| a new type of exocrine gland and its function in mass recruitment in the ant cylindromyrmex whymperi (formicidae, cerapachyinae). | workers of the ant cylindromyrmex whymperi display mass trail recruitment. bioassays show that the trail pheromone originates from a unique gland between abdominal sternites 6 and 7. the gland has a hitherto unknown structural organization. upon leaving the secretory cell, the duct cell widens to form a sclerotized pear-shaped reservoir chamber, lined with multiple duct cells. each duct thus forms a miniature reservoir for the secretions of each single secretory cells, a novel structural arrange ... | 2001 | 11688416 |
| insecticidal activity of essential oils: octopaminergic sites of action. | a study was conducted to determine the insecticidal activity and mechanism of action of three essential oils (eugenol, alpha-terpineol and cinnamic alcohol) and an equal part mixture (3-blend) against american cockroaches (periplaneta americana). to address species differences in response to treatment with the test oils, carpenter ants (camponotus pennsylvanicus de geer), and german cockroaches (blattella germanica) were included in this study. exposed american cockroaches demonstrated hyperacti ... | 2001 | 11701389 |
| field and allozyme studies investigating optimal mating success in two sympatric spring-ephemeral plants, trillium erectum and t. grandiflorum. | a combination of field experiments and allozyme studies was used to test whether two spring-ephemeral plants growing in eastern north america, trillium erectum and t. grandiflorum (liliaceae), exhibited an optimal outcrossing distance for fruit and seed production. furthermore, the spatial genetic structure of the trillium populations was examined in light of the outcrossing results. in field experiments, recipient plants were pollinated with either self pollen or with pollen from donors growing ... | 2001 | 11703508 |
| sex ratio and wolbachia infection in the ant formica exsecta. | sex allocation data in social hymenoptera provide some of the best tests of kin selection, parent-offspring conflict and sex ratio theories. however, these studies critically depend on controlling for confounding ecological factors and on identifying all parties that potentially manipulate colony sex ratio. it has been suggested that maternally inherited parasites may influence sex allocation in social hymenoptera. if the parasites can influence sex allocation, infected colonies are predicted to ... | 2001 | 11703514 |
| antisocial, an intracellular adaptor protein, is required for myoblast fusion in drosophila. | somatic muscle formation in drosophila requires fusion of muscle founder cells with fusion-competent myoblasts. in a genetic screen for genes that control muscle development, we identified antisocial (ants), a gene that encodes an ankyrin repeat-, tpr repeat-, and ring finger-containing protein, required for myoblast fusion. in ants mutant embryos, founder cells and fusion-competent myoblasts are properly specified and patterned, but they are unable to form myotubes. ants, which is expressed spe ... | 2001 | 11709190 |
| trade-off between chemical and biotic antiherbivore defense in the south east asian plant genus macaranga. | the plant genus macaranga is known for its manifold mutualistic associations with ants. the plants provide food for the ants and in turn get protection from herbivores. depending on the strength of the plant-ant interaction, the plant's investment in ants and the biotic defense derived from them is more or less effective. we conducted a comparative study on tannin content in 12 macaranga species that were selected based on their associations with ants (three nonmyrmecophytes and nine myrmecophyt ... | 2001 | 11710606 |
| identification of a major gene regulating complex social behavior. | colony queen number, a major feature of social organization in fire ants, is associated with worker genotypes at the gene gp-9. we sequenced gp-9 and found that it encodes a pheromone-binding protein, a crucial molecular component in chemical recognition of conspecifics. this suggests that differences in worker gp-9 genotypes between social forms may cause differences in workers' abilities to recognize queens and regulate their numbers. analyses of sequence evolution indicate that regulation of ... | 2002 | 11711637 |
| an oral bioassay for the toxicity of hydramethylnon to individual workers and queens of argentine ants, linepithema humile. | we have developed an oral bioassay to determine the toxicity of hydramethylnon to individual workers and queens of the argentine ant, linepithema humile. we fed seven concentrations of hydramethylnon in suspension to individual workers or queens, determined the amount of hydramethylnon ingested and evaluated the individual ants for mortality 14 days later. at concentrations > or = 0.37 g liter-1, the amount of liquid the queens ingested decreased dramatically, indicating that argentine ant queen ... | 2001 | 11721517 |
| the ecology and evolution of ant association in the lycaenidae (lepidoptera). | the estimated 6000 species of lycaenidae account for about one third of all papilionoidea. the majority of lycaenids have associations with ants that can be facultative or obligate and range from mutualism to parasitism. lycaenid larvae and pupae employ complex chemical and acoustical signals to manipulate ants. cost/benefit analyses have demonstrated multiple trade-offs involved in myrmecophily. both demographic and phylogenetic evidence indicate that ant association has shaped the evolution of ... | 2002 | 11729090 |
| ecological meltdown in predator-free forest fragments. | the manner in which terrestrial ecosystems are regulated is controversial. the "top-down" school holds that predators limit herbivores and thereby prevent them from overexploiting vegetation. "bottom-up" proponents stress the role of plant chemical defenses in limiting plant depredation by herbivores. a set of predator-free islands created by a hydroelectric impoundment in venezuela allows a test of these competing world views. limited area restricts the fauna of small (0.25 to 0.9 hectare) isla ... | 2001 | 11729317 |
