| brains of ants and elephants. | | 1997 | 9282222 |
| microsatellite loci for pseudomyrmex pallidus (hymenoptera:formicidae). | | 1997 | 9301076 |
| critical role of lipid composition in membrane permeabilization by rabbit neutrophil defensins. | we have examined the interactions of the six known rabbit neutrophil defensin antimicrobial peptides with large unilamellar vesicles (luv) made from various lipid mixtures based on the lipid composition of escherichia coli membranes. we find that the permeabilization of luv made from e. coli whole lipid extracts differs dramatically from that of single-component luv made from palmitoyl-oleoyl-phosphatidylglycerol (popg). specifically, defensins np-1, np-2, np-3a, np-3b, and a natural mixture of ... | 1997 | 9305875 |
| stepping patterns in ants - influence of speed and curvature | the locomotory behaviour of workers of 12 ant species belonging to four different genera (formicinae: cataglyphis, formica, lasius; myrmicinae: myrmica) was studied by filming individuals walking on smoked-glass plates. subsequent multivariate analyses of footfall positions and walking kinematics revealed a set of constant features characterizing ant locomotion. the alternating tripod gait prevails over a wide range of speeds. the temporal rigidity of tripod coordination is paralleled by spatial ... | 1994 | 9317406 |
| stepping patterns in ants - influence of body morphology | the locomotory behaviour of 12 ant species belonging to four different genera (formicinae: cataglyphis, formica, lasius; myrmicinae: myrmica) was studied by filming individuals during walking on smoked-glass plates. subsequent multivariate analyses of walking kinematics and footfall positions showed marked species-specific as well as size-dependent differences in the locomotory behaviour. the geometric properties of the footfall patterns resulting from the alternating tripod gait scale to leg di ... | 1994 | 9317436 |
| stepping patterns in ants - influence of load | stepping pattern geometry and walking kinematics of individual foragers of cataglyphis fortis (formicidae: hymenoptera) were recorded during outward and homeward trips to and from a food source. while returning homewards, the animals were supplied with food items of defined mass (load ratio from 1.3 to 6.4) and volume. under the influence of load, the temporal interleg coordination pattern was maintained (alternating tripod gait), but the spatial tripod pattern was modified. tripod deformation w ... | 1994 | 9317463 |
| middle-scale navigation: the insect case | what is the large-scale spatial representation that insect foragers such as bees and ants form of their wider nest environs? this is the principal question which the following contributions aim to answer. | 1996 | 9317475 |
| visual navigation in insects: coupling of egocentric and geocentric information | social hymenopterans such as bees and ants are central-place foragers; they regularly depart from and return to fixed positions in their environment. in returning to the starting point of their foraging excursion or to any other point, they could resort to two fundamentally different ways of navigation by using either egocentric or geocentric systems of reference. in the first case, they would rely on information continuously collected en route (path integration, dead reckoning), i.e. integrate ... | 1996 | 9317483 |
| insect navigation en route to the goal: multiple strategies for the use of landmarks | there are at least four distinct ways in which familiar landmarks aid an insect on its trips between nest and foraging site. recognising scenes: when bees are displaced unexpectedly from their hive to one of several familiar locations, they are able to head in the direction of home as though they had previously linked an appropriate directional vector to a view of the scene at the release site. biased detours: ants recognise familiar landmarks en route and will correct their path by steering con ... | 1996 | 9317693 |
| questioning paradigms: caste-specific ventilation in harvester ants, messor pergandei and m. julianus (hymenoptera: formicidae) | do developmental constraints in ant colonies limit gas exchange strategies to those displayed by female alates (presumptive queens)? in the xeric harvester ant genus messor, we found that m. pergandei and m. julianus female alates ventilated highly discontinuously, as predicted, but m. julianus workers ventilated less discontinuously and m. pergandei workers (which occur in more xeric habitats) ventilated continuously. we present the salient characteristics of the discontinuous ventilation cycle ... | 1995 | 9318205 |
| optical scaling in conspecific cataglyphis ants | this study examines the effects of body size variation on the optical properties of the compound eyes of visually guided desert ants belonging to the genus cataglyphis. although linear head size may vary by a factor of 2 within conspecific workers and most optical parameters change accordingly, the extent of the visual field remains constant. comparative measurements carried out on workers of three species (c. albicans, c. bicolor and c. fortis) and on reproductive females and males of one speci ... | 1995 | 9319542 |
| age-dependent and task-related morphological changes in the brain and the mushroom bodies of the ant camponotus floridanus | based on a brief description of the general brain morphology of camponotus floridanus, development of the brain is examined in ants of different ages (pupa to 10 months). during this period, brain volume increases by approximately 20 % while the antennal lobes and the mushroom body neuropile show a more substantial growth, almost doubling their volume. in addition to the age-dependent changes, the volume of the mushroom body neuropile also increases as a consequence of behavioural activity assoc ... | 1996 | 9319922 |
| the trap-jaw mechanism in the dacetine ants daceton armigerum and strumigenys sp. | ants of three different subfamilies, among them the tribe dacetini, have evolved very fast snapping mandibles called trap-jaws. the two dacetine genera examined, the large daceton and the small strumigenys, employ the same mechanism for their mandible strike. video analysis reveals that, in strumigenys sp., the strike takes less than 2.5 ms. it is released within 5 ms by contact of trigger hairs on the labrum. the ants employ a catapult mechanism to generate such a fast movement. before the stri ... | 1996 | 9319931 |
| slow inhibition of na+ current in crayfish axons by 2-(1non-8enyl)-5-(1non-8enyl)pyrrolidine (pyr9), a synthetic derivative of an ant venom alkaloid | 2,5-dialkylpyrrolidines present in the venom of ants from the genus monomorium are natural insecticides causing a flaccid paralysis. the mechanism of action of 2-(1non-8enyl)-5-(1non-8enyl)pyrrolidine (pyr9), a synthetic derivative of 2,5-dialkylpyrrolidines, has been investigated in vitro on preparations of the ventral nerve cord of the crayfish procambarus clarkii. our results clearly indicate that pyr9 blocks spike conduction without affecting the resting potential. voltage-clamp experiments ... | 1997 | 9320008 |
