Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| scaling of differentiation in networks: nervous systems, organisms, ant colonies, ecosystems, businesses, universities, cities, electronic circuits, and legos. | nodes in networks are often of different types, and in this sense networks are differentiated. here we examine the relationship between network differentiation and network size in networks under economic or natural selective pressure, such as electronic circuits (networks of electronic components), legos (networks of lego pieces), businesses (networks of employees), universities (networks of faculty), organisms (networks of cells), ant colonies (networks of ants), and nervous systems (networks o ... | 2002 | 12381294 |
| calibration processes in desert ant navigation: vector courses and systematic search. | this study investigates the ability of desert ants to adapt their path integration system to an "open-jaw" training paradigm, in which the point of arrival (from the nest) does not coincide with the point of departure (to the nest). upon departure the ants first run off their home vector and then start a systematic search for the nest. even if they are subjected to this training-around-a-circuit procedure for more than 50 times in succession, they never adopt straight homeward courses towards th ... | 2002 | 12397439 |
| reduction of brain volume correlates with behavioral changes in queen ants. | the behavior of reproductive female ants distinctly changes during the transition from virgin to mature, egg-laying queen. a winged female ant flies only once during her lifetime when she engages in the nuptial flight. once she is mated she sheds her wings, excavates a nest and starts laying eggs, the basis for her future colony. we show for two species of harvester ants that this transition is accompanied by changes in the performance of behavioral tests: flying virgins are positively phototact ... | 2002 | 12417820 |
| severe human urticaria produced by ant (odontomachus bauri, emery 1892) (hymenoptera: formicidae) venom. | ant sting reactions are becoming an increasing problem in tropical countries. it is important for physicians to be aware of their possible cutaneous and systemic manifestations. | 2002 | 12453010 |
| trail pheromone of ponerine ant gnamptogenys striatula: 4-methylgeranyl esters from dufour's gland. | dufour's gland is the origin of the trail pheromone of gnamptogenys striatula. chemical analysis of the glandular extracts revealed a series of new natural products, especially esters of (2e)-3,4,7-trimethyl-2,6-octadien-1-ol (4-methylgeraniol), and (2e)-3,4,7-trimethyl-2,6-nonadien-1-ol (a bishomogeraniol isomer) with medium-chain fatty acids. bioassays with synthetic racemates of the esters revealed that the 4-methylgeranyl esters are highly active as trail pheromones, while the bishomogeranyl ... | 2002 | 12564800 |
| cuticular hydrocarbons of tetramorium ants from central europe: analysis of gc-ms data with self-organizing maps (som) and implications for systematics. | cuticular hydrocarbons were extracted from workers of 63 different nests of five species of tetramorium ants (hymenoptera: formicidae) from austria, hungary, and spain. the gc-ms data were classified (data mining) by self-organizing maps (som). som neurons derived from primary neuron separation were subjected to hierarchical som (hsom) and were grouped to neuron areas on the basis of vicinity in the hexagonal output grid. while primary neuron separation and hsom resulted in classifications on a ... | 2002 | 12564801 |
| semiochemicals released by electrically stimulated red imported fire ants, solenopsis invicta. | the red imported fire ant solenopsis invicta buren, has evolved sophisticated chemical communication systems that regulate the activities of the colony. among these are recruitment pheromones that effectively attract and stimulate workers to follow a trail to food or alternative nesting sites. alarm pheromones alert, activate, and attract workers to intruders or other disturbances. the attraction and accumulation of fire ant workers in electrical equipment may be explained by their release of ph ... | 2002 | 12564802 |
| 1-octen-3-ol together with geosmin: new secretion compounds from a polydesmid millipede, niponia nodulosa. | the small millipede niponia nodulosa (polydesmida: cryptodesmidae) emits an earthy smell when disturbed. this smell was obtained from hexane extracts from both sexes at the sixth and seventh instars and adult stages, and was found by gc/ms analyses to be composed of two compounds, 1-octen-3-ol as the major component and geosmin as the minor component. this is the first report of these compounds in secreted substances from millipedes. as they showed little repellent activity against foraging ants ... | 2002 | 12564803 |
| the fire ant wars. nature and science in the pesticide controversies of the late twentieth century. | this essay uses an approach borrowed from environmental history to investigate the interaction of science and nature in a late twentieth-century controversy. this debate, over the proper response to fire ants that had been imported into the american south accidentally and then spread across the region, pitted rachel carson and loosely federated groups of conservationists, scientists, and citizens against the u.s. department of agriculture. the analysis falls into three sections: an examination o ... | 2002 | 12592885 |
| nestmate recognition signals of the leaf-cutting ant atta laevigata. | behavioral tests with field colonies of atta laevigata were performed in order to identify the source of the odors used in nestmate recognition. we tested the postpharyngeal (ppg) and mandibular glands (mg) as putative organs producing chemical signals for nestmate recognition. chemical analyses of ppg were also undertaken. with a series of bioassays, we confirmed that nestmate recognition is based on cephalic odors and that these odors come mainly from the mandibular gland secretion. we show ch ... | 2002 | 12770102 |
| age-specific patterns in honeydew production and honeydew composition in the aphid metopeurum fuscoviride: implications for ant-attendance. | the intensity of the mutualistic relationship between aphids and ants depends mainly on the composition and amount of honeydew. we used the model system tanacetum vulgare-metopeurum fuscoviride to study age-related differences in honeydew production and composition and its effect on the mutualism between m. fuscoviride and the ant lasius niger. first and second instar larvae of m. fuscoviride produced only half of the amount of honeydew as older larvae or adults. there were, however, no differen ... | 2002 | 12770106 |
| motor control of the mandible closer muscle in ants. | despite their simple design, ant mandible movements cover a wide range of forces, velocities and amplitudes. the mandible is controlled by the mandible closer muscle, which is composed of two functionally distinct subpopulations of muscle fiber types: fast fibers (short sarcomeres) and slow ones (long sarcomeres). the entire muscle is controlled by 10-12 motor neurons, 4-5 of which exclusively supply fast muscle fibers. slow muscle fibers comprise a posterior and an antero-lateral group, each of ... | 2002 | 12770126 |