| model of droplet dynamics in the argentine ant linepithema humile (mayr). | the formation of droplets of ants linepithema humile (mayr) is observed under certain experimental conditions: a fluctuating aggregate forms at the end of a rod and a droplet containing up to 40 ants eventually falls down. when the flux of incoming ants is sufficient, this process can continue for several hours, leading to the formation and fall of tens of droplets. previous work indicates that the time series of drop-to-drop intervals may result from a nonlinear low-dimensional dynamics, and th ... | 2001 | 11732177 |
| two-category model of task allocation with application to ant societies. | in many network models of interacting units such as cells or insects, the coupling coefficients between units are independent of the state of the units. here we analyze the temporal behavior of units that can switch between two 'category' states according to rules that involve category-dependent coupling coefficients. the behaviors of the category populations resulting from the asynchronous random updating of units are first classified according to the signs of the coupling coefficients using nu ... | 2001 | 11732179 |
| mandible movements in ants. | ants use their mandibles for almost any task, including prey-catching, fighting, leaf-cutting, brood care and communication. the key to the versatility of mandible functions is the mandible closer muscle. in ants, this muscle is generally composed of distinct muscle fiber types that differ in morphology and contractile properties. fast contracting fibers have short sarcomeres (2-3 microm) and attach directly to the closer apodeme, that conveys the muscle power to the mandible joint. slow but for ... | 2001 | 11733162 |
| pets and vermin are associated with high endotoxin levels in house dust. | previous studies have shown that the risk for allergic sensitization is lower in children who grew up on farms and in young adults who were exposed to dogs in early childhood. a higher microbial exposure in general and in particular to endotoxin in early childhood might contribute to this lower risk of atopy. | 2001 | 11737034 |
| [nonconvulsive status epilepticus: experience in 33 patients]. | to review the nonconvulsive status epilepticus diagnosed in a general hospital in order to identify its frequency, electroclinical characteristics and response to medical treatment. patients ants and methods: a retrospective study of 33 cases of nonconvulsive status epilepticus was undertaken. the diagnosis was based on clinical and eeg manifestations. data regarding their clinical presentation, previous epilepsy, etiology of the status, its medical management and outcome were analysed. | 2001 | 11742619 |
| angiotensin peptides modulate bradykinin levels in the interstitium of the dog heart in vivo. | we previously demonstrated the substantial capacity for angiotensin (ang) ii formation in the interstitium of the dog heart in vivo. the current study tested the hypothesis that interstitial fluid (isf) bradykinin (bk) is influenced by ang ii formation. four microdialysis probes were inserted into the left ventricular myocardium of eight open-chest anesthetized dogs. the probe effluent was collected during four stages in each dog. probes 1 and 3 sequentially delivered: 1) buffer; 2) ang i (15 mi ... | 2002 | 11752132 |
| down the tube: pollinators, predators, and the evolution of flower shape in the alpine skypilot, polemonium viscosum. | we address how a conflict between pollinator attraction and avoidance of flower predation influences the evolution of flower shape in polemonium viscosum. flower shape in p. viscosum is the product of an isometric relationship between genetically correlated (ra = 0.70) corolla flare and length. bumblebee pollinators preferentially visit flowers that are more flared and have longer tubes, selecting for a funnel-shaped corolla. however, flower shape also influences nectar-foraging ants that sever ... | 2001 | 11761057 |
| partial incompatibility between ants and symbiotic fungi in two sympatric species of acromyrmex leaf-cutting ants. | we investigate the nature and duration of incompatibility between certain combinations of acromyrmex leaf-cutting ants and symbiotic fungi, taken from sympatric colonies of the same or a related species. ant-fungus incompatibility appeared to be largely independent of the ant species involved, but could be explained partly by genetic differences among the fungus cultivars. following current theoretical considerations, we develop a hypothesis, originally proposed by s. a. frank, that the observed ... | 2001 | 11761059 |
| on-line capillary electrophoresis with mass spectrometry detection for the analysis of carbohydrates after derivatization with 8-aminonaphthalene-1,3,6-trisulfonic acid. | capillary electrophoresis (ce) with mass spectrometry (ms) detection is an ideal tool for analytical use, which combines a nano quantity assay with mass determination. carbohydrate analysis has always been a challenge because of the inherent structural complexity and the lack of a chromophore, unless derivatization is used. here we use the derivatization of carbohydrates with a fluorophore, 8-aminonaphthalene-1,3,6-trisulfonic acid (ants). this chromophore has two advantages, first, it facilitat ... | 2001 | 11762766 |
| contributions to and review of dicrocoeliosis, with special reference to the intermediate hosts of dicrocoelium dendriticum. | an epidemiological study on dicrocoeliosis caused by dicrocoelium dendriticum was carried out on sheep, molluscs and ants in the mountains of león province (nw spain) between 1987-1991. the results concerning the intermediate hosts and a review of some aspects of dicrocoeliosis are summarized. mollusc collection for the helminthological study was random throughout the study area at fortnightly intervals. twenty-nine gastropoda species were identified. d. dendriticum infection was only detected i ... | 2001 | 11769295 |
| effects of aromatic cedar mulch on the argentine ant and the odorous house ant (hymenoptera: formicidae). | in laboratory studies, the argentine ant, linepithema humile (mayr), and the odorous house ant, tapinoma sessile (say), avoided aromatic cedar mulch as a nesting substrate. both ant species were killed when confined with fresh aromatic cedar mulch in sealed containers. however, when confined with cedar mulch that had been aged outdoors for up to 140 d, mortality of l. humile was complete regardless of mulch age, whereas t. sessile mortality declined significantly over the mulch-aging period. arg ... | 2001 | 11777059 |
