| trade-offs in group living: transmission and disease resistance in leaf-cutting ants. | sociality can be associated with significant costs due to the increased risk of disease transmission. however, in some organisms the costs may be offset by benefits due to improvements in defences against parasites. to examine this possible trade-off between infection risk and disease resistance, we used acromyrmex leaf-cutting ants and the entomopathogenic fungus metarhizium anisopliae as the model system. ants exposed to the parasite were found to have substantially improved survival when they ... | 2002 | 12350269 |
| 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 |
| bioactive alkaloids of frog skin: combinatorial bioprospecting reveals that pumiliotoxins have an arthropod source. | nearly 500 alkaloids have been detected in skin extracts from frogs of the family dendrobatidae. all seem to have been sequestered unchanged into skin glands from alkaloid-containing arthropods. ants, beetles, and millipedes seem to be the source of decahydroquinolines, certain izidines, coccinellines, and spiropyrrolizidine oximes. but the dietary source for a major group of frog-skin alkaloids, namely the pumiliotoxins (ptxs), alloptxs, and homoptxs, remained a mystery. in hopes of revealing a ... | 2002 | 12381780 |
| solving the freeloaders paradox: genetic associations and frequency-dependent selection in the evolution of cooperation among nonrelatives. | one of the enduring problems in the study of social evolution has been to understand how cooperation can be maintained in the presence of freeloaders, individuals that take advantage of the more cooperative members of groups they are eager to join. the freeloader problem has been particularly troublesome when groups consist of nonrelatives, and no inclusive fitness benefits accrue to individuals that contribute more heavily to communal activities. these theoretical difficulties, however, are not ... | 2002 | 12381790 |
| comparative study of satellite dna in ants of the messor genus. | the satellite dna of ants messor barbarus and messor bouvieri is analysed. the results are compared with the satellite dna data from messor structor previously reported and with new data obtained from the genome of geographically distinct m. structor population, which have shown that this satellite dna is highly conserved within the species. the satellite dna is organized as tandemly repeated 79 bp monomers in all species. the sampled sequences of the three species show a high similarity and all ... | 2002 | 12384292 |
| the evolution of fungus-growing termites and their mutualistic fungal symbionts. | we have estimated phylogenies of fungus-growing termites and their associated mutualistic fungi of the genus termitomyces using bayesian analyses of dna sequences. our study shows that the symbiosis has a single african origin and that secondary domestication of other fungi or reversal of mutualistic fungi to a free-living state has not occurred. host switching has been frequent, especially at the lower taxonomic levels, and nests of single termite species can have different symbionts. data are ... | 2002 | 12386341 |
| tetraponera ants have gut symbionts related to nitrogen-fixing root-nodule bacteria. | some tetraponera ants (formicidae, pseudomyrmecinae) subsist almost entirely on amino acid deficient honeydew secretions of pseudococcids and harbour a dense aggregation of bacterial symbionts in a unique pouch-shaped organ at the junction of the midgut and the intestine. the organ is surrounded by a network of intruding tracheae and malpighian tubules, suggesting that these bacteria are involved in the oxidative recycling of nitrogen-rich metabolic waste. we have examined the ultrastructure of ... | 2002 | 12396501 |
| 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 |
| conservation of (ttagg)(n) telomeric sequences among ants (hymenoptera, formicidae). | to determine the telomere sequence in tapinoma nigerrimum, we carried out in situ hybridization using ttaggg and ttagg repeat polymerase chain reaction (pcr)-generated probes. no hybridization signals were found when ttaggg was used as a probe. however, strong signals were observed at the end of the chromosomes with the ttagg probe. southern blot analysis carried out on genomic dna using ttagg as a probe showed a strong hybridization signal even under highly stringent conditions. similar results ... | 2002 | 12407216 |
| chemical mimicry: male ants disguised by the queen's bouquet. | | 2002 | 12410300 |
| 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 |
| assessing state-wide biodiversity in the florida gap analysis project. | the florida gap (fl-gap) project provides an assessment of the degree to which native animal species and natural communities are or are not represented in existing conservation lands. those species and communities not adequately represented in areas being managed for native species constitute 'gaps' in the existing network of conservation lands. the united states geological survey gap analysis program is a national effort and so, eventually, all 50 states will have completed it. the objective of ... | 2002 | 12418159 |
| intraspecific variation of cuticular hydrocarbon composition in formica japonica motschoulsky (hymenoptera: formicidae). | cuticular hydrocarbons and morphological features were compared among 80 formica japonica colonies collected in japan. although a few morphological differences were found in workers among the colonies, four different types of cuticular hydrocarbon composition were observed. this was supported by a principal component analysis. we further compared the cuticular hydrocarbons among a total of approximately 400 f. japonica colonies, and categorized the hydrocarbon components into four types based on ... | 2002 | 12426478 |
| ecophysiology and nutritional niche of the bilby (macrotis lagotis), an omnivorous marsupial from inland australia: a review. | the bilby (macrotis lagotis) is a small omnivorous marsupial that was once widespread but is now restricted to the most arid margins of its former range. it feeds on a mixture of invertebrates (mainly ants and termites) and plant material (mainly seeds and bulbs), most of which is below ground. measurements of the energy and water requirements of free-living bilbies and of the maintenance nitrogen requirements of captive animals provided the basis for an explanation for its continued survival in ... | 2002 | 12443940 |