| the natural history of the arboreal ant, crematogaster ashmeadi. | the arboreal ant, crematogaster ashmeadi emery (hymenoptera: formicidae), is the most dominant arboreal ant in the pine forests of the coastal plain of northern florida. the majority of pine trees harbor a colony of these ants. the colonies inhabit multiple chambers abandoned by bark-mining caterpillars, especially those of the family cossidae, in the outer bark of living pines. they also inhabit ground level termite galleries in the bark, often locating the queen in galleries. the density of ch ... | 2002 | 15455046 |
| a quantification of predation rates, indirect positive effects on plants, and foraging variation of the giant tropical ant, paraponera clavata. | while a clear consensus is emerging that predators can play a major role in shaping terrestrial communities, basic natural history observations and simple quantifications of predation rates in complex terrestrial systems are lacking. the potential indirect effect of a large predatory ant, paraponera clavata fabricius (formicidae: ponerinae), on herbivores was determined on rainforest trees at la selva biological station in costa rica and barro colorado island in panama. prey and other food broug ... | 2002 | 15455052 |
| ant versus fungus versus mutualism: ant-cultivar conflict and the deconstruction of the attine ant-fungus symbiosis. | a century of research on fungus-growing ants (attini, formicidae) has ignored the cultivated fungi as passive domesticates and viewed the attine fungicultural symbiosis as an integrated unit dominated by the evolutionary interests of the ant farmers. this article takes a different perspective and explores first the evolutionary interests and leverages of the fungal cultivars, then dissects eight potential evolutionary conflicts between ants and cultivars. three types of ant-cultivar conflict are ... | 2002 | 18707454 |
| 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 |
| population ecology, nonlinear dynamics, and social evolution. i. associations among nonrelatives. | using an individual-based and genetically explicit simulation model, we explore the evolution of sociality within a population-ecology and nonlinear-dynamics framework. assuming that individual fitness is a unimodal function of group size and that cooperation may carry a relative fitness cost, we consider the evolution of one-generation breeding associations among nonrelatives. we explore how parameters such as the intrinsic rate of growth and group and global carrying capacities may influence s ... | 2002 | 18707408 |
| segmental specializations in the malpighian tubules of the fire ant solenopsis saevissima forel 1904 (myrmicinae): an electron microscopical study. | the malpighian tubules of workers of the fire ant solenopsis saevissima (myrmicinae) were analyzed by scanning and transmission electron microscopy in order to determine their functional organization and association with the hindgut epithelium. the ants showed six malpighian tubules with three segments morphologically and structurally different. the proximal segment was long and its cells showed abundant smooth endoplasmic reticulum and lipid droplets, which suggest their role in lipid secretion ... | 2002 | 18088962 |
| an integrative study of insect adhesion: mechanics and wet adhesion of pretarsal pads in ants. | many animals that locomote by legs possess adhesive pads. such organs are rapidly releasable and adhesive forces can be controlled during walking and running. this capacity results from the interaction of adhesive with complex mechanical systems. here we present an integrative study of the mechanics and adhesion of smooth attachment pads (arolia) in asian weaver ants (oecophylla smaragdina). arolia can be unfolded and folded back with each step. they are extended either actively by contraction o ... | 2002 | 21680393 |
| floral biology and unique pollination system of root holoparasites, balanophora kuroiwai and b. tobiracola (balanophoraceae). | we investigated the floral and pollination biology of two monoecious root holoparasites, balanophora kuroiwai and b. tobiracola (balanophoraceae), in the subtropical forests of southern japan. both species secrete nectar from extrafloral nectaries distributed among the flowers, which is mainly consumed by ants, cockroaches, and pyralid moths. pollen grains were found attached to the bodies of these insects. pyralid moths of the genera assara and nacoleia were observed laying eggs on the inflores ... | 2002 | 21665716 |
| 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 |
| female reproductive system of the decapitating fly pseudacteon wasmanni schmitz (diptera: phoridae). | pseudacteon wasmanni is a south american decapitating fly that parasitizes workers of solenopsis fire ants. we used light microscopy (historesin serial-sectioning stained with haematoxylin/eosin) and scanning electron microscopy to show and analyze internal and whole external views of the female reproductive system. all specimens analyzed (n=9) by light microscopy showed post-vitellogenic oocytes inside the ovaries. the lack of typical follicles (oocyte-nurse cell complexes) in all specimens sug ... | 2003 | 18088990 |
| development of the labial gland of the ponerine ant pachycondyla obscuricornis (hymenoptera, formicidae) during the pupal stage. | the labial gland of adult workers of the ant pachycondyla obscuricornis is made up of many acini, each consisting of one central cell surrounded by approximately 10 parietal cells. both cell types are associated with a system of ramified canaliculi that remove the secretion towards a ductule outside the acinus. these ductules, each associated with one acinus, fuse together and form a ramified system of ducts, ending in two paired ducts. these paired ducts widen to form a reservoir and anteriorly ... | 2003 | 18089006 |
| ant community change across a ground vegetation gradient in north florida's longleaf pine flatwoods. | ant communities in longleaf pine habitats are poorly known and hence the naturally occurring ant assemblages of a large portion of southeastern north america are not well understood. this study examined the diverse ant community found in the longleaf pine flatwoods of north florida and tested how ant diversity changes along a herbaceous ground cover gradient. restoring the ground cover to its original floral composition is an important focus of longleaf pine conservation and hence it is importan ... | 2003 | 15841237 |
| automatic life-long monitoring of individual insect behaviour now possible. | automatic tracking and identification of individuals has the potential to revolutionize the study of insects, especially social insects, by opening up options for questions which could not be asked before. to achieve this we developed a reliable and cost-sensible rfid (radio-frequency identification) based solution that automatically recognises a virtually unlimited number (18 x 10(18) possible id numbers) of individual insects down to the size of bees and ants. the data are collected automatica ... | 2003 | 16351902 |