| evolution of sociality in a primitively eusocial lineage of bees. | eusociality is a major evolutionary innovation involving alterations in life history, morphology, and behavior. advanced eusocial insects, such as ants, termites, and corbiculate bees, cannot provide insights into the earliest stages of eusocial evolution because eusociality in these taxa evolved long ago (in the cretaceous) and close solitary relatives are no longer extant. in contrast, primitively eusocial insects, such as halictid bees, provide insights into the early stages of eusocial evolu ... | 2002 | 11782550 |
| homosexual tandem running as selfish herd in reticulitermes speratus: novel antipredatory behavior in termites. | we investigated the predator avoidance mechanism of post-swarming alates of the lower subterranean termite, reticulitermes speratus kolbe. in some lower termites, homosexual tandem running is observed in addition to ordinary heterosexual tandem running. an experiment designed to compare the risk of predation by a termite-hunting ant, brachyponera chinensis emery, showed that homosexual tandem running reduced the predation risk until termites encounter the opposite sex. since an individual ant ca ... | 2002 | 11786032 |
| behavioral and chemical analysis of venom gland secretion of queens of the ant solenopsis geminata. | bioassays in a y-tube olfactometer showed that workers of solenopsis geminata (hymenoptera: formicidae) were attracted to venom gland extracts of queens. gas chromatography coupled mass spectrometry analysis of individual glands of queens of s. geminata showed that the secretion is composed mainly of a large amount of 2-alkyl-6-methylpiperidine alkaloids and a tiny amount of a delta-lactone and a a-pyrone, which have been earlier identified as components of the queen attractant pheromone of sole ... | 2001 | 11789950 |
| capillary electrophoresis/electrospray ion trap mass spectrometry for the analysis of negatively charged derivatized and underivatized glycans. | the increasing interest in the development of glycoproteins for therapeutic purposes has created a greater demand for methods to characterize the sugar moieties bound to them. traditionally, released carbohydrates are derivatized using such methods as permethylation or fluorescent tagging prior to analysis by high performance liquid chromatography (hplc), capillary electrophoresis (ce), or direct infusion mass spectrometry. however, little research has been performed using ce with on-line mass s ... | 2002 | 11803540 |
| evidence of intracolony transmission of thelohania solenopsae (microsporidia: thelohaniidae) in red imported fire ants (hymenoptera: formicidae) and the first report of spores from pupae. | red imported fire ant, solenopsis invicta, colonies were infected horizontally by introducing live brood (mainly larvae and pupae) infected with thelohania solenopsae. live, infected brood introduced into uninfected colonies were adopted and raised to adulthood instead of being executed by the recipient colony. introductions of infected larvae with uninfected pupae, which eclose into adult worker caste fire ants, resulted in an 80% infection rate of the inoculated colonies. infections from intro ... | 2001 | 11812115 |
| [the use of insecticide fumigant canister to protect an insectarium and its residual effect against triatomine bugs, in laboratory conditions]. | an insecticide fumigant canister based on synthetic pyrethroids and dichlorvos was employed against cockroaches and ants which were invading an insectarium used for rearing triatominae. after removal of the triatominae, the canister was activated and found to kill all the invading insects within 48 hours. possible residual action against triatomines was then monitored by a 24-hour exposure of eggs, nymphs and adults of triatoma infestans, panstrongylus megistus and rhodnius neglectus in the trea ... | 2001 | 11813055 |
| egocentric information helps desert ants to navigate around familiar obstacles. | homing ants have been shown to associate directional information with familiar landmarks. the sight of these local cues might either directly guide the path of the ant or it might activate a landmark-based vector that points towards the goal position. in either case, the ants define their courses within allocentric systems of reference. here, we show that desert ants, cataglyphis fortis, forced to run along a devious path can use egocentric information as well. the ants were trained to deviate f ... | 2001 | 11815643 |
| neuroendocrine tumours of the duodenum. clinical aspects, pathomorphology and therapy. | neuroendocrine tumours (nts) of the duodenum are uncommon neoplasms. they represent a heterogeneous spectrum of subtypes and may be associated with von recklinghausen's disease type i (vrd) and multiple endocrine neoplasia type i. there are few studies concerning the biological characteristics and adequate therapy of these tumours. | 2002 | 11819111 |
| restricted effective queen dispersal at a microgeographic scale in polygynous populations of the ant formica exsecta. | ecological constraints on effective dispersal have been suggested to be a key factor influencing social evolution in animal societies as well as the shift from single queen colonies (monogyny) to multiple queen colonies (polygyny) in ants. however, little is known about the effective dispersal patterns of ant queens. here we investigate the microgeographic genetic structure of mitochondrial haplotypes in polygynous populations of the ant formica exsecta, both between pastures and among nests wit ... | 2001 | 11831664 |
| research of the holiday kind. ants. | | 2001 | 11841007 |
| gone fishing: tool use in animals. | chimpanzees impress and fascinate us with their use of tools, including twigs to 'fish' for termites and leaves to soak up liquids. but there are many intriguing examples of tool use described across the animal kingdom. ants use grain to carry honey, and elephants can grip fly switches in their prehensile trunks. even animals without limbs may use tools. | 2002 | 11852280 |