| plasticity in queen number and social structure in the invasive argentine ant (linepithema humile). | in many polygynous social insect societies, ecological factors such as habitat saturation promote high queen numbers by increasing the cost of solitary breeding. if polygyny is associated with constrained environments, queen number in colonies of invasive social insects should increase as saturation of their new habitat increases. here i describe the variation in queen number, nestmate relatedness, and nest size along a gradient of time since colonization in an invading population of argentine a ... | 2002 | 12449488 |
| molecular evidence for the origin of workerless social parasites in the ant genus pogonomyrmex. | speciation of two social parasites from their respective hosts is tested using a molecular phylogeny. alignment of 711 dna base pairs of mitochondrial cytochrome b gene was used to assess phylogenetic relationships of inquiline species to their hosts and to other members of the genus. we show that the inquiline social parasites of the north american seed harvester ants are monophyletic, descending from one of the known hosts (pogonomyrmex barbatus) in the recent past and shifting hosts in a patt ... | 2002 | 12449489 |
| response of ants to a deterrent factor(s) produced by the symbiotic bacteria of entomopathogenic nematodes. | the production of an ant-deterrent factor(s) (adf) by xenorhabdus nematophila and photorhabdus luminescens, the symbiotic bacteria of the nematodes steinernema carpocapsae and heterorhabditis bacteriophora, respectively, was examined. in addition to an in vivo assay in which bacteria were tested for their ability to produce adf within insect cadavers (m.e. baur, h. k. kaya, and d. r. strong, biol. control 12:231-236, 1998), an in vitro microtiter dish assay was developed to monitor adf activity ... | 2002 | 12450845 |
| 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 |
| ant-dipping among the chimpanzees of bossou, guinea, and some comparisons with other sites. | we present a detailed study of ant-dipping among the wild chimpanzees (pan troglodytes verus) of bossou, in southeastern guinea, west africa. observations suggest a strong influence of prey (dorylusspp.) characteristics, including aggressiveness and/or gregariousness, on tool length and technique employed by the chimpanzees. bossou chimpanzees exhibit two ant-dipping techniques: 1) direct mouthing, and 2) pull-through. in addition, they were observed dipping for several species of dorylus ants, ... | 2002 | 12454957 |
| first fossil record of nematode parasitism of ants; a 40 million year tale. | a mermithid nematode emerging from a male ant, prenolepis henschei mayr, in baltic amber is the first fossil record demonstrating nematode parasitism of ants. this parasite, described as heydeniusformicinus sp. n., is compared to extant mermithid parasites of ants, especially allomermis myrmecophila baylis 1921. the present fossil, together with earlier reports of braconid and mite parasitism of ants in baltic amber, indicates that several diverse groups had already evolved parasitic association ... | 2002 | 12458829 |
| molecular phylogenetic evidence for multiple gains or losses of ant mutualism within the aphid genus chaitophorus. | mutualism with ants is suspected to be a highly labile trait within homopteran evolution. we used molecular phylogenetic evidence to test whether the mutualism has multiple origins within a single aphid genus. we constructed a molecular phylogeny of 15 chaitophorus koch (hemiptera: aphidoidea) species, using mitochondrial cytochrome oxidase i and ii sequences. ant tending evolved, or was lost, at least five times during chaitophorus evolution. parametric bootstrapping rejected the hypothesis of ... | 2003 | 12470935 |
| cloning and sequencing of wsp encoding gene fragments reveals a diversity of co-infecting wolbachia strains in acromyrmex leafcutter ants. | by sequencing part of the wsp gene of a series of clones, we detected an unusually high diversity of nine wolbachia strains in queens of three species of leafcutter ants. up to four strains co-occurred in a single ant. most strains occurred in two clusters (inva and invb), but the social parasite acromyrmex insinuator hosted two additional infections. the multiple wolbachia strains may influence the expression of reproductive conflicts in leafcutter ants, but the expected turnover of infections ... | 2003 | 12470942 |
| the occurrence of amphibians in bromeliads from a southeastern brazilian restinga habitat, with special reference to aparasphenodon brunoi (anura, hylidae). | five species of anuran amphibians, all belonging to the family hylidae, were collected at praia das neves, municipality of president kennedy, southeastern brazil. the species were represented by four genera: scinax, hyla, aparasphenodon, and trachycephalus. four species (a. brunoi, hyla albomarginata, scinax altera, and s. cuspidatus) were found during the dry season (august 1999), and two (a. brunoi and trachycephalus nigromaculatus) in the rainy season (february 2000). aparasphenodon brunoi wa ... | 2002 | 12489399 |
| natural enemies of the gall-maker eugeniamyia dispar (diptera, cecidomyiidae): predatory ants and parasitoids. | natural enemies of the gall maker eugeniamyia dispar (diptera: cecidomyiidae) were studied on the urban area of porto alegre, rs, brazil from october 1993 to march 1996. galls and associated arthropods were followed weekly in the field on individual host plants (eugenia uniflora, myrtaceae) and also in the laboratory. three species of ants attacked the galls, the most common being pseudomyrmex sp. a proportion of galls was parasitised by rileya sp. (eurytomidae). the adults of this solitary ecto ... | 2002 | 12489400 |