| a preliminary analysis of insects of medico-legal importance in curitiba, state of paraná. | a survey of the carrion fauna was made at two sites in curitiba, state of paraná, with the objective of describing the insects associated with carrion and setting up a preliminary data-base for medico-legal purposes in south brazil. vertebrate exclusion experiments were carried out in each season between 1994 and 1995 with a 250 g laboratory-bred rat (rattus norvegicus). five stages of decomposition were identified: fresh, bloated, decaying, dry and adipocere-like. some species showed seasonal a ... | 1997 | 9332590 |
| hierarchical analysis of genetic structure in native fire ant populations: results from three classes of molecular markers. | we describe genetic structure at various scales in native populations of the fire ant solenopsis invicta using two classes of nuclear markers, allozymes and microsatellites, and markers of the mitochondrial genome. strong structure was found at the nest level in both the monogyne (single queen) and polygyne (multiple queen) social forms using allozymes. weak but significant microgeographic structure was detected above the nest level in polygyne populations but not in monogyne populations using b ... | 1997 | 9335601 |
| three opsin-encoding cdnas from the compound eye of manduca sexta. | three distinct opsin-encoding cdnas, designated manop1, manop2 and manop3, were isolated from the retina of the sphingid moth manduca sexta. manop1 codes for a protein with 377 amino acid residues. it is similar in sequence to members of a phylogenetic group of long-wavelength-sensitive arthropod photopigments, most closely resembling the opsins of ants, a praying mantis, a locust and the honeybee. manop2 and manop3 opsins have 377 and 384 residues respectively. they belong to a related group of ... | 1997 | 9343857 |
| self-organizing nest construction in ants: individual worker behaviour and the nest's dynamics | we examine nest construction in the ant leptothorax tuberointerruptus at two levels: (1) the building behaviour of individual workers and (2) the collective properties (temporal and spatial) of the structures they create. we also explore, for the first time explicitly, the linkage between these two levels. leptothorax tuberointerruptus nests occur in flat cavities which provide the roof and the floor of their dwelling places. hence, they construct only a peripheral encircling wall, breached by o ... | 1997 | 9344432 |
| worker reproduction and social hierarchies in leptothorax ants | kin selection theory predicts the existence of potential conflict between queen and workers and among workers concerning the production of males in insect societies with a single, once-mated queen. we investigated the occurrence of reproductive conflict and worker reproduction in both single- and multi-queen colonies of 10 species of the ant genus leptothoraxin contrast to previous observations in related species, workers only infrequently engaged in aggressive interactions and did not lay large ... | 1997 | 9344438 |
| defensive production of quinoline by a phasmid insect (oreophoetes peruana). | adults and nymphs of the peruvian stick insect oreophoetes peruana (order phasmatodea) have a pair of thoracic glands from which they discharge a malodorous fluid when disturbed. the secretion contains a single volatile component, quinoline. quinoline has not been reported previously from an animal source. the compound proved repellent or topically irritant in assays with ants, spiders, cockroaches and frogs. o. peruana nymphs, at molting, do not extricate the shed cuticular lining of the glands ... | 1997 | 9366083 |
| proprioceptors and fast antennal reflexes in the ant odontomachus (formicidae, ponerinae). | in ants, antennal movements support the stimulus perception of olfactory and mechanosensory sensilla, most of which are located on the distal part of the antenna. in addition, sensory hair plates, campaniform sensilla, and janet's organ provide the ant with proprioceptive information about the position, velocity, and acceleration of their antennae. we describe the morphology of these proprioceptors and their afferent neurons with special reference to the trap-jaw ant genus odontomachus. all thes ... | 1997 | 9377635 |
| molecular advances in understanding social insect population structure. | social insects present many phenomena seen in all organisms but in more extreme forms and with larger sample sizes than those observable in most natural populations of vertebrates. microsatellites are proving very much more informative than allozymes for the analysis of population biological problems, and prolifically polymorphic markers are fairly readily developed. in addition, the male-haploid genetic system of many social insects facilitates genetic analysis. the ability to amplify dna from ... | 1997 | 9378143 |
| reactions to less common species of fire ants. | there are four species of fire ants found in the united states in addition to the most common, solenopsis invicta. reactions have been reported from stings of each of these species, but large numbers of insects and adequate amounts of venom for study are very difficult to obtain. | 1997 | 9389299 |
| estimation of postmortem interval based on colony development time for anoplolepsis longipes (hymenoptera: formicidae). | the postmortem interval for a set of human remains discovered inside a metal tool box was estimated using the development time required for a stratiomyid fly (diptera: stratiomyidae), hermetia illucens, in combination with the time required to establish a colony of the ant anoplolepsis longipes (hymenoptera: formicidae) capable of producing alate (winged) reproductives. this analysis resulted in a postmortem interval estimate of 14 + months, with a period of 14-18 months being the most probable ... | 1997 | 9397565 |
| behavioural responses of eurasian treecreepers, certhia familiaris, to competition with ants | competition for a specific resource that is essential for the survival of both the competitors may be intense even between very dissimilar taxa. however, the importance of the effects caused by such interspecific competition has seldom been emphasized. these effects can appear as differences in individual foraging behaviour during the breeding season, which can result in critical variation in fitness. in this study we examined the effects of wood ants (formica rufa group) on the abundance of oth ... | 1997 | 9398381 |