| extensive exchange of fungal cultivars between sympatric species of fungus-growing ants. | fungal cultivars of fungus-growing ants (attini, formicidae) are carried by dispersing queens from parent to offspring nest. this vertical cultivar transmission between generations is thought to result in long-term ant-fungus coevolution and selection for beneficial cultivar traits that maximize harvests and thus colony productivity. in contrast to this traditional view of vertical cultivar transmission, frequent horizontal cultivar transmission between ant species is implicated by a phylogeneti ... | 2002 | 11856421 |
| dufour gland contents of ants of the cataglyphis bicolor group. | the species of desert-dwelling ants of the cataglyphis bicolor (hymenoptera: formicidae) group are difficult to distinguish by morphological features. analysis of the secretion from the dufour glands of workers of a number of colonies was undertaken to see if it provided a clear test of species. linked 6c-ms showed in all samples straight and branched-chain alkanes, linear alkenes, ketones, aldehydes, acetates, and a group of c22 to c28 esters not previously identified in this genus. contents of ... | 2002 | 11868680 |
| formidable catalogue puts army of ants online. | | 2002 | 11894065 |
| development of thelohania solenopsae in red imported fire ants solenopsis invicta from polygynous colonies results in formation of three spore types. | | 2001 | 11906091 |
| the visual centring response in desert ants, cataglyphis fortis. | when negotiating their way through cluttered environments, desert ants, cataglyphis fortis, tend to run along the midlines of the alleys formed by adjacent low shrubs. this 'centring response' was investigated by inducing foraging ants to walk through artificial channels. the sidewalls of the channel were either homogeneously black or provided with stationary or moving black-and-white gratings. the speed of motion and the spatial period of the gratings and the height of the walls could be varied ... | 2002 | 11907048 |
| the role of the symbiotic fungus in the digestive metabolism of two species of fungus-growing ants. | leaf-cutting ants live in an obligatory symbiosis with a fungus which they grow on fresh leaves harvested by workers. this study attempts to clarify the respective role of ants and fungus in the degradation of plant material, in order to highlight the evolutionary basis of this mutualistic association. the symbiotic system of two ant species, acromyrmex subterraneus subterraneus and acromyrmex crassispinus, was investigated. to identify the digestive carbohydrases, a total of 19 specific and syn ... | 2002 | 11916111 |
| antipredator defense of biological control agent oxyops vitiosa is mediated by plant volatiles sequestered from the host plant melaleuca quinquenervia. | the weevil oxyops vitiosa is an australian species imported to florida, usa, for the biological control of the invasive weed species melaleuca quinquenervia. larvae of this species feed on leaves of their host and produce a shiny orange secretion that covers the integument. when this secretion is applied at physiological concentrations to dog food bait, fire ant consumption and visitation are significantly reduced. gas chromatographic analysis indicates that the larval secretion qualitatively an ... | 2002 | 11925069 |
| warring ants: lessons from lanchester's laws of combat? | | 2002 | 11937675 |
| brave new worlds: trophallaxis and the origin of society in the early twentieth century. | trophallaxis, the process of feeding by mutual regurgitation amongst insects, was named by the north american entomologist william morton wheeler in 1918. i argue that entomologists, both before and after 1918, saw mutual feeding as an integral part of the behavioral whole of the nest, and moreover related its explanatory power to theories about human society. in particular, feeding behavior was seen as the key to the riddle of the origin of sociality. i show how entomologists' precise interpret ... | 2002 | 11954038 |
| evolution of supercolonies: the argentine ants of southern europe. | some ants have an extraordinary social organization, called unicoloniality, whereby individuals mix freely among physically separated nests. this type of social organization is not only a key attribute responsible for the ecological domination of these ants, but also an evolutionary paradox and a potential problem for kin selection theory because relatedness between nest mates is effectively zero. the introduction of the argentine ant in europe was apparently accompanied by a dramatic loss of in ... | 2002 | 11959924 |
| stinging ants. | ants belong to the order hymenoptera, along with bees, wasps, yellow jackets, etc., they are the most successful animal genera in this world. it is their selfless social structure which accounts for their huge impact. their effect on man ranges from the parasol ant, which makes plant cultivation untenable in certain parts of south america, to solenopsis invicta in the southeastern united states of america, which kill ground dwelling birds and small animals, harass livestock, and renders farmland ... | 2001 | 11964710 |
| viral, parasitic and prion diseases of farmed deer and bison. | the most important viral disease of farmed deer and bison is malignant catarrhal fever. the other herpesviruses which have been isolated from these species are briefly described. other viral agents that are recognised in these animals, including adenovirus, parapox, foot and mouth disease, bluetongue, epizootic haemorrhagic disease, bovine virus diarrhoea, rotavirus and coronavirus, are also discussed. ectoparasites of importance in this group in various parts of the world include a variety of t ... | 2002 | 11974612 |
| the use of invertebrates to detect small-scale habitat heterogeneity and its application to restoration practices. | recent conceptual and technological solutions to biodiversity assessment allow large numbers of invertebrate specimens to be processed rapidly and provide researchers and practitioners with a unique tool for characterizing habitats. one application of these advances is the ability to detect and monitor small-scale habitat heterogeneity and so provide a measure of ecosystem restoration. this case study presents a test of the efficacy of using invertebrates to assess and monitor ecological restora ... | 2002 | 12002286 |