| invasive argentine ants (linepithema humile) do not replace native ants as seed dispersers of dendromecon rigida (papaveraceae) in california, usa. | we investigated the indirect effects of argentine ant (linepithema humile) invasions on patterns of seed dispersal and predation in the myrmecochorous tree poppy dendromecon rigida in coastal san diego county, california. significantly more seeds were removed from ant-accessible seed stations at sites numerically dominated by a common harvester ant (pogonomyrmex subnitidus), a native disperser of these seeds and a species sensitive to displacement by l. humile, than from those stations at sites ... | 2003 | 16228256 |
| the venom alkaloids from some african monomorium species. | a comparative analysis of the venom alkaloids of 13 species of ants in the genus monomorium collected in africa was undertaken. ants were collected in kenya and south africa. most species produced 2,5-dialkylpyrrolidines and some of their analogous 1-pyrrolines. no alkaloids were detected in two species. m. robustior and m. macrops. additionally, a novel 2-alkyl-1-pyrroline, whose structure was established by synthesis, was detected in m. notulum. this compound and others like it may serve as bi ... | 2003 | 14969358 |
| hierarchical analysis of colony and population genetic structure of the eastern subterranean termite, reticulitermes flavipes, using two classes of molecular markers. | termites (isoptera) comprise a large and important group of eusocial insects, yet, in contrast to the eusocial hymenoptera (ants, bees, wasps), the breeding systems of termites remain poorly understood. in this study, i inferred the breeding system of the subterranean termite reticulitermes flavipes based on colony and population genetic structure as determined from microsatellite and mitochondrial dna markers. termites were sampled from natural wood debris from three undisturbed, forested sites ... | 2003 | 14761059 |
| insect faunal succession on decaying rabbit carcasses in punjab, india. | insect faunal succession on decaying rabbit carcasses was carried out at punjabi university, patiala (punjab), india, from march 1997 to december 1999. four stages of decomposition were recognized, i.e., fresh, bloated, decay, and dry. a total of 38 insect species belonging to four orders and 13 families were recorded. diptera, coleoptera, and hymenoptera dominated the carrion fauna. calliphorids were the first to arrive in all the seasons of the year. five species of calliphoridae, four of sarc ... | 2003 | 14535681 |
| use of ribosomal dna sequence data to characterize and detect a neogregarine pathogen of solenopsis invicta (hymenoptera: formicidae). | a neogregarine parasite of the red imported fire ant, solenopsis invicta, was discovered recently in florida and tentatively placed in the mattesia genus based on morphological characterization. s. invicta infected with this mattesia species exhibited a characteristic yellowing of the cuticle which was designated mattesia "yellow-head disease" (yhd). the 18s rrna gene sequence from mattesia yhd was elucidated and compared with the neogregarine pathogens, mattesia geminata and ophriocystis elektr ... | 2003 | 14615220 |
| alternative genetic foundations for a key social polymorphism in fire ants. | little is known about the genetic foundations of colony social organization. one rare example in which a single major gene is implicated in the expression of alternative social organizations involves the presumed odorant-binding protein gene gp-9 in fire ants. specific amino acid substitutions in this gene invariably are associated with the expression of monogyny (single queen per colony) or polygyny (multiple queens per colony) in fire ant species of the solenopsis richteri clade. these substit ... | 2003 | 14704171 |
| gnamptogenys hartmani wheeler (ponerinae: ectatommini): an agro-predator of trachymyrmex and sericomyrmex fungus-growing ants. | the fungus gardens of fungus-growing ants are a potentially valuable resource for exploitation by natural enemies, but few of these antagonistic interactions have been studied. here we describe key aspects of the behavioral ecology of gnamptogenys hartmani (ponerinae: ectatommini), a specialized "agro-predator" of trachymyrmex and sericomyrmex fungus-growing ants in panama. raiding columns of g. hartmani attack and usurp nests with remarkably little effort: a few intruding workers are sufficient ... | 2003 | 14676954 |
| route learning by insects. | ants and other insects often follow fixed routes from their nest to a foraging site. the shape of an ant's route is set, initially, by navigational strategies, such as path integration and the ant's innate responses to landmarks, which depend minimally on memory. with increasing experience, these early routes are stabilised through the learning of views of landmarks and of associated actions. the substitution of memory-based strategies makes an insect's route more robust and precise. the ability ... | 2003 | 14662374 |
| the infrabuccal pellet piles of fungus-growing ants. | fungus-growing ants (attini) live in an obligate mutualism with the fungi they cultivate for food. because of the obligate nature of this relationship, the success of the ants is directly dependent on their ability to grow healthy fungus gardens. attine ants have evolved complex disease management strategies to reduce their garden's exposure to potential parasitic microbes, to prevent the establishment of infection in their gardens, and to remove infected garden sections. the infrabuccal pocket, ... | 2003 | 14676952 |
| influence of insecticide treatments on ant-hemiptera associations in tropical plantations. | in this survey conducted in southern cameroon, we compared ant-hemiptera associations on plantations treated with insecticides, on plantations 2 years after insecticide treatments ceased, and on control lots that never received insecticide treatments. by eliminating arboreal-nesting ants, insecticides favored the presence of "ecologically dominant" ground-nesting, arboreal-foraging species that occupied the tree crowns. the reinstallation of arboreal ants was slow as 2 yr after insecticide treat ... | 2003 | 14994787 |
| localized scalp hair shedding caused by pheidole ants and overwiew of similar case reports. | localized hair shedding caused by pheidole ants is reported as a newly recognized type of hair loss, mimicking alopecia areata. we report two cases from kerman, iran. this sudden hair loss demonstrates that ants such as the pheidole dimorphic species can cause hair shedding. fairly clean cutting of the scalp hair takes place just a few micrometers above the skin surface and simulates alopecia areata or mechanical shaving of scalp hair. this infestation has not been reported from other countries, ... | 2003 | 12952759 |