| the terrestrial reptile fauna of the abrolhos archipelago: species list and ecological aspects. | we have studied the terrestrial reptile fauna of the abrolhos archipelago (a group of five islands located ca. 70 km off the southern coast of the state of bahia, brazil) and analyze here some of its ecological aspects such as diet, thermal ecology, activity, and some reproductive parameters. three lizards comprise the archipelago's terrestrial reptile fauna: tropidurus torquatus (tropiduridae), mabuya agilis (scincidae), and hemidactylus mabouia (gekkonidae). the first two are diurnal and the l ... | 2002 | 12489402 |
| protection of vochysia elliptica (vochysiaceae) by a nectar-thieving ant. | vochysia elliptica (vochysiaceae) is a shrubby plant, which does not have efns. camponotus ants thieve nectar, and can decrease plant fitness by making flowers less attractive to pollinators. however, ants remove herbivores, which can be beneficial. results show that plants from which ants were excluded had lower rates of termite (simulated herbivore) removal than did plants visited by ants. plants accessible to ants showed higher rates of termite removal in the base of leaves and in the inflore ... | 2002 | 12489409 |
| neural mechanisms in insect navigation: polarization compass and odometer. | insect navigation relies on path integration, a procedure by which information about compass bearings pursued and distances travelled are combined to calculate position. three neural levels of the polarization compass, which uses the polarization of skylight as a reference, have been analyzed in orthopteran insects. a group of dorsally directed, highly specialized ommatidia serve as polarization sensors. polarization-opponent neurons in the optic lobe condition the polarization signal by removin ... | 2002 | 12490263 |
| information flow, opinion polling and collective intelligence in house-hunting social insects. | the sharing and collective processing of information by certain insect societies is one of the reasons that they warrant the superlative epithet 'super-organisms' (franks 1989, am. sci. 77, 138-145). we describe a detailed experimental and mathematical analysis of information exchange and decision-making in, arguably, the most difficult collective choices that social insects face: namely, house hunting by complete societies. the key issue is how can a complete colony select the single best nest- ... | 2002 | 12495514 |
| the influence of beacon-aiming on the routes of wood ants. | many insects have an innate propensity to approach conspicuous objects. we explore how such beacon aiming determines the shape of a wood ant's habitual route. we find that a single large black cylinder within an arena biases the route taken by ants as they run from a start position at one end of the arena to reach a feeder at the other. ants learn a stable route with the first segment of their trajectory aimed at the cylinder, which becomes an intermediate goal on the way to the feeder. when in ... | 2003 | 12502774 |
| simple, filter-based pcr detection of thelohania solenopsae (microspora) in fire ants (solenopsis invicta). | thelohania solenopsae is a microsporidian parasite that may serve as a biological control agent for the red imported fire ant, solenopsis invicta. a rapid, filter-based pcr amplification method detecting a portion of the small-subunit ribosomal rna gene was developed to facilitate field studies detecting the parasite in fire ants. processing ant homogenates with a commercially available membrane-based system, fta classic card technology, compared favorably with traditional dna extraction and pcr ... | 2002 | 12503678 |
| [the attraction of silk: base of group cohesion and collective behavior in social spiders]. | social spiders differ from social insects by the production and the use of silk to build irregular webs. this silk prevents dispersion of the individuals and ensures the group cohesion during swarming and collective displacements, playing a part similar to tracks of pheromones in ants. a social spider anelosimus eximius is attracted by conspecific silk and does not show any discrimination relative to its origin, excluding any group closure. the quantity of silk and the state of satiety of the in ... | 2002 | 12506728 |
| detection of thelohania solenopsae (microsporidia: thelohaniidae) in solenopsis invicta (hymenoptera: formicidae) by multiplex pcr. | oligonucleotide primer pairs were designed to unique areas of the small subunit (16s) rrna gene of thelohania solenopsae and a region of the gp-9 gene of solenopsis invicta. multiplex pcr resulted in sensitive and specific detection of t. solenopsae infection of s. invicta. the t. solenopsae-specific primer pair only amplified dna from t. solenopsae and t. solenopsae-infected s. invicta. this primer pair did not produce any amplification products from dna preparations from uninfected s. invicta, ... | 2002 | 12507489 |
| ant allergy in benha district qualyobia governorate, egypt. | individuals from the suburb of benha city and some adjacent villages were presented with various degrees of skin allergy. in addition, chiildren who spend the night (sleep) on the floor suffered generalized lymphadenopathy, with or without fever. the patients were successfully treated with carbolic acid (1:25). besides, oral anti-histamine (h1) and systemic antibiotics were indicated in the complicated cases. in the concrete houses of the patients, a huge number of the large ants (mainly catagli ... | 2002 | 12512822 |
| indolizidine and quinolizidine alkaloids. | this review covers the isolation, structure determination, synthesis and biological activity of indolizidine and quinolizidine alkaloids from microbial, plant and animal sources. included in the review are slaframine; hydroxylated indolizidines and their analogues; alkaloids from ants and amphibians; metabolites of the genera prosopis, streptomyces and nuphar and the lythraceae; phenanthroindolizidines and related alkaloids; lupin alkaloids; and alkaloids from sponges. tunicates and coccinellid ... | 2002 | 12521266 |
| food experience on the predatory behavior of the ant myrmica rubra towards a specialist moth, acrolepiopsis assectella. | entomophagous insects are often repelled by the secondary compounds of the plants eaten by their prey. these compounds, therefore, take on a defensive role for the phytophagous species that sequester them. given that numerous entomophagous species are capable of learning, the effects on the foraging behavior of a repeated experience were investigated in the predatory ant myrmica rubra. the sulfur amino acids methyl-cysteine sulfoxide (mcso) and propyl-cysteine sulfoxide (pcso) produced by allium ... | 2002 | 12523570 |