| distance estimation in the third dimension in desert ants. | desert ants of the genus cataglyphis perform large-scale foraging excursions from which they return to their nest by path integration. they do so by integrating courses steered and the distances travelled into a continually updated home vector. while it is known that the angular orientation is based on skylight cues, it still is largely enigmatic how the ants measure distances travelled. we extended the ants' task into the third dimension by training them to walk within an array of uphill and do ... | 2002 | 12012098 |
| the diversity of microorganisms associated with acromyrmex leafcutter ants. | molecular biological techniques are dramatically changing our view of microbial diversity in almost any environment that has so far been investigated. this study presents a systematic survey of the microbial diversity associated with a population of acromyrmex leafcutter ants. in contrast to previous studies on social insects, which targeted specific groups of symbionts occurring in the gut (termites, tetraponera ants) or in specialised cells (camponotus ants) the objective of our present study ... | 2002 | 12019020 |
| mimicry of host cuticular hydrocarbons by salticid spider cosmophasis bitaeniata that preys on larvae of tree ants oecophylla smaragdina. | the salticid spider cosmophasis bitaeniata preys on the larvae of the green tree ant oecophylla smaragdina. gas chromatography (gc) and gas chromatography-mass spectrometry (gc-ms) reveal that the cuticle of c. bitaeniata mimics the mono- and dimethylalkanes of the cuticle of its prey. recognition bioassays with extracts of the cuticular hydrocarbons of ants and spiders revealed that foraging major workers did not respond aggressively to the extracts of the spiders or conspecific nestmates, but ... | 2002 | 12035930 |
| parasitoid secretions provoke ant warfare. | insect social parasites are extreme specialists that typically use mimicry or stealth to enter ant colonies to exploit the rich, but fiercely protected, resources within their nests. here we show how a parasitic wasp (parasitoid) contrives to reach its host, itself an endangered species of social parasite that lives inside the brood chambers of ant nests, by releasing semiochemicals to induce in-fighting between worker ants, locking the colony in combat and leaving it underprotected. four of the ... | 2002 | 12037556 |
| daughters inherit colonies from mothers in the 'living-fossil' ant nothomyrmecia macrops. | newly mated queens of monogynous (single queen) ants usually found their colonies independently, without the assistance of workers. in polygynous (multiple queen) species queens are often adopted back into their natal nest and new colonies are established by budding. we report that the australian 'living-fossil' ant, nothomyrmecia macrops, is exceptional in that its single queen can be replaced by one of the colony's daughters. this type of colony founding is an interesting alternative reproduct ... | 2002 | 12046624 |
| genetics of social behaviour in fire ants. | a recent study is the first to sequence a gene known to underlie a complex social phenotype. in the fire ant, solenopsis invicta, a single allelic difference at the gp-9 locus specifies the number of queens a colony has, and hence the social structure of the colony. gp-9 appears to encode a protein implicated in chemical recognition of nestmates, consistent with workers determining queen number by selectively executing queens as a function of workers' and queens' gp-9 genotypes. other solenopsis ... | 2002 | 12047935 |
| effects of large mammalian herbivores and ant symbionts on condensed tannins of acacia drepanolobium in kenya. | condensed tannins have been considered to be important inducible defenses against mammalian herbivory. we tested for differences in condensed tannin defenses in acacia drepanolobium in kenya over two years among different large mammalian herbivore treatments [total exclusion, antelope only, and megaherbivore (elephants and giraffes) + antelope] and with four different ant symbiont species on the trees. we predicted that (1) condensed tannin concentrations would be lowest in the mammal treatment ... | 2002 | 12049231 |
| chimpanzees and the mathematics of battle. | recent experiments have demonstrated the importance of numerical assessment in animal contests. nevertheless, few attempts have been made to model explicitly the relationship between the relative number of combatants on each side and the costs and benefits of entering a contest. one framework that may be especially suitable for making such explicit predictions is lanchester's theory of combat, which has proved useful for understanding combat strategies in humans and several species of ants. we s ... | 2002 | 12061952 |
| fire ants in australia: a new medical and ecological hazard. | | 2002 | 12064981 |
| anaphylaxis due to red imported fire ant sting. | the invasive red imported fire ant (solenopsis invicta buren) is well established at two locations in the brisbane area, and we report a patient with anaphylaxis after a sting. the potential for anaphylactic events in australia due to s. invicta will be greater than for native ants because of its unusual venom, its habit of forming supercolonies in grassy areas, and its aggressive group territorial defence, which can result in multiple stings. | 2002 | 12064982 |
| genetic variability and social structure of colonies in acromyrmex heyeri and a. striatus (hymenoptera: formicidae). | the breeding structure of both colony and population of social insects can be examined by genetic analysis. colonies of the leaf-cutting ants acromyrmex heyeri and a. striatus (myrmicinae, attini) were thus analyzed for isoenzyme systems mdh, a-gpdh, and amy to describe genotype variability and social structure. a total of five loci were investigated (three for amylase and one for each other system). ninety-seven colonies of a. heyeri and 103 of a. striatus were sampled in different localities i ... | 2001 | 12071324 |
| field evaluation of potential of alarm pheromone compounds to enhance baits for control of grass-cutting ants (hymenoptera: formicidae). | leaf-cutting ants are important economic pests of the neotropics, and the most common method of control involves the use of insecticidal baits. baits that are currently available exhibit low attractiveness to grass-cutting species, thus there is a need to develop improved baits. the potential for using alarm pheromone compounds to enhance the attractiveness and subsequent harvest of baits was examined for two economically important species of grass-cutting ant, atta bisphaerica (forel) and atta ... | 2002 | 12075997 |
