ants. After passing tests involving different numbers of live red imported fire ants and three other ant species--Crematogaster rogenhoferi Mayr, Paratrechina longicornis Latreille, and Pheidole megacephala F.--placed in containers, ajoint field survey for red imported fire ant nests by detection dogs and bait traps was conducted to demonstrate their use as a supplement to conventional detection methods. The most significant findings in this report are (1) with 10 or more red imported fire ants in scent containers, the dogs had >98% chance in tracing the red imported fire ant. Upon the introduction of other ant species, the dogs still achieved on average, a 93% correct red imported fire ant indication rate. Moreover, the dogs demonstrated great competence in pinpointing emerging and smaller red imported fire ant nests in red imported fire ant-infested areas that had been previously confirmed by bait trap stations. (2) Along with the bait trap method, we also discovered that approximately 90% of red imported fire ants foraged within a distance of 14 m away from their nests. The results prove detection dogs to be most effective for red imported fire ant control in areas that have been previously treated with pesticides and therefore containing a low density of remaining red imported fire ant nests. Furthermore, as a complement to other red imported fire ant monitoring methods, this strategy will significantly increase the efficacy of red imported fire ant control in cases of individual mount treatment.     

Do lianas shape ant communities in an early successional tropical forest?

Almost half of lowland tropical forests are at various stages of regeneration following deforestation or fragmentation. Changes in tree communities along successional gradients have predictable bottom‐up effects on consumers. Liana (woody vine) assemblages also change with succession, but their effects on animal succession remain unexplored. Here we used a large‐scale liana removal experiment across a forest successional chronosequence (7–31 years) to determine the importance of lianas to ant community structure. We conducted 1,088 surveys of ants foraging on and living in trees using tree trunk baiting and hand‐collecting techniques at 34 paired forest plots, half of which had all lianas removed. Ant species composition, β‐diversity, and species richness were not affected by liana removal; however, ant species co‐occurrence (the coexistence of two or more species in a single tree) was more frequent in control plots, where lianas were present, versus removal plots. Forest stand age had a larger effect on ant community structure than the presence of lianas. Mean ant species richness in a forest plot increased by ca. 10% with increasing forest age across the 31‐year chronosequence. Ant surveys from forest >20 years old included more canopy specialists and fewer ground‐nesting ant species versus those from forests <20 years old. Consequently, lianas had a minimal effect on arboreal ant communities in this early successional forest, where rapidly changing tree community structure was more important to ant species richness and composition.     

Nutrient use by tropical ant communities varies among three extensive elevational gradients: A cross-continental comparison

Aim

Many studies demonstrate that climate limits invertebrates along tropical elevational gradients, but we have only a rudimentary understanding of the role of nutrient limitation and climatic seasonality. Here we examined the relationships between ant community structure, nutrient use and season along three undisturbed elevational gradients, each from a different continent.

Location

Ecuador (South America), Papua New Guinea (PNG: Oceania), Tanzania (Africa).

Time period

2011–2014.

Major taxa studied

Ants.

Methods

Along each of the three gradients, we placed six distinct nutrient types (amino acid, sucrose, sucrose + amino acid, lipid, NaCl, H₂O). In total, we distributed 2370 baits at 38 sites from 203 m to 3972 m. We used generalized linear models to test for the effects of elevation and season on ant species richness and activity and relative nutrient use. We also tested if changes in ant trophic guilds corresponded to changes in the use of particular nutrients.

Results

Both species richness and activity decreased with elevation along each gradient. However, there were significant interaction effects among elevation, region and season, as ant activity in the dry season was higher in Ecuador and Tanzania but lower in PNG. Relative nutrient use varied among regions: ant preference for some nutrients changed with increasing elevation in Ecuador (decrease in lipid use) and Tanzania (decrease in amino acid and H₂O use), while season affected nutrient use in PNG. There were common trends in trophic guilds along the three elevational gradients (e.g. proportional increase of predators), but these did not explain most of the nutrient use patterns.

