| forager size of the leaf-cutting ant atta sexdens (hymenoptera: formicidae) in a mature eucalyptus forest in brazil. | we determined the size characteristics of foragers of the leaf-cutting ant atta sexdens in a mature eucalyptus forest in campos dos goytacazes, rio de janeiro state, brazil, at daytime (7:30 to 10:00 hr) and nighttime (19:00 to 23:00 hr). there were no significant differences between daytime and nighttime ant mass (ma), but leaf fragment mass (ml) and burden (b = [ma + ml]/ma), which indicates relative load capacity, were significantly greater at daytime. there was a positive linear relationship ... | 2000 | 11487943 |
| isolation, growth characteristics, and long-term storage of fungi cultivated by attine ants. | seven pure-culture strains of fungi cultivated by attine ants (ant-garden fungi) were isolated from locally maintained leaf-cutting ant colonies. an ant-garden fungus strain obtained from an atta cephalotes colony, when offered to ants of the colony from which the fungus was isolated, was accepted as their own. young fungus cultures were harvested and incorporated into the fungus garden, and cultures of intermediate age were used to begin a new fungus garden; old cultures were simply harvested. ... | 1989 | 16347927 |
| small genome of the fungus escovopsis weberi, a specialized disease agent of ant agriculture. | many microorganisms with specialized lifestyles have reduced genomes. this is best understood in beneficial bacterial symbioses, where partner fidelity facilitates loss of genes necessary for living independently. specialized microbial pathogens may also exhibit gene loss relative to generalists. here, we demonstrate that escovopsis weberi, a fungal parasite of the crops of fungus-growing ants, has a reduced genome in terms of both size and gene content relative to closely related but less speci ... | 2016 | 26976598 |
| discovery of defense- and neuropeptides in social ants by genome-mining. | natural peptides of great number and diversity occur in all organisms, but analyzing their peptidome is often difficult. with natural product drug discovery in mind, we devised a genome-mining approach to identify defense- and neuropeptides in the genomes of social ants from atta cephalotes (leaf-cutter ant), camponotus floridanus (carpenter ant) and harpegnathos saltator (basal genus). numerous peptide-encoding genes of defense peptides, in particular defensins, and neuropeptides or regulatory ... | 2012 | 22448224 |
| genetic caste polymorphism and the evolution of polyandry in atta leaf-cutting ants. | multiple mating by females with different males (polyandry) is difficult to explain in many taxa because it carries significant costs to females, yet benefits are often hard to identify. polyandry is a derived trait in social insects, the evolutionary origins of which remain unclear. one of several leading hypotheses for its evolution is that it improves division of labour by increasing intra-colonial genetic diversity. division of labour is a key player in the ecological success of social insec ... | 2011 | 21656003 |
| rapid shifts in atta cephalotes fungus-garden enzyme activity after a change in fungal substrate (attini, formicidae). | fungus gardens of the basidiomycete leucocoprinus gongylophorus sustain large colonies of leaf-cutting ants by degrading the plant material collected by the ants. recent studies have shown that enzyme activity in these gardens is primarily targeted toward starch, proteins and the pectin matrix associated with cell walls, rather than toward structural cell wall components such as cellulose and hemicelluloses. substrate constituents are also known to be sequentially degraded in different sections ... | 2011 | 21475686 |
| coffee farm diversity and landscape features influence density of colonies of atta cephalotes (hymenoptera: formicidae). | the density of colonies of leaf-cutting ants, atta cephalotes l. (hymenoptera: formicidae), was measured and compared among coffee (coffea arabica l.) plantations in five management categories: monoculture conventional, diversified conventional, diversified organic, highly diversified conventional, and highly diversified organic. twenty-four small farms (<4 ha) in turrialba, costa rica, were included in this study. within-farm and off-farm (landscape) variables were measured and tested for their ... | 2011 | 21404854 |
| random amplified polymorphic dna markers reveal genetic variation in the symbiotic fungus of leaf-cutting ants. | rapd markers were used to examine the degree of genetic variation within the putatively asexual basidiomycete fungus (lepiotaceae: provisionally named leucoagaricus gongylophorus) associated with the leaf-cutting ant species atta cephalotes. we analyzed fungal isolates from ant nests in two geographically distant sites, two isolates from panama and five isolates from trinidad. ten decamer primers were used to amplify total dna from these seven fungal isolates, and rapd banding patterns were comp ... | 2003 | 21156584 |