| ancient tripartite coevolution in the attine ant-microbe symbiosis. | the symbiosis between fungus-growing ants and the fungi they cultivate for food has been shaped by 50 million years of coevolution. phylogenetic analyses indicate that this long coevolutionary history includes a third symbiont lineage: specialized microfungal parasites of the ants' fungus gardens. at ancient levels, the phylogenies of the three symbionts are perfectly congruent, revealing that the ant-microbe symbiosis is the product of tripartite coevolution between the farming ants, their cult ... | 2003 | 12532015 |
| tooth hardness increases with zinc-content in mandibles of young adult leaf-cutter ants. | a wide variety of arthropods and members of other phyla have elevated concentrations of zn, mn, other heavy metals and halogens in their jaws, leg claws, and other "tools" for interacting with the environment. while measured zn concentrations reach 25% of dry mass in scorpion stings, concentrations are often lower than this and the enriched structures are not heavily biomineralized like vertebrate teeth and the radula of mollusks. for this reason, the degree to which the inorganic components of ... | 2002 | 12536282 |
| developmental rates and host specificity for pseudacteon parasitoids (diptera: phoridae) of fire ants (hymenoptera: formicidae) in argentina. | this study extends our comparative knowledge of pseudacteon interactions with solenopsis fire ant workers. reported in this work are development times for seven argentinean parasitoid species reared on two hosts, solenopsis richteri forel and solenopsis invicta buren, under laboratory temperature regimes comparable with those of the climatic zones occupied by these host species. developmental times spanned 31-66 d across phorid species, and in general did not differ between genders or host speci ... | 2002 | 12539825 |
| preference of food particle size among several urban ant species. | appropriate particle size may be a critical characteristic for effective granular ant baits. we examined the particle size preference of six species of pest ants to an anchovy-based bait. we also examined head capsule widths of argentine ants, linepithema humile (mayr) (mean = 0.54 mm), california harvester ants, pogonomyrmex californicus (buckley) (mean = 1.63 mm), red imported fire ants, solenopsis invicta buren (mean = 0.9 mm), and southern fire ants, solenopsis xyloni mccook (mean = 0.76 mm) ... | 2002 | 12539835 |
| homing in pelagic birds: a pilot experiment with white-chinned petrels released in the open sea. | during the breeding period white-chinned petrels (procellaria aequinoctialis) repeatedly perform long foraging trips in the open ocean from their breeding island, and are able to home with an astonishing precision. the orientation mechanisms involved are not yet known. by analogy with those used by desert ants moving in a similarly "featureless" environment, one can hypothesise that petrels may home using path-integration. we displaced 11 white-chinned petrels 725-785km from their burrows to the ... | 2003 | 12543487 |
| tracheal respiration in insects visualized with synchrotron x-ray imaging. | insects are known to exchange respiratory gases in their system of tracheal tubes by using either diffusion or changes in internal pressure that are produced through body motion or hemolymph circulation. however, the inability to see inside living insects has limited our understanding of their respiration mechanisms. we used a synchrotron beam to obtain x-ray videos of living, breathing insects. beetles, crickets, and ants exhibited rapid cycles of tracheal compression and expansion in the head ... | 2003 | 12543973 |
| the swarming and mating behaviour of anopheles gambiae s.s. (diptera: culicidae) from são tomé island. | the swarming and mating behaviours of the forest cytoform of anopheles gambiae s.s. were investigated on 194 evenings and 14 mornings between april 1997 and november 1999 in a peri-urban area of the island of são tomé, west africa. males swarmed 2-3 m above markers of horizontal contrast such as those formed between grass areas and footpaths, or bushes. evening swarms started 2 min before sunset in sheltered sites and a minute or two later in exposed ones. it took approximately 5 mins from the a ... | 2002 | 12546454 |
| do familiar landmarks reset the global path integration system of desert ants? | it is often suggested that animals may link landmark memories to a global coordinate system provided by path integration, thereby obtaining a map-like representation of familiar terrain. in an attempt to discover if desert ants form such associations we have performed experiments that test whether desert ants recall a long-term memory of a global path integration vector on arriving at a familiar food site. ants from three nests were trained along l-shaped routes to a feeder. each route was entir ... | 2003 | 12547942 |
| phylogeny of eusocial lasioglossum reveals multiple losses of eusociality within a primitively eusocial clade of bees (hymenoptera: halictidae). | we performed a phylogenetic analysis of the species, species groups, and subgenera within the predominantly eusocial lineage of lasioglossum (the hemihalictus series) based on three protein coding genes: mitochondrial cytochrome oxidase i, nuclear elongation factor 1alpha and long-wavelength rhodopsin. the entire data set consisted of 3421 aligned nucleotide sites, 854 of which were parsimony informative. analyses by equal weights parsimony, maximum likelihood, and bayesian methods yielded good ... | 2003 | 12554437 |
| intracellular symbionts of sharpshooters (insecta: hemiptera: cicadellinae) form a distinct clade with a small genome. | the leafhoppers (insecta: hemiptera: cicadellidae) are the most species-rich group of invertebrates in which intracellular symbionts are usual. here we present the first molecular characterization of bacteriome-associates in the leafhoppers, with focus on the subfamily cicadellinae (sharpshooters). phylogenetic analyses of 16s rdna sequences from intracellular symbionts residing in the bacteriomes of five host species indicate that these symbionts form a well-defined clade within the gamma-3 pro ... | 2003 | 12558594 |