| the effect of past and present group size on responses to prey in the ant formica polyctena först. | we investigated the responses to insect prey (dead houseflies) in 24 "derivative groups" of workers of the ant formica polyctena created by taking sets of 25 workers out of nine larger "initial groups" kept in laboratory without queens and brood during the preceding five months. in the derivative groups the ants ceased to retrieve flies to their nests after a period ranging from few days to several weeks. the duration of that period did not depend on the present size of the derivative group (dec ... | 1997 | 9407700 |
| laboratory observations of nuptial flights of the ant polyrhachis laboriosa. | ethology of polyrhachis laboriosa, an ant species from equatorial africa, is little known. no field observation of a nuptial flight of these ants was ever made. we describe two nuptial flights observed in a laboratory colony of p. laboriosa at a 3 days interval. they both occurred in the morning while the nest was kept in near darkness (less than 2 lux of daylight). flying activity of the alates was suppressed within 1 h by their exposure to daylight of about 140 lux, and within several minutes ... | 1997 | 9407702 |
| insect societies and the molecular biology of social behavior. | this article outlines the rationale for a molecular genetic study of social behavior, and explains why social insects are good models. summaries of research on brain and behavior in two species, honey bees and fire ants, are presented to illustrate the richness of the behavioral phenomena that can be addressed with social insects and to show how they are beginning to be used to study genes that influence social behavior. we conclude by considering the problems and potential of this emerging fiel ... | 1997 | 9423349 |
| two-dimensional mapping of 8-amine-1,3,6-naphthalene trisulfonic acid derivatives of n-linked neutral and sialyloligosaccharides. | we describe a simple and sensitive two-dimensional sugar-mapping technique of 8-amine-1,3,6-naphthalene trisulfonic acid derivatives (ants derivatives) of neutral and sialyloligosaccharides for structure analysis and characterization of n-linked oligosaccharides using picomoles of samples. the method includes: (1) reductive amination with ants of enzymatically released oligosaccharides, (2) simultaneous separation of oligosaccharide derivatives in a fluorophore-assisted carbohydrate electrophore ... | 1998 | 9466794 |
| efficacy of bait distributional strategies to deliver canine rabies vaccines to coyotes in southern texas. | this study sought to develop a baiting strategy to deliver an oral rabies vaccine to free-ranging coyotes (canis latrans) in southern texas. to determine bait longevity, dog foodlard baits were placed (n = 50) on- and off-roads during july 1994 and january 1995. coyote visitation and uptake rates did not differ between on-road and off-road placement of baits. to evaluate bait stations as possible visual cues, baits were placed out both with (n = 50) and without (n = 50) bait stations. a visual c ... | 1998 | 9476222 |
| phylogeny of fungus-growing ants (tribe attini) based on mtdna sequence and morphology. | we examined the phylogenetic relationships among taxa of attine or "fungus-growing" ants (tribe attini) using parsimony analyses of molecular and morphological data. we sequenced a region of mitochondrial dna from 13 taxa of attines and from one closely related outgroup species, wasmannia auropunctata. our study sequence included the 3' end of the cytochrome c oxidase subunit i (co i) locus (183 to 198 total sites; 91 informative sites), an intergenic spacer region of variable size (0 to 152 sit ... | 1998 | 9479692 |
| monogyny and regulation of worker mating in the queenless ant dinoponera quadriceps | the morphologically specialized queen caste has been lost in various ponerine ants, and mated workers ('gamergates') reproduce instead of queens. unlike previous reports in the literature, we found only one gamergate in each colony of dinoponera quadriceps. we documented monogyny by dissecting ovaries and spermathecae in 914 workers from 15 colonies, and by observing mating in the laboratory. in colonies without a gamergate, aggressive interactions among some of the unmated nestmates led to the ... | 1998 | 9480697 |
| trail pheromone of the myrmicine ant aphaenogaster rudis (hymenoptera: formicidae). | | 1998 | 9484710 |
| corneal injury caused by imported fire ants in a child with neurological compromise. | | 1998 | 9503321 |
| patch sampling behaviour and future foraging expectations in argentine ants, linepithema humile | nests of argentine ants, l. humile, were exposed to pairs of foraging patches of varying quality. these patches varied from never having food to having food for 4 h every day. after 15 days, colonies were allowed an added access to a new patch. the new patch, however, never contained food. the sampling behaviour of nests towards the initial patches and the new patch suggested that the nests were using a sampling rule based on maximizing net benefits of finding food minus the cost of sampling. th ... | 1998 | 9514665 |
| parallel implementations of individual-based models in biology: bulletin- and non-bulletin-board approaches. | particle-based models are simulations in which the discrete representation of physical phenomenon involves interacting particles. this paper studies the efficiency of two different methods of implementing these models on a network of unix workstations. two data parallel methods of modeling particles are tested: bulletin-board and non-bulletin-board. in the former method, the programs communicate through a logically shared, associative memory called a bulletin-board. the simulated particles are d ... | 1998 | 9544401 |
| jumper ants don't bite they sting. | | 1998 | 9581344 |
| [the behavioral strategy of ants with a change in the level of food motivation]. | learning of ants was studied in a symmetrical multi-choice maze at different levels of food "social" motivation. a capability was shown of scout ants myrmica rubra for changing rapidly behavioral strategy when the motivation level of a family changed from the low one for the high or vice versa. in the satiated state the ants demonstrated a clear-cut research activity. this activity was associated with high variability and instability of the maze habit. in the "hungry" state movement trajectories ... | 1998 | 9583168 |
| proteolytic enzymes from larvae of the fire ant, solenopsis invicta. isolation and characterization of four serine endopeptidases. | the imported red fire ant (solenopsis invicta) is a problematic pest in the southern united states. the stages of development for these ants are as follows: egg, 1st, 2nd, 3rd, and 4th instar larvae, prepupae, pupae, and adult. the 4th instar larvae plays an important role in the survival of the colony in that it is totally responsible for the digestion of solid foods and the source of nutrients for the queen and adult workers. in our studies we have been successful in purifying and characterizi ... | 1998 | 9603955 |