| queen size mediates queen survival and colony fitness in harvester ants. | we examined the effect of queen size on the probability of new colony establishment in the ant pogonomyrmex occidentalis. large queens are significantly more likely to survive than small queens through the initial stages of colony founding. these differences in individual fitness correlates have corresponding effects on colony fitness. in species in which individual queens vary in fitness, sexual allocation ratios should incorporate the individual fitness functions. | 2003 | 14575338 |
| purification, biochemical characterization, and cdna cloning of a glutathione s-transferase from the red imported fire ant, solenopsis invicta. | a glutathione s-transferase (gst) was purified 266-fold from adult workers of the red imported fire ant, solenopsis invicta (hymenoptera: formicidae) by affinity chromatography and preparative isoelectric focusing. the purified enzyme appeared as a single band on sds-page and had a mr of 25.5 kda. steady state kinetics assays of the enzyme with 1-chloro-2,4-dinitrobenzene as substrate were conducted. the vmax, km cdnb, km gsh, kcat, kcat/km cdnb, and kcat/km gsh for the purified fire ant gst wer ... | 2003 | 14505691 |
| speed versus accuracy in collective decision making. | we demonstrate a speed versus accuracy trade-off in collective decision making. house-hunting ant colonies choose a new nest more quickly in harsh conditions than in benign ones and are less discriminating. the errors that occur in a harsh environment are errors of judgement not errors of omission because the colonies have discovered all of the alternative nests before they initiate an emigration. leptothorax albipennis ants use quorum sensing in their house hunting. they only accept a nest, and ... | 2003 | 14667335 |
| worker policing without genetic conflicts in a clonal ant. | in group-living animals, mutual policing to suppress reproduction is an important mechanism in the resolution of conflict between selfish group members and the group as a whole. in societies of bees, ants, and wasps, policing against the production of males by other workers is expected when egg laying by workers decreases the average inclusive fitness of individual group members. this may result (i) from the relatedness of workers being lower to worker than to queen-derived males or (ii) from a ... | 2003 | 14557542 |
| army ants trapped by their evolutionary history. | 2003 | 14624241 | |
| ability of canine termite detectors to locate live termites and discriminate them from non-termite material. | dogs were trained to detect eastern subterranean termites, reticulitermes flavipes (kollar), using the united states customs method of scent detection dog training modified with a food reward. dogs were tested with various numbers of eastern subterranean termites placed in vented pvc containers. trained dogs were 95.93% accurate in finding > or = 40 eastern subterranean termite workers (positive indications) and incorrectly indicated the presence of termites in 2.69% of the containers without te ... | 2003 | 14503599 |
| mitochondrial adenine nucleotide translocator 3 is regulated by il-4 and ifn-gamma via stat-dependent pathways. | il-4 and ifn-gamma are prototypical th2 and th1 cytokines, respectively. they reciprocally regulate a number of genes involved in th1 vs th2 immune balance. using dd-pcr analysis, adenine nucleotide translocase (ant) 3, an enzyme which exchanges atp and adp through mitochondrial membrane, has been identified as a novel target counter-regulated by il-4 and ifn-gamma. we have observed that il-4 and ifn-gamma each up-regulates ant3 in t cells both at mrna and protein levels, while cotreatment of il ... | 2003 | 14746803 |
| the genome sequence of blochmannia floridanus: comparative analysis of reduced genomes. | bacterial symbioses are widespread among insects, probably being one of the key factors of their evolutionary success. we present the complete genome sequence of blochmannia floridanus, the primary endosymbiont of carpenter ants. although these ants feed on a complex diet, this symbiosis very likely has a nutritional basis: blochmannia is able to supply nitrogen and sulfur compounds to the host while it takes advantage of the host metabolic machinery. remarkably, these bacteria lack all known ge ... | 2003 | 12886019 |
| field evaluation of the bait toxicant chlorfluazuron in eliminating coptotermes acinaciformis (froggatt) (isoptera: rhinotermitidae). | two aspects of the exterra termite interception and baiting system (ensystex, fayetteville, nc) were evaluated in a field experiment using 13 termite mounds near townsville, australia. first, a cellulose-acetate powder containing either 0.05% wt:wt or 0.25% wt:wt chlorfluazuron (requiem, ensystex, fayetteville, nc) was tested for its efficacy in eliminating colonies of the xylophagous mound-building subterranean termite coptotermes acinaciformis (froggatt). the moist bait matrix was replenished ... | 2003 | 14977122 |
| optimization, conflict, and nonoverlapping foraging ranges in ants. | an organism's foraging range depends on the behavior of neighbors, the dynamics of resources, and the availability of information. we use a well-studied population of the red harvester ant pogonomyrmex barbatus to develop and independently parameterize models that include these three factors. the models solve for an allocation of foraging ants in the area around the nest in response to other colonies. we compare formulations that optimize at the colony or individual level and those that do or do ... | 2003 | 14618533 |
| complex hybrid origin of genetic caste determination in harvester ants. | caste differentiation and division of labour are the hallmarks of insect societies and at the root of their ecological success. kin selection predicts that caste determination should result from environmentally induced differences in gene expression, a prediction largely supported by empirical data. however, two exceptional cases of genetically determined caste differentiation have recently been found in harvester ants. here we show that genetic caste determination evolved in these populations a ... | 2003 | 12867980 |
| the role of anthracyclines in second-line therapy of ovarian cancer. | anthracyclines (ants) have been in clinical practice since the 1960s and represent one of the most commonly used classes of anticancer drugs. in the 1990s, meta-analyses showed a favorable impact of doxorubicin (dox/a) on the survival of patients with advanced ovarian cancer, when it was combined with cyclophosphamide and cisplatin (cap) and compared to cp alone. with the acceptance of paclitaxel-carboplatin (tcb) as the new reference arm for first-line treatment, testing the addition of ants to ... | 2003 | 14656277 |
| olfactive detection of fig wasps as prey by the ant crematogaster scutellaris (formicidae; myrmicinae). | in the species-specific and obligate mutualism between the fig (ficus carica) and its pollinator (the fig wasps blastophaga psenes), a third participant, the ant crematogaster scutellaris, is a predator of the wasps. here, we ask how ant workers can rapidly localise such prey, whose availability is limited in time and space. using a y-tube olfactometer, we tested ant response to odours emitted by different types of figs (receptive female, ripe female or male figs) and by fig wasps (pollinators o ... | 2003 | 14564404 |