| 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 |
| stress grows wings: environmental induction of winged dispersal males in cardiocondyla ants. | dispersal is advantageous, but, at the same time, it implies high costs and risks. due to these counteracting selection pressures, many species evolved dispersal polymorphisms, which, in ants, are typically restricted to the female sex (queens). male polymorphism is presently only known from a few genera, such as cardiocondyla, in which winged dispersing males coexist with wingless fighter males that mate exclusively inside their maternal nests. we studied the developmental mechanisms underlying ... | 2003 | 12573217 |
| carbon and nitrogen contents of food bodies in three myrmecophytic species of macaranga: implications for antiherbivore defense mechanisms. | in macaranga myrmecophytes, differences in the production of the food bodies (fbs), on which symbiont ants feed, may relate to the intensity of antiherbivore defense by the ants. interspecific comparisons among macaranga species on such a mutualistic cost give important information on their strategies and evolution of antiherbivore defense. in this study, the carbon and nitrogen contents of fbs as well as the production rate of fbs were measured in three macaranga species, m. winkleri, m. trachy ... | 2002 | 12579367 |
| self-organized lane formation and optimized traffic flow in army ants. | we show how the movement rules of individual ants on trails can lead to a collective choice of direction and the formation of distinct traffic lanes that minimize congestion. we develop and evaluate the results of a new model with a quantitative study of the behaviour of the army ant eciton burchelli. colonies of this species have up to 200 000 foragers and transport more than 3000 prey items per hour over raiding columns that exceed 100 m. it is an ideal species in which to test the predictions ... | 2003 | 12590751 |
| 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 |
| microscale analysis of mucin-type o-glycans by a coordinated fluorophore-assisted carbohydrate electrophoresis and mass spectrometry approach. | the total glycan moiety was released in a single step from native glycoproteins by a nonreductive beta-elimination procedure. the generated oligosaccharides were further derivatized either with the hydrophobic fluorophore 2-aminoacridone (amac) or the charged 8-aminonaphthalene-1,3,6-trisulfonic acid (ants) fluorophore, and the resulting fluorescent derivatives were separated according to their hydrodynamic size or charge with high-resolution gel electrophoresis. both n- and o-glycans released b ... | 2003 | 12601728 |
| 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 |
| sociobiology: worker nepotism among polygynous ants. | | 2003 | 12606988 |
| mechanism of ph-triggered collapse of phosphatidylethanolamine liposomes stabilized by an ortho ester polyethyleneglycol lipid. | the mechanism of ph-triggered destabilization of liposomes composed of a polyethyleneglycol-orthoester-distearoylglycerol lipid (pod) and phosphatidyl ethanolamine (pe) has been studied using an ants/dpx leakage and a lipid-mixing assay. we developed a kinetic model that relates pod hydrolysis to liposome collapse. this minimum-surface-shielding model describes the kinetics of the ph-triggered release of pod/pe liposomes. in the model, when acid-catalyzed hydrolysis lowers the mole percentage of ... | 2003 | 12609880 |
| 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 |
| 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 |
| influence of the hypogaeic army ant dorylus (dichthadia) laevigatus on tropical arthropod communities. | the majority of army ant species forage hypogaeically. due to the difficulties in observing these ants, their potential influence on hypogaeic and epigaeic arthropod communities has not yet been investigated. as the first hypogaeically foraging army ant studied in detail, we attracted dorylus laevigatus to areas monitored for their arthropod diversity. here, for the first time, the same sites were sampled before and after an army ant raid. furthermore, interactions between d. laevigatus and the ... | 2003 | 12647114 |
| species richness and regional distribution of myrmecophilous beetles. | four major hypotheses have been put forward to explain local species richness of commensal or parasitic species. the resource distribution hypothesis predicts that regionally widespread host species are able to support higher local species richness of commensals or parasites. on the other hand, the resource size hypothesis predicts that larger hosts can support more species than smaller hosts, and comparably, the resource abundance hypothesis predicts that hosts that offer more resources are abl ... | 2003 | 12647132 |
| effects of formica ants on soil fauna-results from a short-term exclusion and a long-term natural experiment. | wood ants (formica spp.) were hypothesised to affect the composition and greatly reduce the abundance of large-sized soil fauna by predation. this was tested in two ways. firstly, a 4-year-long experimental study was carried out in a mixed forest. five ant-free 1.3-m(2) plots were created by fenced exclosures within an ant territory. five nearby plots had fences with entrances for the ants. in addition, five non-fenced control plots were selected. soil fauna (e.g. coleoptera, diptera larvae, col ... | 2003 | 12647151 |
| catalpa bignonioides alters extrafloral nectar production after herbivory and attracts ant bodyguards. | inducible anti-herbivore defenses are found within many plant taxa, but there are fewer examples of inducible indirect defenses that incorporate the third trophic level. this study links caterpillar foraging, herbivore-induced changes in extrafloral nectar production, and the attraction of ants to vulnerable leaves and plants. catalpa bignonioides walter (bignoniaceae) uses extrafloral nectar to attract ant (forelius pruinosus(roger)) bodyguards in response to ceratomia catalpae (boisduval)(lepi ... | 2003 | 12647162 |