| edge-induced narrowing of dietary diversity in leaf-cutting ants. | much of the ecological alteration faced by human-modified neotropical forests can be assigned to edge effects, including the proliferation of some voracious herbivores such as leaf-cutting ants. however, the underlying mechanisms/impacts of tropical forest edge on herbivores performance and their foraging behaviour (e.g. dietary diversity) have rarely been investigated. the goal of this study was, therefore, to determine whether and how the annual diet (i.e. species richness, diversity and the r ... | 2010 | 21034522 |
| traffic dynamics of the leaf-cutting ant, atta cephalotes. | colonies of atta cephalotes (myrmicinae: formicidae) construct cleared paths between their nest and the vegetation sources at which they harvest leaf tissue. here, we employ ideas from traffic engineering to study streams of laden and unladen ants on these paths. the relationship between average traffic speed and the concentration of workers on the road surface follows a relationship similar to what is expected by analogy to fluid dynamics. although the traffic is composed of eusocial organisms ... | 2002 | 18707380 |
| nuclear mitochondrial-like sequences in ants: evidence from atta cephalotes (formicidae: attini). | nuclear mitochondrial-like sequences (numts) are copies of mitochondrial dna that have migrated to the genomic dna. we present the first characterization of numts in ants, these numts being homologues to a mitochondrial dna fragment containing loci the 3' portion of the cytochrome oxidase i gene, an intergenic spacer, the trna leucine gene and the 5' portion of the cytochrome oxidase ii gene. all 67 specimens of atta cephalotes (hymenoptera: formicidae: attini) investigated had these homologues, ... | 2007 | 18093006 |
| fungus-growing ants. | fungus-growing ants (attini) are in reality unique fungus-culturing insects.there are several hundred species in some dozen genera, of which acromyrmex and atta are the conspicuous leaf-cutters. the center of their activities is the fungus garden, which is also the site of the queen and brood. the garden, in most species, is made from fresh green leaves or other vegetal material. the ants forage for this, forming distinct trails to the vegetation that is being harvested. the cut leaves or other ... | 1966 | 17757227 |
| synergistic effects of three piper amides on generalist and specialist herbivores. | the tropical rainforest shrub piper cenocladum, which is normally defended against herbivores by a mutualistic ant, contains three amides that have various defensive functions. while the ants are effective primarily against specialist herbivores, we hypothesized that these secondary compounds would be effective against a wider range of insects, thus providing a broad array of defenses against herbivores. we also tested whether a mixture of amides would be more effective against herbivores than i ... | 2003 | 14682530 |
| in vitro evaluation of trichoderma and gliocladium antagonism against the symbiotic fungus of the leaf-cutting ant atta cephalotes. | the antagonistic activity of trichoderma and gliocladium isolates against attamyces sp., a symbiotic fungus of the leaf-cutting ant atta cephalotes, was investigated. a. cephalotes cultures this fungus as the primary food source. most of the trichodema and gliocladium isolates tested in vitro (82.6%) inhibited the attamyces sp. mycelial growth. which was probably due to their colonization ability and competition for nutrients, both of them known mechanisms of some species of these genera. t. lig ... | 2001 | 11407491 |
| foraging behaviour of atta cephalotes (leaf-cutting ants): an examination of two predictions for load selection. | two mechanisms have been proposed to explain how colony-level foraging performance of leaf-cutting ants can be maximized when workers harvest leaf fragments of a size that does not maximize their individual performance. each mechanism predicts that ants will adjust the size of leaf fragments between starting a foraging bout and establishing full traffic between the nest and foraging site, but the two models predict shifts in opposite directions. i examined fragment sizes at the start of daily fo ... | 2000 | 11124876 |
| leaf caching in atta leafcutting ants: discrete cache formation through positive feedback. | we examined the occurrence, mechanism and costs and benefits of leaf caching in laboratory colonies of two species of leafcutting ants, atta cephalotes and a. colombica. if foragers returning to the nest are unable to enter because of a temporary bottleneck caused by leaves building up they may deposit their leaf pieces outside the nest entrance, forming a leaf cache. similar leaf caches occur in the field at foraging trail junctions, obstacles on the trail and within nest entrance tunnels. fora ... | 2000 | 10715181 |
| evidence of a novel immune responsive protein in the hymenoptera. | honeybee populations are severely threatened by parasites and diseases. recent outbreaks of colony collapse disorder (ccd) has caused loss of more than 35% of bee colonies in the usa, and this is thought to at least in part be due to parasites and/or disease. interestingly, the honeybee possesses of a limited set of immune genes compared to other insects. non-canonical immune genes of honeybee are of interest because they may provide greater insights into the peculiar nature of the immune system ... | 2011 | 22001069 |