| analysis of binding and membrane destabilization of phospholipid membranes by surfactant apoprotein b. | to further elucidate the nature of the molecular interactions of surfactant apoprotein b (sp-b) with phospholipid (pl) membranes, we studied the binding of sp-b to pl membranes and the lipid-dependency of its subsequent effects on leakage and fusion of membranes. sp-b binding to membranes was studied by labeling the protein with the fluorophore 7-nitro-2,1,3-benzoxadiazol-4-yl (nbd) and measuring the fluorescence of the labeled protein in the presence of varying amounts of dipalmitoylphosphatidy ... | 1998 | 9630660 |
| bites and stings of the arthropod kind. treating reactions that can range from annoying to menacing. | bites and stings from arthropods are largely inevitable because of the number of offending species and their distribution throughout our environment. wasps, bees, ants, mosquitoes, gnats, chiggers, and fleas are found all across the united states. thus far, africanized honeybees are limited to southwestern states and fire ants to southern states. brown recluse spiders are found most often in the midwest and south central region, but the black widow spider is found in all 48 contiguous states. th ... | 1998 | 9633544 |
| direct homing behaviour in the ant tetramorium caespitum (formicidae, myrmicinae). | direct homing refers to the behaviour whereby an ant with food runs in an almost straight line to the nest. we determined whether non-polarized light acts as a directional cue in the direct homing behaviour of the grass ant, tetramorium caespitum. we carried out tests (1) under a blue sky or in total overcast conditions in the field, and (2) with a view of the sun or with a non-polarized light within a box in the laboratory. the ants' paths were recorded, and then analysed by means of circular a ... | 1998 | 9641989 |
| the synchronization of recruitment-based activities in ants. | a simple model of recruitment-based foraging in ants illustrates the idea that synchronized patterns of activity can endow a colony with the ability to forage more efficiently when a minimal number of active individuals is required to establish and maintain food source exploitation. this model, which can be extended to other activities that involve recruitment, may help explain why bursts of synchronization have been observed in several species of ants. | 1998 | 9648665 |
| successful rush immunotherapy for anaphylaxis to imported fire ants. | | 1998 | 9648718 |
| fusion between retinal rod outer segment membranes and model membranes: a role for photoreceptor peripherin/rds. | peripherin/rds plays an essential role in the maintenance of photoreceptor rod cell disk membrane structure. the purification of this protein to homogeneity [boesze-battaglia, k., et al. (1997) biochemistry 36, 6835-6846] has allowed us to characterize the functional role of peripherin/rds in the maintenance of rod outer segment (ros) membrane fusion processes. utilizing a cell-free fusion assay system, we report that the fusion of r18-labeled ros plasma membrane (r18-pm) with disk membranes or ... | 1998 | 9649331 |
| following the invisible trail: kinematic analysis of mate-tracking in the copepod temora longicornis. | we have analysed the fine-scale kinematics of movement of male and female copepods, temora longicornis, to resolve how these small animals find their mates. location of the trail initially involves rapid random turning and high rates of directional change. males subsequently increase their rate of movement as they follow the trail, and execute a regular pattern of counter turns in both x,z and y,z planes to stay near or within the central axis of the odour field. pursuit behaviour of males is st ... | 1998 | 9652125 |
| a dna probe for the detection of dicrocoelium dendriticum in ants of formica spp. and lasius spp. | repetitive dna sequences present in the genome of dicrocoelium dendriticum were identified by hybridization of genomic dna that had been digested with different restriction enzymes with 32p-labeled genomic d. dendriticum dna. dna fragments containing repetitive sequences were isolated from psti-digested d. dendriticum dna and were subcloned into a plasmid vector. plasmids containing repetitive sequences were identified by colony hybridization. one of these plasmids, designated ddr-iv, was isolat ... | 1998 | 9660142 |
| fatal anaphylaxis due to fire ant stings. | imported fire ants (solenopsis invicta and solenopsis richteri) are the source of a potentially lethal environmental hazard in the southeastern united states. because of their resistance to natural and chemical control, fire ants can overwhelm their environment, causing destruction of land and animals. fire ants can also cause a variety of health problems in humans, ranging from simple stings to anaphylaxis and death. we present a case of a 30-year-old woman who died of anaphylaxis following mul ... | 1998 | 9662108 |
| a novel insect defensin from the ant formica rufa. | by combination of size exclusion and reversed-phase chromatography, we have isolated a novel member of insect defensin-type antimicrobial peptides from the entire bodies of bacteria-challenged formica rufa (hymenoptera, formicidae). the molecular mass of the purified peptide was estimated to be 4120.42 by matrix-assisted laser desorption/ionization-time of flight/mass spectrometry. sequence analysis revealed that this peptide consisted of 40 amino acid residues with six cysteines engaged in the ... | 1998 | 9672756 |
| short wavelength-sensitive opsins from the saharan silver and carpenter ants. | we have previously cloned the opsins coding for the long-wavelength visual pigments from the saharan silver ant and carpenter ant. here we report two new cdna clones isolated from cdna libraries which also code for opsin proteins. these cdnas code for deduced proteins with 369 amino acids which are 91% identical to each other, but only 38% identical to the previously cloned opsins. phyletic comparisons suggest that these opsins are likely the ultraviolet sensitive visual pigments, a conclusion t ... | 1997 | 9706701 |
| analysis of the ribosomal dna sequences of the microsporidia thelohania and vairimorpha of fire ants. | sequences of the 16srrna gene of three microsporidia pathogenic to imported fire ants, solenopsis invicta and solenopsis richteri, were determined and compared to each other and 15 other species of microsporidia. the sequences of 2 thelohania species are nearly identical (99.2% identity), supporting light-microscopic and ultrastructural evidence that thelohania solenopsae and thelohania sp. are closely related but probably not conspecific. sequence comparisons further revealed that vairimorpha s ... | 1998 | 9709016 |