| residual susceptibility of the red imported fire ant (hymenoptera: formicidae) to four agricultural insecticides. | the red imported fire ant, solenopsis invicta buren, is an abundant predator in cropping systems throughout its range. it has been documented to be an important predator of numerous crop pests, as well as being an agricultural pest itself. information on the impact of insecticides on natural enemies such as fire ants is necessary for the integration of biological and chemical control tactics in an effective pest management program. therefore, a residual vial bioassay was developed to determine t ... | 2003 | 12852600 |
| multiple, recurring origins of aposematism and diet specialization in poison frogs. | aposematism is the association, in a prey organism, of the presence of a warning signal with unprofitability to predators. the origin of aposematism is puzzling, because of its predicted low probability of establishment in a population due to the prey's increased conspicuousness. aposematism is a widespread trait in invertebrate taxa, but, in vertebrates, it is mostly evident in amphibians, reptiles, and fishes. poison frogs (dendrobatidae) are one of the most well known examples of the co-occur ... | 2003 | 14555763 |
| auguste forel on ants and neurology. | auguste forel was born in 1848 in the french part of switzerland. he developed a lifelong passion for myrmecology in his childhood, but chose medicine and neuropsychiatry to earn his living. he first undertook a comparative study of the thalamus under theodor meynert in vienna and then, from 1872 to 1879, he worked as assistant physician to bernhard von gudden in munich. this led in 1877 to his seminal work on the organization of the tegmental region in which he provides the first description of ... | 2003 | 12945958 |
| history and the global ecology of squamate reptiles. | the structure of communities may be largely a result of evolutionary changes that occurred many millions of years ago. we explore the historical ecology of squamates (lizards and snakes), identify historically derived differences among clades, and examine how this history has affected present-day squamate assemblages globally. a dietary shift occurred in the evolutionary history of squamates. iguanian diets contain large proportions of ants, other hymenopterans, and beetles, whereas these are mi ... | 2003 | 12856236 |
| chemical composition and biological activity of nepeta parnassica oils and isolated nepetalactones. | essential oils of nepeta parnassica, collected at different developmental stages, were analyzed by means of gc/ms. from the fifty-five identified constituents in samples a and b, representing 94.8% and 98.7% of the oils respectively, 4a(alpha),7alpha,7alpha(beta)-nepetalactone (22.0%), 1,8-cineole (21.1%), alpha-pinene (9.5%) and 4a(alpha),7,beta,7alpha(beta)-nepetalactone (7.9%) were the major components of sample a (vegetative stage), whereas in sample b (flowering stage) the main contributors ... | 2003 | 14577631 |
| patterns of venom synthesis and use in the fire ant, solenopsis invicta. | in the life of the fire ant, solenopsis invicta, venom plays several important roles, including prey capture, defense, and anti-microbial action. although this venom's chemistry, pharmacology, and effects on humans have been extensively studied, its patterns of synthesis and use have not. we determined the ability of different-aged workers to synthesize venom, and measured the amount of venom workers delivered per sting. newly eclosed workers contained little or no venom in their reservoirs. the ... | 2003 | 14602123 |
| prevention of anaphylaxis with ant venom immunotherapy. | worldwide, eight genera of ants have been associated with sting allergy. until recently only whole ant body extracts have been used for immunotherapy. the purpose of this review is to examine recent advances in the understanding of ant venom allergy and treatment using venom immunotherapy. | 2003 | 14612677 |
| ants join online colony to boost conservation efforts. | 2003 | 12867945 | |
| worker caste polymorphism has a genetic basis in acromyrmex leaf-cutting ants. | division of labor is fundamental to the success of all societies. the most striking examples are the physically polymorphic worker castes in social insects with clear morphological adaptations to different roles. these polymorphic worker castes have previously been thought to be a classic example of nongentically controlled polymorphism, being mediated entirely by environmental cues. here we show that worker caste development in the leaf-cutting ant acromyrmex echinatior has a significant geneti ... | 2003 | 12878720 |
| disentangling a rainforest food web using stable isotopes: dietary diversity in a species-rich ant community. | for diverse communities of omnivorous insects such as ants, the extent of direct consumption of plant-derived resources vs. predation is largely unknown. however, determination of the extent of "herbivory" among ants may be crucial to understand the hyper-dominance of ants in tropical tree crowns, where prey organisms tend to occur scarcely and unpredictably. we therefore examined n and c stable isotope ratios (delta(15)n and delta(13)c) in 50 ant species and associated insects and plants from a ... | 2003 | 12898386 |
| the distribution and evolutionary history of wolbachia infection in native and introduced populations of the invasive argentine ant (linepithema humile). | wolbachia pipientis is a maternally transmitted bacterium that often alters the life history of its insect host to maximize transmission to subsequent generations. here we report on the frequency and distribution of wolbachia infection in a widespread invasive species, the argentine ant (linepithema humile). we screened 1175 individual argentine ants from 89 nests on five continents and several islands, including numerous locations in both the native (south american) and introduced ranges. we de ... | 2003 | 14629385 |
| caste fate conflict in swarm-founding social hymenoptera: an inclusive fitness analysis. | a caste system in which females develop into morphologically distinct queens or workers has evolved independently in ants, wasps and bees. although such reproductive division of labour may benefit the colony it is also a source of conflict because individual immature females can benefit from developing into a queen in order to gain greater direct reproduction. here we present a formal inclusive fitness analysis of caste fate conflict appropriate for swarm-founding social hymenoptera. three major ... | 2003 | 14632228 |