| 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 |
| 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 |
| comparative survey of abdominal gland secretions of the ant subfamily ponerinae. | the chemical contents of three abdominal glands were investigated in representative species of the ponerine ants. the dufour glands of 14 species show a wide variety of contents. in mystrium camillae and proceratium itoi, no volatile substances were found in either the dufour or venom glands. in ectatomma sp., diacamma ceylonense, diacamma indicum, pachycondyla obscuricornis, and pachycondyla striata, volatile chemicals were found in the venom glands as well as in the dufour glands. platythyrea ... | 2003 | 12647856 |
| landmark memories are more robust when acquired at the nest site than en route: experiments in desert ants. | foraging desert ants, cataglyphis fortis, encounter different sequences of visual landmarks while navigating by path integration. this paper explores the question whether the storage of landmark information depends on the context in which the landmarks are learned during an ant's foraging journey. two experimental set-ups were designed in which the ants experienced an artificial landmark panorama that was placed either around the nest entrance (nest marks) or along the vector route leading strai ... | 2003 | 12649754 |
| effects of contaminants on bait acceptance by solenopsis invicta (hymenoptera: formicidae). | three commonly used fire ant baits, amdro (0.73% hydramethylnon [ai]), ascend (0.011% abamectins [ai]), and maxforce (1.0% hydramethylnon [ai]), were exposed to potential, volatile contaminants. the contaminants included the insecticides orthene fire ant killer (75.0% acephate [ai] ), cyren (44.6% chlorpyrifos [ai]), and tempo 2 (24.3% cyfluthrin [ai]); cigarette smoke; gasoline (unleaded, 89 octane); and fertilizer (10-10-10). fire ant baits previously exposed for 48 h to these contaminants wer ... | 2003 | 12650350 |
| efficacy of bifenthrin treatment zones against red imported fire ant. | exclusion of ants, particularly red imported fire ant, solenopsis invicta (buren), from homes, nursing facilities, hospitals, and electrical housings is an important strategy in urban and rural pest control. we conducted a laboratory bioassay to determine the repellency of granular bifenthrin (talstar: rate 2.087 kg of formulated product/92.88 m2 or 4.6 lb formulated product/1000 feet2 or 4.2 g active ingredient/92.88 m2) to s. invicta foragers. in the field, we compared the efficacy of three wi ... | 2003 | 12650351 |
| molecular evolutionary analyses of mariners and other transposable elements in fire ants (hymenoptera: formicidae). | screens of a library of genomic dna made during a recent study of the fire ant solenopsis invicta revealed the presence of three distinct types of transposable elements (tes). two of the recovered sequences showed a high similarity to long-terminal repeat (ltr) retrotransposons, while the third showed a high homology to mariner elements. to investigate the distribution and relationships of mariners in related ants, we pcr-amplified these elements from additional solenopsis species. phylogenetic ... | 2003 | 12653937 |
| an adaptive ant colony system algorithm for continuous-space optimization problems. | ant colony algorithms comprise a novel category of evolutionary computation methods for optimization problems, especially for sequencing-type combinatorial optimization problems. an adaptive ant colony algorithm is proposed in this paper to tackle continuous-space optimization problems, using a new objective-function-based heuristic pheromone assignment approach for pheromone update to filtrate solution candidates. global optimal solutions can be reached more rapidly by self-adjusting the path s ... | 2003 | 12656341 |
| robots, crickets and ants: models of neural control of chemotaxis and phonotaxis. | neural control in animals can be investigated using robot models. two simple behaviours are focused on: pheromone trail following in ants and sound source localization in crickets. our models address the real sensorimotor constraints and physiological underpinnings of these behaviours. using alcohol gas sensors on a robot it is shown that a simple neural architecture can reproduce a range of trail-following behaviours that qualitatively resemble the results reported for ants. building a more det ... | 1998 | 12662763 |
| local vectors in desert ants: context-dependent landmark learning during outbound and homebound runs. | desert ants, cataglyphis fortis, associate nestward-directed vector memories (local vectors) with the sight of landmarks along a familiar route. this view-based navigational strategy works in parallel to the self-centred path integration system. in the present study we ask at what temporal stage during a foraging journey does the ant acquire nestward-directed local vector information from feeder-associated landmarks: during its outbound run to a feeding site or during its homebound run to the ne ... | 2003 | 12664094 |
| effect of thelohania solenopsae (microsporida: thelohaniidae) on weight and reproductive status of polygynous red imported fire ant, solenopsis invicta (hymenoptera: formicidae), alates. | | 2003 | 12676557 |
| molecular phylogeny and evolutionary biology of acrodipsas (lepidoptera: lycaenidae). | most butterflies in the family lycaenidae associate with ants but fewer than 3% are myrmecophagous. larvae of the australian endemic butterfly genus acrodipsas parasitise the nests of ants from two subfamilies and, thus, constitute an interesting and uncommon myrmecophagous radiation within the lepidoptera. phylogenetic relationships among acrodipsas species were inferred from fragments of mitochondrial cytochrome oxidase subunits i and ii totalling 1155 bp using maximum parsimony and a neighbou ... | 2003 | 12679074 |