| widespread occurrence of the micro-organism wolbachia in ants. | for more than 20 years, sex allocation in hymenopteran societies has been a major topic in insect sociobiology. a recurring idea was that relatedness asymmetrics arising from their haplodiploid sex determination system would lead to various parent-offspring conflicts over optimal reproduction. a possible weakness of existing theory is that only interests of nuclear genes are properly accounted for. yet, a diversity of maternally transmitted elements manipulate the reproduction of their host in m ... | 1998 | 9721689 |
| the evolution of agriculture in ants | cultivation of fungi for food by fungus-growing ants (attini: formicidae) originated about 50 million years ago. the subsequent evolutionary history of this agricultural symbiosis was inferred from phylogenetic and population-genetic patterns of 553 cultivars isolated from gardens of "primitive" fungus-growing ants. these patterns indicate that fungus-growing ants succeeded at domesticating multiple cultivars, that the ants are capable of switching to novel cultivars, that single ant species far ... | 1998 | 9748164 |
| orientation of polyergus rufescens (hymenoptera, formicidae) during slave-making raids. | we investigated the factors involved in the orientation of raiders of the european amazon ant, polyergus rufescensand how these factors are used by raiders during the different phases of slave-making expeditions. ants at the head of the raiding column did not follow previously deposited chemical trails but oriented by celestial cues. raiders in the middle of the column used celestial factors but were also strongly affected by the recruiting activity of the ants that preceded them. during the ret ... | 1997 | 9794770 |
| evolutionary theories of aging: handle with care. | evolutionary theories are considered by a growing number of gerontologists as providing a basis to understand why aging occurs. | 1998 | 9813435 |
| group and mass recruitment in ant colonies: the influence of contact rates | the influence of contact rates on the efficiency (the ability to exploit a profitable environment) and flexibility (the ability to track down a changing environment) of foraging in ants is studied theoretically in the case where foraging relies on a mixture of group and mass recruitment. it is shown that a combination of efficiency and flexibility can be reached across a range of group sizes if (1) mass recruitment is combined with a low level of group recruitment, and (2) contact rates are weak ... | 1998 | 9822561 |
| metabolism of plant polysaccharides by leucoagaricus gongylophorus, the symbiotic fungus of the leaf-cutting ant atta sexdens l | atta sexdens l. ants feed on the fungus they cultivate on cut leaves inside their nests. the fungus, leucoagaricus gongylophorus, metabolizes plant polysaccharides, such as xylan, starch, pectin, and cellulose, mediating assimilation of these compounds by the ants. this metabolic integration may be an important part of the ant-fungus symbiosis, and it involves primarily xylan and starch, both of which support rapid fungal growth. cellulose seems to be less important for symbiont nutrition, since ... | 1998 | 9835568 |
| interaction of wheat alpha-thionin with large unilamellar vesicles. | the interaction of the wheat antibacterial peptide alpha-thionin with large unilamellar vesicles has been investigated by means of fluorescence spectroscopy. binding of the peptide to the vesicles is followed by the release of vesicle contents, vesicle aggregation, and lipid mixing. vesicle fusion, i.e., mixing of the aqueous contents, was not observed. peptide binding is governed by electrostatic interactions and shows no cooperativity. the amphipatic nature of wheat alpha-thionin seems to dest ... | 1998 | 9865951 |
| hierarchical analysis of variation in the mitochondrial 16s rrna gene among hymenoptera. | nucleotide sequences from a 434-bp region of the 16s rrna gene were analyzed for 65 taxa of hymenoptera (ants, bees, wasps, parasitoid wasps, sawflies) to examine the patterns of variation within the gene fragment and the taxonomic levels for which it shows maximum utility in phylogeny estimation. a hierarchical approach was adopted in the study through comparison of levels of sequence variation among taxa at different taxonomic levels. as previously reported for many holometabolous insects, the ... | 1998 | 9866207 |
| the ponerine ant pachycondyla (=ophthalmopone) berthoudi forel carries loads economically. | the energy cost of running and carrying a load were measured in the termitophagus ponerine ant pachycondyla (=ophthalmopone) berthoudi. this ant species uses the individual foraging method in which there is no cooperation between the foragers in the search for or retrieval of prey items. the foragers also transport workers and brood between the nests of the polydomous colony. pachycondyla berthoudi foragers ran voluntarily in a running tube respirometer at 25 degrees c. some of the foragers ran ... | 1999 | 9882605 |
| structural characterization of recombinant human erythropoietins by fluorophore-assisted carbohydrate electrophoresis. | routine analysis of the carbohydrate moieties of a glycoprotein is critical for ensuring the consistent quality of biopharmaceutical products. fluorophore-assisted carbohydrate electrophoresis (face) is a recently introduced method for the separation, by polyacrylamide gel electrophoresis, of oligosaccharides labeled with 8-amino-naphthalene-1,3,6-trisulphonic acid (ants). in this study, we have evaluated the applicability of the face method to analysis of the carbohydrate moieties of three diff ... | 1999 | 9989653 |
| pathogens and predators of ticks and their potential in biological control. | this review summarizes the literature about pathogens and predators of ticks and their potential use as biocontrol agents published since the beginning of this century. in nature, many bacteria, fungi, spiders, ants, beetles, rodents, birds, and other living things contribute significantly toward limiting tick populations, as do, for instance, the grooming activities of hosts. experiments with the most promising potential tick biocontrol agents--especially fungi of the genera beauveria and metar ... | 1999 | 9990719 |
| mode of colony foundation influences the primary sex ratio in ants. | in ants, young queens can found new colonies independently (without the help of workers) or dependently (with the help of workers). it has been suggested that differences in the mode of colony founding strongly influence queen survival and colony development. this is because independent queens are constrained to produce a worker force rapidly, before they deplete their body reserves and to resist the intense intercolony competition during the founding stage. by contrast, queens that found coloni ... | 1999 | 10049471 |