| ecology, life history and resource allocation in the ant, leptothorax nylanderi. | we aimed at identifying the causal basis of previously shown interrelations between demographic and genetic colony structure, ecological factors and split sex ratios in the ant, leptothorax nylanderi. colony-level variation in sex allocation was only partly explained by annual fluctuations during eight study years and by resource availability as indicated by sexual production of colonies. allocation ratios were highly male-biased in dense populations with ephemeral nest sites and high frequencie ... | 2003 | 14632230 |
| evolution of the army ant syndrome: the origin and long-term evolutionary stasis of a complex of behavioral and reproductive adaptations. | the army ant syndrome of behavioral and reproductive traits (obligate collective foraging, nomadism, and highly specialized queens) has allowed these organisms to become the premiere social hunters of the tropics, yet we know little about how or why these strategies evolved. the currently accepted view holds that army ants evolved multiple times on separate continents. i generated data from three nuclear genes, a mitochondrial gene, and morphology to test this hypothesis. results strongly indica ... | 2003 | 12750466 |
| dispersion movements in ants: spatial structuring and density-dependent effects. | this paper examines whether the characteristics of individual dispersion movements in ants are changed when workers are moving solitarily or in a group. we analyzed the trajectories of workers of the species messor sancta moving solitarily or in groups of different size (5, 10, 15 individuals), tested for density-dependent effects on their trajectory characteristics and investigated through resampling techniques whether ants are able to spatially structure their movements through direct (e.g. co ... | 2003 | 12763266 |
| regulation of ants' foraging to resource productivity. | we investigate the behavioural rule used by ant societies to adjust their foraging response to the honeydew productivity of aphids. when a scout finds a single food source, the decision to lay a recruitment trail is an all-or-none response based on the opportunity for this scout to ingest a desired volume acting as a threshold. here, we demonstrate, through experimental and theoretical approaches, the generic value of this recruitment rule that remains valid when ants have to forage on multiple ... | 2003 | 12908982 |
| colony structure in a plant-ant: behavioural, chemical and genetic study of polydomy in cataulacus mckeyi (myrmicinae). | social organisation of colonies of obligate plant-ants can affect their interaction with myrmecophyte hosts and with other ants competing for the resources they offer. an important parameter of social organisation is whether nest sites of a colony include one or several host individuals. we determined colony boundaries in a plant-ant associated with the rainforest understorey tree leonardoxa africana subsp. africana, found in coastal forests of cameroon (central africa). this myrmecophyte is str ... | 2003 | 12910408 |
| collective specification of cellular development. | studies of chimeras and in vivo development demonstrate that cell lineages are often quite variable, apparently in response to chance perturbations. this points to an apparent contradiction: although individual cells are the units of genetic information and differentiation, not all cellular events need be precise for the development of functional organisms. the social organization of ants can serve as a metaphor that helps understand the mechanisms that underlie such development. ants suggest th ... | 2003 | 12938179 |
| inbreeding and sex-biased gene flow in the ant formica exsecta. | the objective of this study was to assess breeding and dispersal patterns of both males and females in a monogyne (a single queen per colony) population of ants. monogyny is commonly associated with extensive nuptial flights, presumably leading to considerable gene flow over large areas. opposite to these expectations we found evidence of both inbreeding and sex-biased gene flow in a monogyne population of formica exsecta. we found a significant degree of population subdivision at a local scale ... | 2003 | 12940360 |
| effects of decomposition on carcass attendance in a guild of carrion-breeding flies. | many forensically important calliphorids, sarcophagids and muscids (diptera) oviposit or larviposit on corpses only during the early stages of decomposition, yet individuals may attend bodies throughout decay. a field study was conducted to investigate how patterns of carcass use and attendance by some fly species are affected by decomposition. five fly traps were placed in the forest and baited with whole, fresh piglet carcasses. piglets decomposed in traps throughout the experiment, and all we ... | 2003 | 12941010 |
| optimality of collective choices: a stochastic approach. | amplifying communication is a characteristic of group-living animals. this study is concerned with food recruitment by chemical means, known to be associated with foraging in most ant colonies but also with defence or nest moving. a stochastic approach of collective choices made by ants faced with different sources is developed to account for the fluctuations inherent to the recruitment process. it has been established that ants are able to optimize their foraging by selecting the most rewarding ... | 2003 | 12909251 |
| colony behavior of atta sexdens rubropilosa (hymenoptera: formicidae) in the absence of the queen under laboratory conditions. | a colony of atta sexdens rubropilosa was studied in the presence and absence of the queen. the frequency of 23 previously defined behaviors was quantified in terms of average frequencies of act occurrence. colony behavioral activities such as foraging, fungal care, and refuse manipulation were not directly influenced by the queen's presence up to 30 days after the queen's death. the queen, which also seems to maintain colony cohesion aside from reproduction, indirectly affected brood care. | 2003 | 12914995 |
| 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 |
| sex-ratio dependent execution of queens in polygynous colonies of the ant formica exsecta. | formica exsecta has become an important model system for studying intraspecific variation in sex ratios. patterns of sex allocation in polygynous (multiple queen per nest) populations of f. exsecta are generally consistent with the queen-replenishment hypothesis. this hypothesis states that colonies produce gynes (reproductive females) in order to increase queen number and enhance colony survival and/or productivity when the number of resident queens is low. however, the small proportion of colo ... | 2003 | 12647173 |
| cuticular hydrocarbons mediate discrimination of reproductives and nonreproductives in the ant myrmecia gulosa. | in many species of social insects, the cuticular hydrocarbons of adults vary with both colony identity and individual physiology (oogenesis). such variations have been shown in some ants and social wasps to function in nestmate recognition, but as yet there is no demonstration of their use by workers to recognize egg layers. we report that in the ant myrmecia gulosa, workers can discriminate queens and fertile workers from infertile individuals based on distinctive blends of long-chained hydroca ... | 2003 | 12920186 |