| impact of thelohania solenopsae (microsporidia: thelohaniidae) on polygyne colonies of red imported fire ants (hymenoptera: formicidae). | three studies were conducted to assess the effects of the entomopathogen thelohania solenopsae on polygynous, red imported fire ant, solenopsis invicta buren, colonies. a total of 57 of 122 queens (46.7%) from nine, field-collected, polygyne, s. invicta colonies, was infected with t. solenopsae. infection rate of queens for each colony ranged from 25 to 75%. laboratory colonies of polygyne s. invicta, with three to 12 queens, were inoculated and infected with t. solenopsae. brood levels in all i ... | 2002 | 12076000 |
| recommendations for prevention and management of fire ant infestation of health care facilities. | the range of imported fire ants now includes most of the southeastern united states, parts of the southwest, portions of the east and west coasts, and puerto rico. increasingly, fire ant attacks on patients in health care facilities have been reported. in this paper, we provide recommendations for fire ant control in and around health care facilities that should help prevent building infestation and further attacks. in addition, we provide algorithms detailing fire ant prevention strategies (ind ... | 2002 | 12081218 |
| dynamics of aggregation and emergence of cooperation. | aggregation is one of the most basic social phenomena, and many activities of social insects are linked to it. for instance, the selection of a valuable site and the spatial organization of the population are very often by-products of amplifications based on the local density of nestmates. the patterns of aggregation are very diverse, ranging from the gathering of all animals in a unique site to their splitting between several ones. one might question how these multiple patterns emerge. do ants ... | 2002 | 12086998 |
| complexity of environment and parsimony of decision rules in insect societies. | this paper shows how colonies of social insects process information and solve problems in a complex environment, while keeping some parsimony at the level of the individuals' decision rules. two studies on ant foraging reveal the diversity of adaptive colony-level patterns that can be generated through self-organization, based on the same individual-level recruitment rules. regarding prey scavenging, the "ability to retrieve the prey" rule accounts for changes in foraging patterns, with increasi ... | 2002 | 12086999 |
| individual complexity and self-organization in foraging by leaf-cutting ants. | leaf-cutting ants cut vegetation into small fragments that they transport to the nest, where a symbiotic fungus cultivated by the ants processes the material. since the harvested leaf fragments are incorporated into the fungus garden and not directly consumed by the workers, it is expected that foraging workers select plants by responding to those physical or chemical traits that promote maximal fungal growth, irrespective of the potential direct effects of these leaf features on them. in this p ... | 2002 | 12087004 |
| the use of alarm pheromones to enhance bait harvest by grass-cutting ants. | the enhancement of bait for the control of grass-cutting ants was investigated using two species of grass-cutting ant, atta bisphaerica (forel) and atta capiguara (gonçalves) (hymenoptera: formicidae). bait was applied in loose piles to obtain a direct relationship between ant attraction and bait harvest. enhancement with alarm pheromone compounds significantly increased the attractiveness and harvest of bait under certain conditions. a large proportion of the ants attracted to the enhanced bait ... | 2002 | 12088538 |
| visual navigation in desert ants cataglyphis fortis: are snapshots coupled to a celestial system of reference? | central-place foraging insects such as desert ants of the genus cataglyphis use both path integration and landmarks to navigate during foraging excursions. the use of landmark information and a celestial system of reference for nest location was investigated by training desert ants returning from an artificial feeder to find the nest at one of four alternative positions located asymmetrically inside a four-cylinder landmark array. the cylindrical landmarks were all of the same size and arranged ... | 2002 | 12089203 |
| exploratory studies of classical conditioning of the preoral cavity in harnessed carpenter ants (camponotus pennsylvanicus). | an attempt was made to classically condition the mouthparts of harnessed worker ants (camponotus pennsylvanicus) in anticipation of feeding. experiments were designed to investigate classical conditioning with one cs, discrimination between two css, and pseudoconditioning. analysis indicated a small acquisition effect that could be accounted for by pseudoconditioning. the preparation can be used to study nonassociative learning and some instrumental conditioning situations. | 2002 | 12090495 |
| memory use in insect visual navigation. | the navigational strategies that are used by foraging ants and bees to reach a goal are similar to those of birds and mammals. species from all these groups use path integration and memories of visual landmarks to navigate through familiar terrain. insects have far fewer neural resources than vertebrates, so data from insects might be useful in revealing the essential components of efficient navigation. recent work on ants and bees has uncovered a major role for associative links between long-te ... | 2002 | 12094210 |
| temporal and spatial patterns of seed dispersal in two cistus species (cistaceae). | cistus species are obligate seeding, early colonizers that follow disturbance, particularly fire, in mediterranean ecosystems. we studied seed release, seed dispersal and soil seed populations in stands of cistus ladanifer and c. libanotis. seed release started in mid- to late summer (c. ladanifer) or in early autumn (c libanotis), and continued for a very extended period: 8-10 months in c. ladanifer, and for a mean of 16 months in c. libanotis. the xerochastic capsules of both species released ... | 2002 | 12096803 |