| mutability of microsatellites developed for the ant camponotus consobrinus. | five highly polymorphic (ga)n microsatellite loci are reported for the formicine ant camponotus consobrinus. the occurrence of many nests with a simple family structure enabled a search for new mutations, 11 of which were found from 3055 informative typings. these mutations were not randomly distributed across loci, 10 of them occurring at the locus ccon70. the spectrum of mutations across alleles at ccon70 was also nonrandom, with all of them occurring in alleles in the upper half of the allele ... | 1999 | 10065542 |
| optimizing force and velocity: mandible muscle fibre attachments in ants | to be able to perform swift and powerful movements, ant mandible closer muscles are composed of two subpopulations of muscle fibres: fast fibres for rapid actions and slow fibres for forceful biting. all these fibres attach to a sturdy and complex apodeme which conveys force into the mandible base. fast muscle fibres attach directly to the apodeme. slow fibres may attach directly or insert at individual thin filament processes of the apodeme which vary in length. comparisons of different ant spe ... | 1999 | 10069969 |
| [the role of periaqueductal gray neurotensin in electroacupuncture analgesia]. | the effect of periaqueductal gray (pag) injection of neurotensin (nt), anti-nt serum (ants), and naloxone (nx) on both the pain threshold and electroacupuncture (ea) analgesia in rat was investigated in this study. the potassium iontophoresis-induced tail-flick was used to measure the pain threshold. nt administration induced an increase in pain threshold and enhanced ea analgesia. injection of ants reduced the pain threshold significantly and diminished the effect of ea analgesia. furthermore, ... | 1997 | 10074278 |
| the mitochondrial adenine nucleotide translocator from dictyostelium discoideum. functional characterization and dna sequencing. | the mitochondrial adenine nucleotide translocator (ant) catalyses the exchange of atp and adp between the mitochondria and the cytosol. we have cloned and sequenced the gene encoding the dictyostelium discoideum ant (ddant) and analysed its transcriptional regulation. the single copy d. discoideum ant gene encodes a protein of 309 amino acid residues with a predicted molecular mass of 33,469 da and a pi of 9.85. these values are comparable to those of ants from mammals, insects and fungi. the lo ... | 1999 | 10092866 |
| pharoah ants & methoprene. | | 1983 | 10259925 |
| environmental hazards of mobile ground spraying with cyanophos and fenthion for quelea control in senegal. | seven roosts of red-billed quelea, quelea quelea, in the senegal river valley and delta were visited during and after aerial or terrestrial treatments with either cyanox (cyanophos 500 g a.i. liter-1, five roosts) or queletox (fenthion 640 g a.i. liter-1, two roosts). the primary goal of the observations was to provide data on environmental effects of cyanophos after mobile ground spraying operations. twenty-six species of vertebrates (birds, reptile, fish) were found dead or debilitated near th ... | 1999 | 10330314 |
| [experimental studies of the capacity of ants for the addition and subtraction of small numbers]. | in the laboratory experiments formica polyctena ants had to transmit the information about the position of a "branch" situated on a long "trunk". each branch ended in an empty trough, save one filled with syrup. the food was placed on different branches with different frequencies; on the preliminary chosen special branches the troughs were filled substantially more frequently than on the others. for example, in 1993 we chose two special branches, nos. 10 and 20, on which the food was placed with ... | 1999 | 10330701 |
| assessing genetic structure with multiple classes of molecular markers: a case study involving the introduced fire ant solenopsis invicta. | we used 30 genetic markers of 6 different classes to describe hierarchical genetic structure in introduced populations of the fire ant solenopsis invicta. these included four classes of presumably neutral nuclear loci (allozymes, codominant random amplified polymorphic dnas (rapds), microsatellites, and dominant rapds), a class comprising two linked protein-coding nuclear loci under selection, and a marker of the mitochondrial dna (mtdna). patterns of structure revealed by f statistics and exact ... | 1999 | 10331278 |
| learning walks and landmark guidance in wood ants (formica rufa) | we have examined a behaviour pattern in wood ants which in some respects resembles and in other respects differs from the learning flights of bees and wasps. wood ants returning to their nest from a newly discovered food source turn back and look at landmarks near to the feeder, but the feeder itself does not attract sustained fixations. the frequency of landmark inspections is highest when the ant is close to the feeder and falls as the ant moves away. in common with learning flights, inspectio ... | 1999 | 10359685 |
| the emergence of the concept of a tool in food-retrieving behavior of the ants formica japonica motschulsky. | we propose a weak definition for the usage of a tool for an ethological study of ants. in particular, we illustrate the usage of a cart in experiments on the transportation of foods by ants as employing a logical structure including a contradiction. the contradiction originates in ruling out the very term 'tool' from the description of the behavior of the animals. focusing on a self-similar structure underlying the description of a contradiction, we observe a particular time-series sequence of a ... | 1999 | 10367976 |
| emerging patterns and food recruitment in ants: an analytical study | a model of food recruitment by social insects accounting for the competition between trails in the presence of an arbitrary number of sources is developed and analysed in detail. both the case of identical environmental characteristics and the case where one source and the corresponding trail are different from the others are considered. different collective responses depending on the environmental conditions, and without change of individual behaviour, are shown to exist, associated with the po ... | 1999 | 10373356 |
| spatio-temporal learning by the ant ectatomma ruidum | we tested, under field and laboratory conditions, whether the neotropical ant ectatomma ruidum roger can learn several associations between temporal and spatial changes in the daily pattern of food availability. honey was shuffled between two or three feeding sites following a fixed daily schedule. foragers learnt to associate particular sites with the specific times at which food was available, individually marked ants being observed on the correct sites at the correct times. some ants anticipa ... | 1999 | 10377271 |