| uruguay: ants versus elephants. | 2003 | 12773719 | |
| determinants of intracolonial relatedness in pogonomyrmex rugosus (hymenoptera; formicidae): mating frequency and brood raids. | the genus pogonomyrmex is one of three ant genera with an effective mating frequency (me) > 2.0. we developed microsatellites to determine me for p. rugosus because mating frequency of p. rugosus was known only from observational data which do not allow an estimate of me. we genotyped 474 workers from 20 colonies for two microsatellite loci. observed mating frequencies ranged from 3 to 12 and me for p. rugosus was 4.71. observed patriline frequencies were significantly different from the expecte ... | 2003 | 12803642 |
| colony insularity through queen control on worker social motivation in ants. | we investigated the relative contribution of the queen and workers to colony nestmate recognition cues and on colony insularity in the carpenter ant camponotus fellah. workers were either individually isolated, preventing contact with both queen and workers (colonial deprived, cd), kept in queenless groups, allowing only worker-worker interactions (queen deprived, qd) or in queenright (qr) groups. two weeks post-separation qd and qr workers were amicable towards each other but both rejected thei ... | 2003 | 12803913 |
| dominant meat ants affect only their specialist predator in an epigaeic arthropod community. | ants are thought to exert an important influence on the structure of arthropod assemblages through predation and competition. i examined the effect of a dominant ant, iridomyrmex purpureus, on epigaeic arthropod assemblages on rock outcrops using an exclusion experiment. i compared arthropod assemblages on four replicate outcrops allocated to each of the following treatments: i. purpureus present; i. purpureus absent; i. purpureus excluded; and procedural control. nests of i. purpureus were cage ... | 2003 | 12844254 |
| morphological adaptation of the skull for various behaviors in the tree shrews. | skull size and shape were examined among 14 species of the tree shrews (tupaia montana, t. picta, t. splendidula, t. mulleri, t. longipes, t. glis, t. javanica, t. minor, t. gracilis, t. dorsalis, t. tana, dendrogale melanura, d. murina, and ptilocercus lowii). the bones of face were rostro-caudally longer in t. tana and t. dorsalis, contrasting with t. minor and t. gracilis, d. melanura, d. murina and p. lowii which have smaller facial length ratios. the arbo-terrestrial species (t. longipes an ... | 2003 | 12951419 |
| united states department of agriculture-agricultural research service research on veterinary pests. | an overview of ars research in the field of veterinary pests is presented. results of research from the past three years on ticks, fire ants, nuisance flies, mosquitoes, sand flies and black flies, among others, are included. where applicable, significance of research is discussed. | 2003 | 12846334 |
| investigation by solid-phase microextraction and gas chromatography/mass spectrometry of trail pheromones in ants. | the dufour's gland content of workers of two ant species of the genus messor has been analyzed by solid-phase microextraction and gas chromatography with mass spectrometry (gc/ms). the structures of the compounds in the pheromonal mixtures have been determined. in both cases only one intact gland, inserted in a properly dimensioned capillary vial, is sufficient to produce a clean and fully interpretable gc/ms profile. it is worth noting that, for the first time in messor ants, farnesol has been ... | 2003 | 12955735 |
| army ants: an evolutionary bestseller? | army ants are characterized by a complex combination of behavioral and morphological traits. molecular data now indicate that army ant behavior has a unique evolutionary origin and has been conserved for over more than 100 million years. | 2003 | 12956971 |
| coevolution between slave-making ants and their hosts: host specificity and geographical variation. | we explored the impact of a slave-making ant, protomognathus americanus, on two of its hosts, leptothorax longispinosus and l. ambiguus. we showed that, on average, slave-maker colonies conduct raids on 2.7 l. longispinosus and 1.4 l. ambiguus nests in a single year. the more common host, l. longispinosus, survives raiding and colony-founding events in a third of the cases, but the less common host rarely survives attacks from the slave-makers. we compare our results, collected in vermont, to a ... | 2003 | 12969483 |
| formicitylenchus oregonensis n. g., n. sp. (allantonematidae: nematoda), the first tylenchid parasite of ants, with a review of nematodes described from ants. | the first tylenchid parasite of ants, formicitylenchus oregonensis n. g., n. sp., is described from a queen carpenter ant camponotus vicinus mayr in western oregon, usa. the new genus is characterised by the excretory pore anterior to the nerve-ring and rounded tails in the free-living adults, a stylet bearing basal thickenings in the free-living female, a smaller stylet lacking basal thickenings in the male and a short, crenulate leptoderan bursa. the mature parasitic female is light yellow and ... | 2003 | 12975624 |
| determining the foraging range and origin of resurgence after treatment of argentine ant (hymenoptera: formicidae) in urban areas. | the foraging range and distribution of argentine ant, linepithema humile (mayr), colonies in urban areas of southern california extended at least 61 m (200 feet) from feeding stations and structures. ants were fed at 25% sucrose feeding stations containing 0.01% fluorescent brighter (fb28). within 14 d, from 77-90% of the ants sampled next to the feeding stations were positive for fb28. the percentage of ants with fb28 declined gradually to approximately 55% 61 m away from the feeding station. t ... | 2003 | 12852625 |
| the effect of metapleural gland secretion on the growth of a mutualistic bacterium on the cuticle of leaf-cutting ants. | in acromyrmex octospinosus leaf-cutting ants the metapleural glands produce an array of antibiotic compounds that serve as a general defence against unwanted microbes on the cuticle. leaf-cutting ants also grow mutualistic pseudonocardiaceae bacteria on their cuticle that produce antibiotics controlling a microfungal parasite of their fungus gardens. interaction between this bacterium and gland secretion therefore seems unavoidable. we document the typical development of bacterial growth on the ... | 2003 | 14504783 |
| effect of aromatic cedar mulch on argentine ant (hymenoptera: formicidae) foraging activity and nest establishment. | in the laboratory, argentine ant, linepithema humile (mayr), mortality was positively correlated to the length of an aromatic cedar mulch section that had to be crossed before food could be reached. when ants could access food without crossing the mulch, mortality was not correlated to mulch section length. in the field, argentine ants showed a tendency to avoid aromatic cedar mulch as a nesting substrate. in plant beds alongside buildings the number of ant nests (pockets containing brood) found ... | 2003 | 12852626 |