Main conclusion

While the structure of ant communities changed similarly with elevation, both the seasonal and elevational effects on nutrient use by ants differed between continents. We argue that regional differences in climate and nutrient availability rather than ant functional composition shape nutrient use by ants.     

Environmental heterogeneity and interspecific interactions influence nest occupancy by key seed-dispersing ants

The complex interplay between species along environmental gradients ultimately shapes their distributions and additional community interactions. Ant-mediated seed dispersal fails in the wettest habitat of deciduous forest in eastern North America, and we examine whether this pattern corresponds with colony distributions for seed-dispersing ants and associated heterogeneity in abiotic and biotic variables. Specifically, we used spatial variation in soil moisture, temperature and diffuse light along natural habitat gradients and experimentally manipulated soil moisture gradients to examine ant habitat selection. We also examined niche segregation between effective (Aphaenogaster spp.) and ineffective (Lasius alienus Foerster) seed-dispersing ants across these environmental gradients. Whereas most research links ant foraging and nesting with temperature gradients, we find niche segregation between Aphaenogaster spp. and L. alienus by soil moisture along naturally occurring gradients and in experimentally irrigated upland habitat. The failure of Aphaenogaster spp. to occupy the wettest habitats, where L. alienus is present, is consistent with observed seed dispersal failure in these habitats. These results indicate that environmental heterogeneity drives niche segregation between effective (Aphaenogaster spp.) and ineffective (L. alienus) seed dispersers so each occupies distinct habitat. Most forest understory plants rely on ants for seed dispersal. Our research implies that climate-mediated interactions between effective and ineffective seed dispersing ant species may structure the microhabitat distributions for woodland herbs.     

Using ants to manage sustainable grazing: Dynamics of ant faunas along sheep grazing gradients conform to four global patterns

Ants are considered an important faunal group for the functioning of arid rangelands, they have a long history of use for environmental monitoring, and exhibit four global patterns in grazing lands: (i) soil and vegetation type are primary determinants of ant community composition, and have a far greater effect on ant community composition than grazing; (ii) grazing induces species compositional change, but does not necessarily affect species richness or abundance; (iii) a species response to grazing is not necessarily consistent across habitats; and (iv) approximately one‐quarter to one‐half of species that are common enough for statistical analysis have significant responses to grazing. Here we report the patterns of arid zone ant faunas as they exist after several decades of sheep grazing in southern Australia, and examine the extent to which they conform to the four global patterns. We measured ant faunas along grazing gradients (varying distance to water) in seven paddocks containing two soil and two vegetation types on five pastoral properties. Total site abundance and richness of ants did not differ significantly with distance from water, but the abundance of 10 (34%) of the 29 most common species did differ; three were increasers, three were decreasers, and four had mixed responses dependent on soil/vegetation type. Rare species showed no trend with grazing intensity. The ant fauna of the more structurally complex vegetation types appeared to be the most vulnerable to grazing effects. Multivariate analysis showed soil type was the primary factor influencing ant faunal composition, followed by vegetation structure; however, grazing treatment effects were present. This study fully supports the recently identified global patterns of ant responses to grazing. It also shows that sampling regional ant faunas using widely dispersed traps can detect ant faunal patterns comparable to studies that use smaller‐scale grids of traps.     

A canopy dominant ant affects twig‐nesting ant assembly in coffee agroecosystems

One commonly studied driver of community assembly is the effect of dominant species on subordinate species. Dominant species may impact community assembly during competitive sorting, or recruitment. For ants, important and abundant species in the tropics, several factors may drive community assembly including competition, dispersal, priority effects, and environmental conditions. Although competition is a hallmark of ant ecology, few have examined the influence of patchily distributed dominant ants on other ant species and diversity, especially at the recruitment stage. Here, I consider the impacts of a canopy dominant ant species, Azteca instabilis, and changes in vegetation on twig‐nesting ant colony founding and ant community assembly in a coffee agroecosystem. I added artificial nests to coffee plants in areas with and without A. instabilis four times over a year, and then examined the occupation rate and identity of species colonizing nests. I also examined vegetation characteristics of sites where nests were added. The presence of A. instabilis on coffee plants drastically lowered colonization rates, but nest occupation increased with tree density, and with decreasing proportion of Inga spp. trees in the canopy. The presence of A. instabilis limited the number of nests occupied by six of the ten most common species; most rare species, however, were not affected by A. instabilis presence. Richness of colonizing ants in areas with A. instabilis was lower, but these effects did not significantly affect richness across broader scales. Despite large effects on individual species, species composition did not differ greatly in areas with and without A. instabilis, but some vegetation characteristics (basal area and tree richness) were predictive of ant composition. These results suggest that A. instabilis strongly affects founding events especially for common twig‐nesting species and that both vegetation and influences from this dominant species affect community assembly of twig‐nesting ants at the local scale.     