| testing kin selection with sex allocation data in eusocial hymenoptera | sex allocation data in eusocial hymenoptera (ants, bees and wasps) provide an excellent opportunity to assess the effectiveness of kin selection, because queens and workers differ in their relatedness to females and males. the first studies on sex allocation in eusocial hymenoptera compared population sex investment ratios across species. female-biased investment in monogyne (= with single-queen colonies) populations of ants suggested that workers manipulate sex allocation according to their hig ... | 1999 | 10383666 |
| fire ants: a continuing community health threat in south carolina. | imported fire ants are now firmly established in all 46 counties of south carolina. in 1998 there were an estimated 660,000 cases in the state of which approximately 33,000 sought medical treatment at an estimated cost of 2.4 million dollars. residents and visitors are at risk for ifa attacks that may occur indoors as well as outdoors. while ifa sting victims in endemic areas of the state may be less likely to seek medical treatment, patients in recently infested areas seem to be more likely to ... | 1999 | 10389385 |
| the agricultural pathology of ant fungus gardens. | gardens of fungus-growing ants (formicidae: attini) traditionally have been thought to be free of microbial parasites, with the fungal mutualist maintained in nearly pure "monocultures." we conducted extensive isolations of "alien" (nonmutualistic) fungi from ant gardens of a phylogenetically representative collection of attine ants. contrary to the long-standing assumption that gardens are maintained free of microbial pathogens and parasites, they are in fact host to specialized parasites that ... | 1999 | 10393936 |
| morphologic representation of visual and antennal information in the ant brain. | ants in general are primarily olfactory animals, but many species also express visual behaviors. we analyze in 14 species, which range from purely olfactory to predominantly visually behaving ants, how the brains are equipped to control such behavior. we take the size and manifestation of the eyes as an indicator for the prevalence of vision in a given species, and we correlate it with the size of particular brain regions. our morphometric data show that the size of the eyes generally correlates ... | 1999 | 10441753 |
| cytochalasin b inhibits morphogenetic movement and muscle differentiation of activin-treated ectoderm in xenopus. | xenopus ectodermal explants (animal caps) begin to elongate after treatment with the mesoderm inducing factor activin a. this phenomenon mimics the convergent extension of dorsal mesoderm during gastrulation. to analyze the relationship between elongation movement and muscle differentiation, animal caps were treated with colchicine, taxol, cytochalasin b and hydroxyurea (hua)/aphidicolin following activin treatment. cytochalasin b disrupted the organization of actin filaments and inhibited the e ... | 1999 | 10445501 |
| spray aiming in the bombardier beetle: photographic evidence. | bombardier beetles, when physically assaulted, eject a hot quinonoid spray from the tip of the abdomen. photographic evidence is presented demonstrating that the african bombardier beetle, stenaptinus insignis, can aim its spray in virtually any direction. it can target its individual legs, and even the individual segments of its legs. moreover, in aiming at a leg, it takes into account the postural orientation of that leg. the beetle is able even to target sites on its back. it is postulated th ... | 1999 | 10449758 |
| undertaking specialization in the desert leaf-cutter ant acromyrmex versicolor. | we investigated undertaking behaviour in the desert leaf-cutter ant to determine whether colonies show undertaking specialization, how task specialization is regulated and the consequences of specialization on colony performance. task specialization has been hypothesized to be a result of internal physiological or genetic factors that govern worker behaviour. on the other hand, it has been suggested that task specialization could be a result of spatial structuring of workers allowing only a subs ... | 1999 | 10458895 |
| isolation of magnetic nanoparticles from pachycondyla marginata ants | we report on the presence of magnetic iron oxides in the migratory ant pachycondyla marginata. magnetic particles were extracted from different parts of the ant (head, thorax and abdomen) using magnetic precipitation methods. electron spectroscopic images for iron and oxygen were obtained from the extracted particles, and, by using the corresponding electron micrographs, histograms of size distribution were constructed. selected area diffraction patterns were also obtained from the particles, an ... | 1999 | 10482727 |
| [forensic entomology exemplified by a homicide. a combined stain and postmortem time analysis]. | the combined analysis of both ant and blow fly evidence recovered from a corpse, and from the boot of a suspect, suggested that an assumed scenario in a high profile murder case was likely to be true. the ants (lasius fuliginous) were used as classical crime scene stains that linked the suspect to the scene. blow fly maggots (calliphora spec.) helped to determine the post mortem interval (pmi) with the calculated pmi overlapping with the assumed time of the killing. in the trial, the results of ... | 1999 | 10489592 |
| behavioral strategies in ants in changing conditions of food motivation. | learning in ants was studied in a multiple choice symmetrical maze at different levels of social food motivation. myrmica rubra scout ants were found to be able to change their behavioral strategy rapidly when families were suddenly changed from a low level of motivation to a high level and vice versa. in the "sated" state, there was clearly evident investigative activity, which led to high levels of variability and instability in the maze habit. in the "starved" state, there was a rapid minimiz ... | 1999 | 10493538 |
| fire ant attacks on residents in health care facilities: a report of two cases. | imported fire ants now infest more than 310 million acres in the united states and puerto rico. colonies have been found in arizona, california, new mexico, and virginia. available reports suggest that each year, fire ants sting more than 50% of persons in endemic areas, resulting in a variety of medical consequences. | 1999 | 10498558 |
| a new case of jumping behaviour in ants, as part of the foraging strategy. | we demonstrated for the first time in this laboratory study that the tree-dwelling ant polyrhachis laboriosa can jump down beyond any context of escape or predation. when it is necessary to jump to reach an isolated food supply or explore a larger territory, workers of p. laboriosa jump down from a height of 5-100 cm. the characteristics of this active jumping display are described here. during foraging or exploratory conditions, the workers learnt to jump and integrated this behaviour into thei ... | 1999 | 10505238 |