| high levels of multiple wolbachia infection and recombination in the ant formica exsecta. | wolbachia bacteria are intracellular symbionts of many arthropod species. their spread through host populations is promoted by drastic alterations imposed on their hosts' reproductive physiology. in the present study, we analyzed the association between wolbachia strains and host mitochondrial haplotypes in a swiss population of the ant formica exsecta. in this species, female dispersal is extremely limited and the mitochondrial haplotypes are strongly differentiated between and within subpopula ... | 2003 | 12679529 |
| cluster formation and anomalous fundamental diagram in an ant-trail model. | a recently proposed stochastic cellular automaton model [j. phys. a 35, l573 (2002)], motivated by the motions of ants in a trail, is investigated in detail in this paper. the flux of ants in this model is sensitive to the probability of evaporation of pheromone, and the average speed of the ants varies nonmonotonically with their density. this remarkable property is analyzed here using phenomenological and microscopic approximations thereby elucidating the nature of the spatiotemporal organizat ... | 2003 | 12689145 |
| ntp toxicology and carcinogenesis studies of furfural (cas no. 98-01-1) in f344/n rats and b6c3f1 mice (gavage studies). | furfural is used as a precursor for the manufacture of furan, furfuryl alcohol, tetrahydrofuran, and their derivatives and as an industrial solvent. furfural is also present in numerous processed food and beverage products. ntp toxicology and carcinogenesis studies were conducted by administering furfural (99% pure) in corn oil by gavage to groups of f344/n rats and b6c3f1 mice of each sex for 16 days, 13 weeks, or 2 years. genetic toxicology studies were conducted in salmonella typhimurium, mou ... | 1990 | 12692654 |
| anaesthetists' non-technical skills (ants): evaluation of a behavioural marker system. | non-technical skills are critical for good anaesthetic practice but are not addressed explicitly in normal training. realization of the need to train and assess these skills is growing, but these activities must be based on properly developed skills frameworks and validated measurement tools. a prototype behavioural marker system was developed using human factors research techniques. the aim of this study was to conduct an experimental evaluation to establish its basic psychometric properties an ... | 2003 | 12697584 |
| spatial grain and the causes of regional diversity gradients in ants. | gradients of species richness (s; the number of species of a given taxon in a given area and time) are ubiquitous. a key goal in ecology is to understand whether and how the many processes that generate these gradients act at different spatial scales. here we evaluate six hypotheses for diversity gradients with 49 new world ant communities, from tundra to rain forest. we contrast their performance at three spatial grains from s(plot), the average number of ant species nesting in a m2 plot, throu ... | 2003 | 12699224 |
| sympatry and allopatry in two desert ant sister species: how do cataglyphis bicolor and c. savignyi coexist? | two extremely morphologically similar sister species of desert ants, cataglyphis bicolor and c. savignyi, exhibit broadly overlapping distributional ranges within tunisia. in order to analyse the microhabitats of c. bicolor and c. savignyi within the sympatric and allopatric areas of both ant species, the plant species located at 113 different nest sites of the two ant species were determined. in the sympatric area, the two species exhibit a clear-cut nest site segregation. this is not the case ... | 2003 | 12720085 |
| a comparative analysis of morphological and ecological characters of european aphids and lycaenids in relation to ant attendance. | ants are a major environmental factor for many insect species. for example, aphids and lycaenids have evolved an array of associations with ants ranging from obligate myrmecophily to the avoidance of contact. here we (1) analyze the predictive power of different ecological and morphological traits for explaining the strength of the association between ants and aphids/lycaenids and (2) contrast different taxonomic levels with respect to the variance explained by ant attendance. data come from a l ... | 2003 | 12721833 |
| evaluation of the effect on arthropod populations by using deltamethrin to control phloeotribus scarabaeoides bern. (coleoptera: scolytidae) in olive orchards. | field tests were made for the control of an olive insect pest, the olive bark beetle, phloeotribus scarabaeoides (col: scolytidae), using the pyrethroid insecticide deltamethrin (d) and this insecticide combined with ethylene (d+e), an attractant of the olive bark beetle. the tests were run in olive orchards in the provinces of granada and jaén (andalusia, southern spain), treating several olive rows so as to create a barrier effect to control the pest attack. the main objective was to evaluate ... | 2003 | 12729695 |
| genetic evidence for intra- and interspecific slavery in honey ants (genus myrmecocystus). | the new world honey ant species myrmecocystus mimicus is well known for its highly stereotyped territorial tournaments, and for the raids on conspecific nests that can lead to intraspecific slavery. our results from mitochondrial and nuclear markers show that the raided brood emerges in the raiding colony and is subsequently incorporated into the colony's worker force. we also found enslaved conspecifics in a second honey ant species, m. depilis, the sister taxon of m. mimicus, which occurs in s ... | 2003 | 12737658 |
| explaining the abundance of ants in lowland tropical rainforest canopies. | the extraordinary abundance of ants in tropical rainforest canopies has led to speculation that numerous arboreal ant taxa feed principally as "herbivores" of plant and insect exudates. based on nitrogen (n) isotope ratios of plants, known herbivores, arthropod predators, and ants from amazonia and borneo, we find that many arboreal ant species obtain little n through predation and scavenging. microsymbionts of ants and their hemipteran trophobionts might play key roles in the nutrition of taxa ... | 2003 | 12738862 |