| theoretical biology: ants on a turing trail. | | 2002 | 12110876 |
| evolution of the gene network underlying wing polyphenism in ants. | wing polyphenism in ants evolved once, 125 million years ago, and has been a key to their amazing evolutionary success. we characterized the expression of several genes within the network underlying the wing primordia of reproductive (winged) and sterile (wingless) ant castes. we show that the expression of several genes within the network is conserved in the winged castes of four ant species, whereas points of interruption within the network in the wingless castes are evolutionarily labile. the ... | 2002 | 12114626 |
| view-based navigation in insects: how wood ants (formica rufa l.) look at and are guided by extended landmarks. | bees, wasps and ants learn landmarks as views from particular vantage points, storing the retinal positions of landmark edges. by moving so as to minimise the difference between their stored and current view, they can return to the vantage point from which a view was taken. we have examined what wood ants learn about a laterally placed, extended landmark, a wall, while walking parallel to it to reach a feeder and how they use this stored information to guide their path. manipulation of the heigh ... | 2002 | 12124373 |
| hemolymph of reproductives of solenopsis invicta (hymenoptera: formicidae)-amino acids, proteins and sugars. | free amino acid composition and carbohydrate and protein concentration of the hemolymph of the pupal and adult stages of reproductives of solenopsis invicta are presented. the physico-chemical properties of the hemolymph differ between both sexes of fire ants during development. male alates (459 mmol/kg) have a higher osmolality than pupae (388 mmol/kg). osmolality during the pupal stage was 428 mmol/kg, decreasing to 354 mmol/kg soon after de-alation and increasing again to 463 mmol/kg in activ ... | 2002 | 12128057 |
| convergent development of low-relatedness supercolonies in myrmica ants. | many ant species have independently evolved colony structures with multiple queens and very low relatedness among nestmate workers, but it has remained unclear whether low-relatedness kin structures can repeatedly arise in populations of the same species. here we report a study of danish island populations of the red ant myrmica sulcinodis and show that it is likely that such repeated developments occur. two microsatellite loci were used to estimate genetic differentiation (f(st)) among three po ... | 2002 | 12136409 |
| the effect of fibrillar a beta 1-40 on membrane fluidity and permeability. | the time course of a beta fibril formation was characterized using a variety of assays. the effect of a beta on the membrane fluidity and permeability was assessed by monitoring the anisotropy of the fluorescent probe dph and tma-dph and measuring the release of vesicle-entrapped with three different molecular weight fluorescence probes (ants/dpx, calcein, fd-4). the results show fibrils had formed after 4 days. aggregated a beta may decrease the membrane fluidity and induce the leakage of ants ... | 2002 | 12141916 |
| win-shift and win-stay learning in the short-beaked echidna (tachyglossus aculeatus). | numerous previous investigators have explained species differences in spatial memory performance in terms of differences in foraging ecology. in three experiments we attempted to extend these findings by examining the extent to which the spatial memory performance of echidnas (or "spiny anteaters") can be understood in terms of the spatio-temporal distribution of their prey (ants and termites). this is a species and a foraging situation that have not been examined in this way before. echidnas we ... | 2002 | 12150039 |
| diffusional water permeability (pdw) of adult and neonatal rabbit renal brush border membrane vesicles. | we have shown that there is a maturational increase in osmotic water permeability (pf) of rabbit renal brush border membrane vesicles (bbmv). the purpose of the present study was to further investigate the changes in proximal tubule water transport that occur during postnatal development. diffusional water permeability (pdw) has not been measured directly in adult or neonatal bbmv. we validated the method described by ye and verkman (simultaneous optical measurement of osmotic and diffusional wa ... | 2002 | 12163975 |
| sperm structure and ultrastructure of the fire ant solenopsis invicta (buren) (hymenoptera, formicidae). | the spermatozoa of solenopsis invicta are long and slender, measuring about 70 microm in length, of which the head region measures approximately 13 microm. the head consists of an acrosome formed by an acrosomal vesicle covering a perforatorium and a nucleus. this latter measures about 12 microm, has compact chromatin, and many translucent areas. the flagellum consists of an axoneme of 9+9+2 microtubules that begins just below the nuclear base. the two mitochondrial derivatives are of almost equ ... | 2002 | 12165248 |
| separation and electrophoretic behaviour of 8-aminonaphthalene-1,3,6-trisulfonic acid-derivatized oligosaccharides by capillary electrophoresis. | the mixture of the hydrolyzate of dextran was derivatized with 8-aminonaphthalene-1,3,6-trisulfonic acid(ants) by reductive amination, then the derivatives were separated by capillary zone electrophoresis in 50 mmol/l phosphate, ph 2.5 electrophoretic buffer and in the buffer of 100mmol/l disodium tetraborate, ph 9.3, respectively. two-dimensional mapping of the series of linear dextranoligosaccharide derivatives was obtained by plotting their relative electrophoretic mobilities in acidic buffer ... | 1998 | 12168020 |
| genomic organization and transcription of satellite dna in the ant aphaenogaster subterranea (hymenoptera, formicidae). | a satellite dna family (apsu) was isolated and characterized in the ant aphaenogaster subterranea. this satellite dna is organized in tandem repeats of 162 bp and is relatively at rich (51.9%). sequence analysis showed a high level of homogeneity between monomers. loss of satellite dna has been detected in queens in relation to workers, because the amount of satellite dna in queens is about 25% of the amount found in workers. restriction analysis of the total dna with methylation-sensitive enzym ... | 2002 | 12175063 |