| flower structure and reproductive biology in aspidosperma quebracho-blanco (apocynaceae), a tree pollinated by deceit. | flower structure, attractants, breeding system, and visitors were studied in aspidosperma quebracho-blanco, a south american mass-flowering tree with simple moth-pollinated flowers and without floral reward. flowers are protandrous, having an initial male phase for 2 d. the pendulous and horizontal flower position and protandry prevent self-pollination. although an inconspicuous annular floral nectary is located at the ovary base, nectar is not secreted. nonstructural, extrafloral nectaries have ... | 1999 | 10506468 |
| calibration of vector navigation in desert ants. | desert ants (cataglyphis sp.) monitor their position relative to the nest using a form of dead reckoning [1] [2] [3] known as path integration (pi) [4]. they do this with a sun compass and an odometer to update an accumulator that records their current position [1]. ants can use pi to return to the nest [2] [3]. here, we report that desert ants, like honeybees [5] and hamsters [6], can also use pi to approach a previously visited food source. to navigate to a goal using only pi information, a fo ... | 1999 | 10508615 |
| worker age, size and social status in queenless colonies of the ant leptothorax gredleri. | workers in queenless colonies of the ant leptothorax gredleri form dominance hierarchies by antennation bouts and biting. the frequency of aggressive interactions peaked when the ants became active again after hibernation, a second time in summer, when new workers eclosed from overwintered brood, and a third time when we experimentally removed the queen. high-ranking individuals were more active and had greater ovarian development than their low-ranking nestmates. we investigated what proximatel ... | 1999 | 10512648 |
| 3-methyl-4-phenylpyrrole from the ants anochetus kempfi and anochetus mayri. | the cephalic extracts of the ant anochetus kempfi were found to contain 2,5-dimethyl-3-isoamylpyrazine (1) and 3-methyl-4-phenylpyrrole (2). the structures of these compounds were established from their spectral data and by comparison with synthetic samples. this is the first report of a phenylpyrrole found in an insect and only the third report of a pyrrole from ants. | 1999 | 10514333 |
| anaphylaxis to venom of the pachycondyla species ant. | in the southeastern united states, imported fire ants have caused systemic reactions with a high incidence. on the contrary, in korea pachycondyla species ants (p chinensis and p solitaria), and the family formicidae, which are in the genus pachycondyla and the subfamily ponerinae, have only occasionally caused systemic reactions. | 1999 | 10518836 |
| queen-worker conflict over sexual production and colony maintenance in perennial social insects. | an important idea from kin selection theory as applied to life-history evolution in perennial insect societies suggests that potential conflict exists between the queen and workers over the relative allocation of resources to colony reproduction and colony growth. this prediction assumed a colony with one singly mated queen, sterile workers, and independent colony foundation by dispersing queens. we argue that this prediction is mistaken because queen and workers under these circumstances can on ... | 1999 | 10523488 |
| modality-specific segregation of input to ant mushroom bodies. | the mushroom bodies are central brain neuropils involved in the control of complex behavior. in ants, the mushroom bodies are relatively large compared to those of honey bees, whereas the optic lobes of ants are considerably smaller. the general morphology of ant mushroom bodies is similar to that of honey bees. as in other hymenoptera, the main input region of the mushroom bodies, the calyx, is subdivided into three compartments: the lip, the collar, and the basal ring. in many ant species this ... | 1999 | 10529521 |
| honeybee memory: navigation by associative grouping and recall of visual stimuli. | studies of navigation in bees and ants are beginning to reveal that foraging insects traveling repeatedly to a food source navigate by using a series of visual images of the environment acquired en route (collett, 1996; collett et al., 1993; judd & collett, 1998; wehner et al., 1990, 1996). by comparing the currently viewed scene with the appropriate stored image, the insect is able to ascertain whether or not it is on the correct path and make any necessary corrections. if a bee happens to fora ... | 1999 | 10536097 |
| ants, agriculture and antibiotics. | | 1999 | 10542448 |
| analysis of 8-aminonaphthalene-1,3,6-trisulfonate-derivatized oligosaccharides by capillary electrophoresis-electrospray ionization quadrupole ion trap mass spectrometry. | dextran was partially hydrolyzed with 0.1 mol/l hcl and the hydrolysate was derivatized with 8-aminonaphthalene-1,3,6-trisulfonate (ants) by reductive amination. the derivatized-oligosaccharide mixture was separated by capillary electrophoresis (ce) in a buffer of 1% hac-nh4oh, ph 3.4, and the separated components were detected on-line by electrospray ionization quadrupole ion trap mass spectrometry (esi-qit-ms) in the negative ion mode. a mass accuracy lower than 0.01% could be achieved and as ... | 1999 | 10551355 |
| optical imaging of odor-evoked glomerular activity patterns in the antennal lobes of the ant camponotus rufipes | ants have a well developed olfactory sense, which they need both for the perception of environmental chemicals, and for a highly sophisticated intraspecific communication system based on pheromones. the question arises therefore as to how different odors are coded in the antennal lobe, the first central neuropil to process olfactory information. we measured odor-evoked activity patterns using in vivo neuropil calcium recording in the antennal lobe of the ant camponotus rufipes. we found that (a) ... | 1999 | 10551948 |
| membrane destabilization assay based on potassium release from liposomes. | inorganic ions are highly suitable markers for monitoring release of the inner content of liposomes. in the present study, a potassium (k(+)) selective electrode was used to evaluate the rate of k(+) release from large unilamellar vesicles (luv). the developed method is highly sensitive, reproducible and inexpensive. since the k(+) ion is smaller than other markers conventionally used, the method described is more sensitive than one of the standard methods that uses ants/dpx. in addition, the me ... | 1999 | 10556492 |
| evolutionary theories of aging. 2. the need not to close the debate. | keller and genoud [gerontology 1999;45: 336-338] consider that a previous article of le bourg [gerontology 1998;44:345-348] is an inappropriate criticism of evolutionary theories of aging and offer a refutation of this article. | 1999 | 10559653 |