| pathogenicity of bacillus thuringiensis isolated from two species of acromyrmex (hymenoptera, formicidae). | the control of acromyrmex leaf-cutting ants is necessary due to the severe damage they cause to diverse crops. a possibility was to control them using the bacterium bacillus thuringiensis (bt) that characteristically produces insecticidal crystal proteins (icps). the icps have been effective in controlling lepidopterans, dipterans, and coleopterans, but their action against hymenopterans is unknown. this paper describes an attempt to isolate bt from ants of two acromyrmex species, to evaluate it ... | 2003 | 14509852 |
| snapshot memories and landmark guidance in wood ants. | insects are thought to pinpoint a place by using memorized "snapshots," i.e., two-dimensional retinotopic views of the surrounding landmarks recorded when at the place (reviewed in ). insects then reach the place by moving until their current view matches their snapshot. to determine when snapshots are recalled, and how differences between view and snapshot are translated into appropriate movements, we analyzed the approaches of wood ants to a feeding site that was located in the center of an ar ... | 2003 | 13678592 |
| individual variation in the rate of use of tree-hole tools among wild orang-utans: implications for hominin evolution. | primate tool use varies among species, populations, and individuals. individual variation is especially poorly understood. orang-utans in the sumatran swamp forest of suaq balimbing varied widely in rates of tool use to extract honey, ants or termites from tree holes and in the degree to which they specialized on this tree-hole tool use. we tested whether individual variation was best explained by effects of social dominance, habitat differences, or by opportunities for socially learning the ski ... | 2003 | 12604301 |
| self-organized criticality in ant brood tending. | a new stochastic lattice gas model of ant brood tending is formulated to examine the role played by repulsive ant-ant interactions in the even distribution of care among brood members. the deterministic limit of the model is known to be self-organized critical. numerical simulations of the model show that the ant-ant repulsion facilitates an even distribution of brood care in the middle of the brood. this provides a possible explanation for the fact that ants sort their brood so that the younges ... | 2003 | 12634039 |
| when houseguests become parasites: sympatric speciation in ants. | 2003 | 12782793 | |
| fire ants represent an important risk for anaphylaxis among residents of an endemic region. | imported fire ants (ifa) represent a potential anaphylactic risk to ifa-sensitized individuals. | 2003 | 12789229 |
| effects of wolbachia on mtdna variation in two fire ant species. | wolbachia are endosymbiotic bacteria that infect arthropods. as they are maternally transmitted, the spread of wolbachia variants within host populations may affect host mtdna evolution. we sequenced a portion of the mitochondrial cytochrome oxidase i gene from numerous individuals of two wolbachia-infected fire ant species, solenopsis invicta and s. richteri, to determine how these bacteria influence patterns of mtdna variation. as predicted, there was a strong association between wolbachia str ... | 2003 | 12803629 |
| behavioral mechanisms underlie an ant-plant mutualism. | predators can reduce herbivory by consuming herbivores (a consumptive effect) and by altering herbivore behavior, life history, physiology or distribution (non-consumptive effects). the non-consumptive, or trait-mediated, effects of predators on prey may have important functions in the dynamics of communities. in a facultative ant-plant mutualism, we investigated whether these non-consumptive effects influenced the host plants of prey. here, predaceous ants (forelius pruinosus) consume and distu ... | 2003 | 12647103 |
| why does the larval integument of some sawfly species disrupt so easily? the harmful hemolymph hypothesis. | the larvae of several sawfly species belonging to the tenthredinidae (hymenoptera) have such a low mechanical resistance in the integument that slight mechanical damage to the integument is enough to provoke the release of hemolymph at a given spot. we quantified this phenomenon, which we call "easy bleeding", by measuring the pressure needed to pierce dissected sawfly integument. we also investigated the feeding deterrance of ethanolic extracts of the hemolymph by laboratory bioassays using myr ... | 2003 | 12647187 |
| cysticercoids of five species of raillietina fuhrmann, 1920 (cestoda: davaineidae) in ants, pheidole sp., from emu farms in australia. | cysticercoids of five species of raillietina, r. australis (krabbe, 1869) fuhrmann, 1924, r. beveridgei o'callaghan, davies & andrews, 2000, r. chiltoni o'callaghan, davies & andrews, 2000, r. dromaius o'callaghan, davies & andrews, 2000 and r. mitchelli o'callaghan, davies & andrews, 2000, parasitic in the emu dromaius novaehollandiae latham, are described. each species was identified on the basis of the number and size of the rostellar hooks, which correspond to those of adult worms. cysticerc ... | 2003 | 12815212 |
| size-correlated division of labour and spatial distribution of workers in the driver ant, dorylus molestus. | driver ants ( dorylus spp.) show a high degree of worker polymorphism. previous reports suggest that large dorylus workers are specialised for defensive tasks. in this study, we first quantitatively tested whether there is a size-correlated division of defensive labour among workers. second, we determined whether the spatial distribution of workers outside the nest can be predicted based on such size-specific differences in task allocation. we show that the division of defensive behaviour among ... | 2003 | 12835840 |
| [within-colony relatedness asymmetry and social conflicts in ants]. | the haplodiploïd sex-determining system of hymenoptera, whereby males usually develop from unfertilized eggs and females from fertilised eggs, results in relatedness coefficients that are not uniform among colony members. these asymmetries in relatedness are directly affected by the genetic architecture of the colony, which in turn depends on various factors such as queen number or queen mating frequency. relatedness asymmetries induce different fitness returns per unit investment and, as a resu ... | 2003 | 12836218 |
| informational constraints on optimal sex allocation in ants. | workers of the ant formica truncorum specialize in rearing females or males depending on the number of fathers of a colony. these split sex ratios increase inclusive fitness, but it has remained unknown how workers assess the number of patrilines in their colonies and to what extent their reproductive decisions are constrained by lack of information. by analysis of the quantitative variation in cuticular hydrocarbon profiles of workers of multiply mated queens, we show that the heritable compone ... | 2003 | 12837935 |