| biological responses of atta texana to its alarm pheromone and the enantiomer of the pheromone. | s-(+)-4-methyl-3-heptanone is the principal alarm pheromone of atta texana. the dextrorotatory form of the ketone has also been identified from atta cephalotes. both enantiomers have been synthesized in high optical purity; atta texana is more responsive to the (+) enantiomer than to the (-) form. these results implicate a chiral receptor system. | 1974 | 17790626 |
| [antiparasite defense of minima workers of the leaf-cutting ant (atta cephalotes)]. | | 1967 | 5598387 |
| duplication and concerted evolution in a master sex determiner under balancing selection. | the transformer (tra) gene is a key regulator in the signalling hierarchy controlling all aspects of somatic sexual differentiation in drosophila and other insects. here, we show that six of the seven sequenced ants have two copies of tra. surprisingly, the two paralogues are always more similar within species than among species. comparative sequence analyses indicate that this pattern is owing to the ongoing concerted evolution after an ancestral duplication rather than independent duplications ... | 2013 | 23466984 |
| attine fungus gardens contain yeasts. | yeasts were detected in the fungus gardens of atta cephalotes and acromyrmex octospinosus by scanning electron microscopy and by microbiological techniques. | 1970 | 5427351 |
| forager size and ecology of acromyrmex coronatus and other leaf-cutting ants in costa rica. | i compare forager size and foraging ecology of the leaf-cutting ant acromyrmex coronatus (fabricius) with published data on three other leaf-cutter species in costa rica, atta cephalotes (l.), acromyrmex octospinosus (reich), and acromyrmex volcanus wheeler. intra-and interspecific differences in forager size in these leaf-cutting ants appear to reflect the economics of harvesting different preferred resources. ac. coronatus colonies have relatively small foragers (mean mass=3.4±1.4 mg) that cut ... | 1995 | 28307655 |
| the evolutionary innovation of nutritional symbioses in leaf-cutter ants. | fungus-growing ants gain access to nutrients stored in plant biomass through their association with a mutualistic fungus they grow for food. this 50 million-year-old obligate mutualism likely facilitated some of these species becoming dominant neotropical herbivores that can achieve immense colony sizes. recent culture-independent investigations have shed light on the conversion of plant biomass into nutrients within ant fungus gardens, revealing that this process involves both the fungal cultiv ... | 2012 | 26467948 |
| leucoagaricus gongylophorus produces diverse enzymes for the degradation of recalcitrant plant polymers in leaf-cutter ant fungus gardens. | plants represent a large reservoir of organic carbon comprised primarily of recalcitrant polymers that most metazoans are unable to deconstruct. many herbivores gain access to nutrients in this material indirectly by associating with microbial symbionts, and leaf-cutter ants are a paradigmatic example. these ants use fresh foliar biomass as manure to cultivate gardens composed primarily of leucoagaricus gongylophorus, a basidiomycetous fungus that produces specialized hyphal swellings that serve ... | 2013 | 23584789 |
| effect of tithonia diversifolia mulch on atta cephalotes (hymenoptera: formicidae) nests. | recent studies have shown an insecticidal effect of tithonia diversifolia (hemsl.) gray (asterales: asteraceae) foliage on workers of atta cephalotes l. and inhibitory effects of this plant on the growth of the symbiotic fungus leucoagaricus gongylophorus (a. müler) singer. to evaluate the potential of t. diversifolia as a biological control treatment of this important pest, we assessed the effect of green manure (mulch) of this plant on natural nests of a. cephalotes, in cali, colombia. three t ... | 2015 | 25843585 |
| enrichment and broad representation of plant biomass-degrading enzymes in the specialized hyphal swellings of leucoagaricus gongylophorus, the fungal symbiont of leaf-cutter ants. | leaf-cutter ants are prolific and conspicuous constituents of neotropical ecosystems that derive energy from specialized fungus gardens they cultivate using prodigious amounts of foliar biomass. the basidiomycetous cultivar of the ants, leucoagaricus gongylophorus, produces specialized hyphal swellings called gongylidia that serve as the primary food source of ant colonies. gongylidia also contain plant biomass-degrading enzymes that become concentrated in ant digestive tracts and are deposited ... | 2015 | 26317212 |
| diversification of the ant odorant receptor gene family and positive selection on candidate cuticular hydrocarbon receptors. | chemical communication plays important roles in the social behavior of ants making them one of the most successful groups of animals on earth. however, the molecular evolutionary process responsible for their chemosensory adaptation is still elusive. recent advances in genomic studies have led to the identification of large odorant receptor (or) gene repertoires from ant genomes providing fruitful materials for molecular evolution analysis. the aim of this study was to test the hypothesis that d ... | 2015 | 26306879 |