Native harvester ants threatened with widespread displacement exert localized effects on serpentine grassland plant community composition

Seed-harvesting ants can influence the abundance and distribution of plant species through both the selective harvesting of seeds and the construction of nutrient-rich nest mounds, but the relative contributions of these two mechanisms have not been addressed by previous studies. Furthermore, the impact of ant seed harvesting in California serpentine grasslands remains unresolved because of divergent results from several previous experiments. This study investigates the influence of harvester ants on serpentine grassland plant species composition by examining two potential signatures of seed harvesting ants on plant community composition: species composition on versus off ant nest mounds, and species abundance as a function of distance from nest mounds. Of the 28 plant species identified in this study, 22 exhibited spatial patterns consistent with effects of seed harvesting, nest construction, or both. Although most species showed significant gradients in abundance with distance from a nest, there were no clear relationships between plant species distributions and previously reported harvester ant seed foraging patterns. Harvester ant nest mounds supported plant communities that were distinct from the surrounding serpentine grassland, with notably higher densities of legumes and invasive annual grasses. Comparison of our results with those of previous studies indicates that the patterns we observed are generally consistent over time, but affect more species and a larger fraction of the grassland than previously reported. Unaffected areas of the grassland seem likely to serve as important refuges for some plant species.     

Effects of selective logging on the arboreal ants of a Bornean rainforest

We examined the effect of selective logging and corresponding forest canopy loss on arboreal ant diversity in a tropical rainforest. Arboreal ants were collected from an unlogged forest plot and from forest plots selectively logged 14 years and 24 years earlier in Danum Valley, Sabah, Malaysia, using a canopy fogging method. Selective logging was associated with a significant decrease in canopy cover and an increase in understory vegetation density relative to unlogged forest. Our study showed that selective logging in primary forest might not dramatically decrease total species number and overall abundance of arboreal ants; however, it may influence the species composition and dominance structure of the ant community, accompanied by an increase in abundance of shrub‐layer species and trophobiotic species. In view of the results of this study, management techniques that minimize logging impact on understory vegetation structure are likely to help maintain the conservation value of logged forests for arboreal ants. Our results also suggest that accurate assessment of the impacts on biodiversity should not be based only on measurement of species number and overall abundance, but also on analysis of species composition and community structure.     

Interference competition by Argentine ants displaces native ants: implications for biotic resistance to invasion

The Argentine ant Linepithema humile (Dolichoderinae) is one of the most widespread invasive ant species in the world. Throughout its introduced range, it is associated with the loss or reduced abundance of native ant species. The mechanisms by which these native species are displaced have received limited attention, particularly in Australia. The role of interference competition in the displacement of native ant species by L. humile was examined in coastal vegetation in central Victoria (southeastern Australia). Foragers from laboratory colonies placed in the field consistently and rapidly displaced the tyrant ant Iridomyrmex bicknelli, the big-headed ant Pheidole sp. 2, and the pony ant Rhytidoponera victoriae from baits. Numerical and behavioural dominance enabled Argentine ants to displace these ants in just 20 min; the abundance of native species at baits declined 3.5–24 fold in direct relation to the rapid increase in L. humile. Most precipitous was the decline of I. bicknelli, even though species in this typically dominant genus have been hypothesized to limit invasion of L. humile in Australia. Interspecific aggression contributed strongly to the competitive success of Argentine ants at baits. Fighting occurred in 50–75% of all observed interactions between Argentine and native ants. This study indicates that Argentine ants recruit rapidly, numerically dominate, and aggressively displace from baits a range of Australian native ant species from different subfamilies and functional groups. Such direct displacement is likely to reduce native biodiversity and indirectly alter food web structure and ecosystem processes within invaded areas. Biotic resistance to Argentine ant invasion from native ants in this coastal community in southeastern Australia is not supported in this study.     