| a preliminary study on dicrocoeliasis in egypt, with a general review. | dicrocoelium dendriticum (d. dendriticum) is a lancet-shape liver fluke that affects sheep and mammals including man. human and animal infections have been world widely reported particularly in some of the eastern mediterranean sheep raising countries. infection is acquired by eating the second intermediate host (17 species of ants) with raw fruits, vegetables, herbs or even with the drinking water. as for the first intermediate host, there is about 54 different species of land snails. in spite ... | 2003 | 12739803 |
| molecular phylogeny of crematogaster subgenus decacrema ants (hymenoptera: formicidae) and the colonization of macaranga (euphorbiaceae) trees. | to elucidate the evolution of one of the most species-rich ant-plant symbiotic systems, the association between crematogaster (myrmicinae) and macaranga (euphorbiaceae) in south-east asia, we conducted a phylogenetic analysis of the ant partners. for the phylogenetic analysis partial mitochondrial cytochrome oxidase i and ii were sequenced and maximum parsimony analysis was performed. the analyzed crematogaster of the subgenus decacrema fell into three distinct clades which are also characterize ... | 2003 | 12742749 |
| fire ant venom alkaloid, isosolenopsin a, a potent and selective inhibitor of neuronal nitric oxide synthase. | massive, multiple fire ant, solenopsis invicta, stings are often treated aggressively, particularly in the elderly, despite limited evidence of systemic toxicity due to the venom. over 95% of the s. invicta venom is composed of piperidine alkaloid components, whose toxicity, if any, is unknown. to assess a possible pharmacological basis for systemic toxicity, an alkaloid-rich, protein-free methanol extract of the venom from whole ants was assayed for inhibitory activity on the following nitric o ... | 2003 | 12745988 |
| 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 |
| fluorescence in situ hybridization: a new method for determining primary sex ratio in ants. | the haplodiploid sex determining system in hymenoptera, whereby males develop from haploid eggs and females from diploid eggs, allows females to control the primary sex ratio (the proportion of each sex at oviposition) in response to ecological and/or genetic conditions. surprisingly, primary sex ratio adjustment by queens in eusocial hymenoptera has been poorly studied, because of difficulties in sexing the eggs laid. here, we show that fluorescence in situ hybridization (fish) can be used to a ... | 2003 | 12755891 |
| 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 |
| positive and negative effects of leaf shelters on herbivorous insects: linking multiple herbivore species on a willow. | we experimentally examined the effects on other herbivorous insects of leaf shelters constructed by lepidopteran larvae on a willow, salix miyabeana. several insect species occupied the vacant leaf shelters. our experiment using artificial leaf shelters showed that the number of aphids increased with the number of artificial leaf shelters on a shoot, as did the numbers of three ant species ( camponotus japonicus, lasius hayashi, and myrmica jessensis) that entered leaf shelters to collect aphid ... | 2003 | 12768405 |
| nectar feeding by the ant camponotus mus: intake rate and crop filling as a function of sucrose concentration. | in independent assays, workers of the ant camponotus mus were conditioned to visit an arena where they found a large drop of sucrose solution of different concentrations, from 5 to 70% weight on weight (w/w). single ants were allowed to collect the sucrose solution ad libitum, and feeding time, feeding interruptions, crop load, and intake rates were recorded. feeding time increased exponentially with sucrose concentration, and this relationship was quantitatively described by the increase in vis ... | 1998 | 12769940 |
| jaws that snap: control of mandible movements in the ant mystrium. | ants of the genus mystrium employ a peculiar snap-jaw mechanism in which the closed mandibles cross over to deliver a stunning blow to an adversary within about 0.5 ms. the mandible snapping is preceded by antennation and antennal withdrawal. the strike is initiated by contact of the adversary with mechanosensory hairs at the side of the mandible, and is powered by large yet slow closer muscles whose energy is stored by a catapult mechanism. recording of closer muscle activity indicates that the ... | 1998 | 12769958 |
| survival of atta sexdens workers on different food sources. | leaf-cutting ants belonging to the tribe attini are major herbivores and important agriculture pests in the neotropics, these ants being thought to feed on the sap which exudes from the plant material which they cut and also on the mycelium of a symbiotic fungus that grows on plant material inside their nests in what is called "the fungus garden". however, we have found that the survival of atta sexdens worker ants on leaves, on mycelium of the ants' symbiotic fungus, leucoagaricus gongylophorus ... | 2003 | 12769984 |
| fluid intake rates in ants correlate with their feeding habits. | this study investigates the techniques of nectar feeding in 11 different ant species, and quantitatively compares fluid intake rates over a wide range of nectar concentrations in four species that largely differ in their feeding habits. ants were observed to employ two different techniques for liquid food intake, in which the glossa works either as a passive duct-like structure (sucking), or as an up- and downwards moving shovel (licking). the technique employed for collecting fluids at ad libit ... | 2003 | 12769988 |
| zinc is incorporated into cuticular "tools" after ecdysis: the time course of the zinc distribution in "tools" and whole bodies of an ant and a scorpion. | an understanding of the developmental course of specialized accumulations in the cuticular "tools" of arthropods will give clues to the chemical form, function and biology of these accumulations as well as to their evolutionary history. specimens from individuals representing a range of developmental stages were examined using mev - ion microscopy. we found that zinc, manganese, calcium and chlorine began to accumulate in the mandibular teeth of the ant tapinoma sessile after pre-ecdysial tannin ... | 2003 | 12770014 |
| 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 |