| fungal communities in gardens of the leafcutter ant atta cephalotes in forest and cabruca agrosystems of southern bahia state (brazil). | leaf-cutting ants interact with several fungi in addition to the fungal symbiont they cultivate for food. here, we assessed alien fungal communities in colonies of atta cephalotes. fungus garden fragments were sampled from colonies in the atlantic rainforest and in a cabruca agrosystem in the state of bahia (brazil) in two distinct periods to evaluate whether differences in nest habitat influence the diversity of fungi in the ant colonies. we recovered a total of 403 alien fungi isolates from 62 ... | 2015 | 26615740 |
| spatially heterogeneous nest-clearing behavior coincides with rain event in the leaf-cutting ant atta cephalotes (l.) (hymenoptera: formicidae). | leaf-cutting ants of the genus atta construct the probably largest nests among ants and are ecosystem engineers because they alter light and nutrient availability at nest sites. besides creating canopy gaps in the forest, workers remove all vegetation from atop their nest mounds. here, we examined the extent and spatial distribution of this nest-clearing behavior by transplanting licania tomentosa seedlings on atta cephalotes (linnaeus) nest mounds in the atlantic forest in northeast brazil and ... | 2015 | 26013129 |
| the genome sequence of the leaf-cutter ant atta cephalotes reveals insights into its obligate symbiotic lifestyle. | leaf-cutter ants are one of the most important herbivorous insects in the neotropics, harvesting vast quantities of fresh leaf material. the ants use leaves to cultivate a fungus that serves as the colony's primary food source. this obligate ant-fungus mutualism is one of the few occurrences of farming by non-humans and likely facilitated the formation of their massive colonies. mature leaf-cutter ant colonies contain millions of workers ranging in size from small garden tenders to large soldier ... | 2011 | 21347285 |
| association between pseudonocardia symbionts and atta leaf-cutting ants suggested by improved isolation methods. | fungus-growing ants associate with multiple symbiotic microbes, including actinobacteria for production of antibiotics. the best studied of these bacteria are within the genus pseudonocardia, which in most fungus-growing ants are conspicuously visible on the external cuticle of workers. however, given that fungus-growing ants in the genus atta do not carry visible actinobacteria on their cuticle, it is unclear if this genus engages in the symbiosis with pseudonocardia. here we explore whether im ... | 2013 | 24151778 |
| allometric scaling of foraging rate with trail dimensions in leaf-cutting ants. | leaf-cutting ants (atta spp.) create physical pathways to support the transport of resources on which colony growth and reproduction depend. we determined the scaling relationship between the rate of resource acquisition and the size of the trail system and foraging workforce for 18 colonies of atta colombica and atta cephalotes. we examined conventional power-law scaling patterns, but did so in a multivariate analysis that reveals the simultaneous effects of forager number, trail length and tra ... | 2012 | 22337696 |
| chemistry of metapleural gland secretions of three attine ants,atta sexdens rubropilosa, atta cephalotes, andacromyrmex octospinosus (hymenoptera: formicidae). | the chemical composition of the secretions of the metapleural glands of workers and soldiers of twoatta species,atta sexdens rubropilosa anda. cephalotes, and workers ofacromyrmex octospinosus, has been studied. as indicated by infrared spectrometry and confirmed by the ninhydrin test, the secretions contain chiefly proteins. of the volatile acidic portion, which is present as ionized salts, phenylacetic acid is the major component in workers and soldiers ofa. s. rubropilosa anda. cephalotes. bo ... | 1996 | 24227619 |
| ontogenetic changes in forager polymorphism and foraging ecology in the leaf-cutting ant atta cephalotes. | in the leaf-cutting ant atta cephalotes (l.) small colonies produce a relatively narrow size-range of small workers, whereas large colonies produce a much wider size-range of workers. in this study, i compared the foraging of four small a. cephalotes colonies (fewer than 5000 workers) with published data on foraging of large colonies to examine how colony size and worker size-range may be related to foraging ecology in leaf-cutting ants. i found that the foraging ecology of small a. cephalotes c ... | 1994 | 28313983 |
| leaf density and a trade-off between load-size selection and recruitment behavior in the ant atta cephalotes. | this study considers the interplay between individual load-size selection and recruitment behavior in the leaf-cutting ant atta cephalotes. foraging workers anchor themselves on the leaf edge by their hind legs and pivot around them while cutting arcs from leaves. since workers not only cut leaves but also lay chemical trails to recruit nestmates, we investigated whether there is conflict of motivation affecting the workers' decision either to quickly inform nestmates about a newly discovered fo ... | 1994 | 28313583 |