A test of species–energy theory: patch occupancy and colony size in tropical rainforest litter‐nesting ants

Species–energy theory can account for spatial variation in the abundance and community composition of animals, though the mechanisms of species–energy theory are under contention. We evaluated three competing mechanisms at the local spatial scale by conducting an in vivo light manipulation over supplemental ant nests placed in the leaf litter of a Costa Rican tropical rainforest. We found that the light environment did not alter the 10% rate of occupation of the supplemental nests, but light did alter the size of colonies and the genus‐level composition of the community. Light levels in the foraging range were positively associated with colony sizes of all ants, whereas light levels directly on the nest site were predictive of the occurrence of ant genera. Colonies of specialized predators, dacetine ants, were larger in more shaded foraging environments, and the functional group of generalized myrmicines exhibited an opposite pattern, with smaller‐sized colonies in response to shading. Responses of twig‐dwelling ants to the light environment were most consistent with the metabolic cost hypothesis as a mechanism of species–energy theory. We found mixed support for the thermal energy availability hypothesis, and scant support for the chemical energy hypothesis, as the litter depth, a measure of prey density, was not predictive of ant responses. In summary, at the local scale, we found patterns in colony size and life history are governed by light‐dependent mechanisms.     

Ant community succession within eucalypt plantations on used pasture and implications for taxonomic sufficiency in biomonitoring

Abstract Ground‐active ants were sampled from three habitats: (i) a 10‐year‐old Eucalyptus punctata plantation, (ii) native woodland regrowth, and (iii) the surrounding pasture, at a study site in the Hunter Valley, New South Wales, Australia. A previous study, undertaken 6 years earlier at the same study sites, revealed no difference in species richness or composition between the eucalypt plantation and pasture. The aims of the present study were: (i) to investigate the successional change in ant community structure within the plantations; and (ii) to evaluate what levels of taxonomic identification were sufficient to indicate a change had taken place. Univariate statistics (anova ) were used to compare estimates of assemblage richness between habitats using data classified at five levels of taxonomic resolution: species, morphospecies, easily recognisable taxonomic units, genus and functional group. Multivariate statistics (anosim and non‐metric multidimensional scaling) were used to compare ant assemblages between habitats and between sampling events at a range of taxonomic resolutions from species to functional group. This study found: (i) a significant temporal change in community composition was evident using species, genus and functional group level data, but no change was detected in the pasture or woodland; (ii) mean ant species, morphospecies and easily recognisable taxonomic units richness were significantly greater within the plantations than the pasture; (iii) compositional differences between the plantation and pasture assemblages were evident at all levels of taxonomic resolution; (iv) mean ant species and genus richness were significantly higher in the woodland than in the plantation, and these two habitats were compositionally distinct at all levels of taxonomic resolution. This is the first case study to have documented a successional response from ants to the revegetation of agricultural land with eucalypt plantations. Reasons for the temporal and interhabitat differences in community structure are discussed, as well as the implications for taxonomic sufficiency in monitoring ant community successions.     

Patterns of abundance of fire ants and native ants in a native ecosystem

Abstract 1. This correlational study examines the relationship between the red imported fire ant (Solenopsis invicta) and native ants in a longleaf pine savanna. Fire ants are frequently associated with a decline in native ants throughout the invaded range, but fire ant invasion is often coupled with habitat disturbance. Invasion of fire ants into the longleaf pine savanna provides an opportunity to examine the structure of the ant community in the absence of habitat disturbance. 2. Pitfall trapping was conducted within the longleaf pine savanna as well as across a naturally occurring soil moisture gradient, in plots that had been artificially watered. 3. Species richness did not vary as a function of fire ant density. There was an inverse relationship between native ant density and fire ant density, but this abundance pattern does not necessarily imply a causal link between fire ant invasion and native ant decline. For individual species, fire ant densities were negatively correlated with the densities of only two native ant species, including Solenopsis carolinensis, a native species that potentially limits the invasion of fire ants. Additionally, fire ants and native ants respond differently to soil moisture, with native ants favouring drier conditions than fire ants. 4. The possible exclusion of fire ants by some native ants, as well as differences in habitat preferences, provide alternative explanations for the frequently observed negative correlation between fire ants and native ants.     

Exploring arboreal ant community composition and co-occurrence patterns in plantations of oil palm Elaeis guineensis in Borneo and Peninsular Malaysia

The oil palm, Elaeis guineensis , is a native of West Africa and is now extensively grown in south-east Asia. In 2005, the crop covered four million ha of Malaysia. We examined the arboreal ant fauna in two oil palm plantations that had been farmed with integrated pest management practices for at least 10 yr. Having cut and examined palm fronds from 595 and 503 palms in Borneo and Peninsular Malaysia respectively, we studied diversity in ant assemblages, analysed composition of ant mosaics by stepwise use of null-models, and explored the influence of exotic vs native species on community structure. Altogether we sampled 52 species of canopy ants, of which 23 species were shared between Borneo and Peninsular Malaysia. Seventeen species in Borneo and 24 species in Peninsular Malaysia accounted for 95% of all species occurrences (SOCs). Fortysix percent of all SOCs belonged to 12 tramp ant species with pan-tropical distributions. Forty percent of all SOCs were exotic ants. Six dominant species were found in Borneo, five in the Peninsula. The three most abundant species, Anoplolepis gracilipes , Oecophylla smaragdina and Technomyrmex albipes were dominant in both sites. Three dominants were invasive species that were found on more palms than the native group. Dominant tramp species coexisted with non-dominants more often and tolerated more species of non-dominant ants than native dominants. Null model analyses indicated that species were arranged in mosaics at both the Peninsular Malaysia and Borneo sites. Dominant species showed much less co-occurrence than expected by chance, pointing towards species segregation (even in presence of introduced, invasive species). Similar results were obtained for all species. Non-dominant ants were either positively associated with their dominants, or co-occurred randomly in the presence of dominant species. In contrast, ant assemblages on palms without dominants showed species segregation.     

The ant fauna of Castelporziano Presidential Reserve (Rome,Italy) as a model for the analysis of ant community structure in relation to environmental variation in Mediterranean ecosystems

Ants are often used as ecological indicators in environmental monitoring programs, but rarely in Europe, probably because of a lack of baseline knowledge on the relationship between ant community structure and environmental variation. We present this baseline knowledge for Italian ecosystems that are typical of the Mediterranean climate, in order to assess the value of ants as ecological indicators in this biogeographic zone. Sampling areas were selected inside the Castelporziano Natural Reserve (Rome, Italy). The elevated variety of habitats and diverse ecological conditions, as well as the different levels of human impact in the Reserve, make this area a suitable location to develop and test biological indicators of environmental quality. The ant community structure was compared among several Mediterranean ecosystems using pitfall trapping, multidimensional scaling, the indicator species analysis and the Functional Groups Approach. Key factors for differences in ant community structure seem to be the presence/absence of water, the level of light and microhabitat diversity. Our results suggest that Castelporziano is an informative area in order to develop a study model for the Italian ant fauna and the Functional Group Approach is a promising procedure to associate differences in ant community structures with differences in habitat stress and disturbance.     

切叶蚁亚科蚂蚁的防御性生物碱

蚂蚁(蚁科)有显著的群居特性,个体间分工明确,并具有复杂的合作策略,以保护巢穴不受捕食者、病原微生物、蚂蚁竞争者的侵害,以及捕食猎物等.切叶蚁亚科是蚁科的最大类群,共有147个现生属,主要通过喷洒富含生物碱的毒液分泌物进行防御和捕猎.本文综述了该亚科防御性生物碱的组分及属种分布特征,其结构类型包括哌啶、吡啶、吡咯、吲哚...