| the effects of light on foliar chemistry, growth and susceptibility of seedlings of a canopy tree to an attine ant. | seedlings of inga oerstediana benth. (mimosaceae) growing in three different light environments (the understory, tree-fall gaps and full sun) were tested for differences in chemistry (nutrients and tannins), wound-induced increases in tannins, growth, and susceptibility to leaf-cutter ants, atta cephalotes (l.) (formicidae: attini). i hypothesized that seedlings of i. oerstediana would contain higher concentrations of tannins when growing in high light conditions and, therefore, would be less su ... | 1991 | 28313337 |
| epiphyll deterrence to the leafcutter ant atta cephalotes. | epiphyll growth on leaves of the grapefruit citrus paradisi and the understory cyclanth cyclanthus bipartitus repelled the fungus-growing, leafcutter ant atta cephalotes from harvesting leaves of these tropical plants. experimental removal of epiphylls from leaves resulted in 2-3 times more herbivore damage by leafcutter ants as compared to matched leaves with epiphylls. because of the protection from herbivore damage, host plants may derive a partial fitness benefit from association with epiphy ... | 1991 | 28313155 |
| leaf processing behaviour in atta leafcutter ants: 90% of leaf cutting takes place inside the nest, and ants select pieces that require less cutting. | leafcutter ants cut trimmings from plants, carry them to their underground nests and cut them into smaller pieces before inoculating them with a fungus that serves as a primary food source for the colony. cutting is energetically costly, so the amount of cutting is important in understanding foraging energetics. estimates of the cutting density, metres of cutting per square metre of leaf, were made from samples of transported leaf cuttings and of fungal substrate from field colonies of atta ceph ... | 2016 | 26909161 |
| synthesis of the enantiomers of tedanalactam and the first total synthesis and configurational assignment of (+)-piplaroxide. | highlighting the recently established methodology for the direct synthesis of glycidic amides from tertiary allyl amines, the synthesis of the enantiomers of tedanalactam were completed in two steps from the corresponding chiral dihydropiperidine. additionally, the (+)- and (-)-enantiomers of piplaroxide were obtained from their respective tedanalactam precursor, and the absolute configuration of the naturally occurring (+)-piplaroxide was determined. the present approach represents not only the ... | 2016 | 26913637 |
| new caffeic acid derivative from tithonia diversifolia (hemsl.) a. gray butanolic extract and its antioxidant activity. | tithonia diversifolia, asteraceae, a promising alternative for insect control such as leaf-cutting ants, have revealed repellent and insecticidal activity against atta cephalotes. the different biological activities of t. diversifolia, are due to the existence of sesquiterpene lactones and phenolic compounds. some phenolic compounds have antioxidant activity and curiously also exhibited tyrosinase inhibitory activity, key enzyme in insect metamorphosis. to expand the plant phytochemical knowledg ... | 2017 | 28365409 |
| branch width and height influence the incorporation of branches into foraging trails and travel speed in leafcutter ants atta cephalotes (l.) (hymenoptera: formicidae). | fallen branches are often incorporated into atta cephalotes (l.) foraging trails to optimize leaf tissue transport rates and economize trail maintenance. recent studies in lowlands show laden a. cephalotes travel faster across fallen branches than on ground, but more slowly ascending or descending a branch. the latter is likely because (1) it is difficult to travel up or downhill and (2) bottlenecks occur when branches are narrower than preceding trail. hence, both branch height and width should ... | 2016 | 26830434 |
| host-plant selection, diet diversity, and optimal foraging in a tropical leafcutting ant. | a month-long study was conducted on the comparative foraging behavior of 20 colonies of the leafcutting ant, atta cephalotes l. in santa rosa national park, guanacaste province, costa rica. the study was conducted during the middle of the wet season, when trees had mature foliage and the ants were maximally selective among species of potential host plants. the colonies always gathered leaves from more than a single tree species but on average one species constituted almost half the diet with the ... | 1987 | 28310414 |
| an antifungal terpenoid defends a neotropical tree (hymenaea) against attack by fungus-growing ants (atta). | foragers of the leafcutting ant, atta cephalotes l. (formicidae, attini) seldom or never attack many of the plant species available to them in nature. in the semideciduous forests of lowland guanacaste province, costa rica, one of the tree species seldom cut is hymenaea courbaril l. (leguminosae, caesalpinioideae). we tested the hypothesis that this species is avoided by the ants because of the presence of ant-repellent secondary compounds in the leaves. a bioassay to test repellency of leaf ext ... | 1983 | 28310690 |