| variable selection for qsar by artificial ant colony systems. | derivation of quantitative structure-activity relationships (qsar) usually involves computational models that relate a set of input variables describing the structural properties of the molecules for which the activity has been measured to the output variable representing activity. many of the input variables may be correlated, and it is therefore often desirable to select an optimal subset of the input variables that results in the most predictive model. in this paper we describe an optimizatio ... | 2002 | 12184383 |
| identifying the transition between single and multiple mating of queens in fungus-growing ants. | obligate mating of females (queens) with multiple males has evolved only rarely in social hymenoptera (ants, social bees, social wasps) and for reasons that are fundamentally different from those underlying multiple mating in other animals. the monophyletic tribe of ('attine') fungus-growing ants is known to include evolutionarily derived genera with obligate multiple mating (the acromyrmex and atta leafcutter ants) as well as phylogenetically basal genera with exclusively single mating (e.g. ap ... | 2002 | 12184823 |
| [spatial distribution of cordyceps spp. (ascomycotina: clavicipitaceae) and its impact on the ants in forests of amazonian colombian foothill]. | entomopathogenic fungi of the genus cordyceps were sampled in the foothills of the colombian amazon region (450-600 msnm altitude. january and may, 1998, i.e. dry and wet seasons, respectively). healthy and cordyceps-parasitized ants from a nearly pristine, a naturally disturbed and a human-disturbed forests were collected on 100 quadrants (1 m2) per forest. litter, shrubs and trunks were explored as substrates, and samples were gathered in vertical strata from 50 cm to 2 m high. azteca was the ... | 2001 | 12189826 |
| diagnostic problems associated with cadaveric trauma from animal activity. | analysis of a series of deaths between 1986 and 2001 resulting from natural disease, accidents, suicides, and homicide, where postmortem animal activity had traumatized bodies, was undertaken at the forensic science center in adelaide to demonstrate the range of lesions that may occur and problems in interpretation that result. tissue damage had been caused by a variety of animals, including fly larvae, ants, birds, dogs, rodents, sea lice, and sharks. postmortem animal activity had disguised in ... | 2002 | 12198348 |
| human spatial representation: insights from animals. | human navigation is special: we use geographic maps to capture a world far beyond our unaided locomotion. in consequence, human navigation is widely thought to depend on internalized versions of these maps - enduring, geocentric 'cognitive maps' capturing diverse information about the environment. contrary to this view, we argue that human navigation is best studied in relation to research on navigating animals as humble as ants. this research provides evidence that animals, including humans, na ... | 2002 | 12200179 |
| colony-level impacts of parasitoid flies on fire ants. | the red imported fire ant is becoming a global ecological problem, having invaded the united states, puerto rico, new zealand and, most recently, australia. in its established areas, this pest is devastating natural biodiversity. early attempts to halt fire ant expansion with pesticides actually enhanced its spread. phorid fly parasitoids from south america have now been introduced into the united states as potential biological control agents of the red imported fire ant, but the impact of these ... | 2002 | 12204130 |
| two-level evolution of foraging agent communities. | this paper presents simulation results of artificial foraging agent communities. the goal of each agent in the community is to find food. once a food source is found, agents eat portions of it and carry some other portions to the nest (in a manner similar to ants) until the food is depleted. agents may also communicate food positions when they are near each other. they are given a set of genes that control several characteristics, such as their activity, memory, scepticism, lying, etc. these gen ... | 2002 | 12204439 |
| comparative social biology of basal taxa of ants and termites. | lacking a comprehensive fossil record, solitary representatives of the taxa, and/or a definitive phylogeny of closely related insects, comparison of the life history and social biology of basal, living groups is one of the few available options for developing inferences regarding the early eusocial evolution of ants and termites. comparisons of a select group of basal formicid and isopteran taxa suggest that the reproductive organization of colonies and their patterns of division of labor were p ... | 2003 | 12208813 |
| pretender punishment induced by chemical signalling in a queenless ant. | animal societies are stages for both conflict and cooperation. reproduction is often monopolized by one or a few individuals who behave aggressively to prevent subordinates from reproducing (for example, naked mole-rats, wasps and ants). here we report an unusual mechanism by which the dominant individual maintains reproductive control. in the queenless ant dinoponera quadriceps, only the alpha female reproduces. if the alpha is challenged by another female she chemically marks the pretender who ... | 2002 | 12214231 |
| comparing an ipm pilot program to a traditional cover spray program in commercial landscapes. | an integrated pest management (ipm) pilot program for landscape plants was implemented during 1997 and 1998 on two commercial, two residential, and one institutional property managed by landscape professionals. when compared with preprogram, calendar-based cover spray program costs at these sites in 1996, the ipm program was cost-effective at one of the five sites in both 1997 and 1998, and cost effective at a second additional site in 1998 when the cooperator, initially skeptical of ipm, discon ... | 2002 | 12216822 |
| a queen pheromone induces workers to kill sexual larvae in colonies of the red imported fire ant (solenopsis invicta). | we conducted five bioassays to study how queens control the execution of sexual larvae by workers in colonies of the red imported fire ant, solenopsis invicta. in each assay, subset colonies were made from many large polygyne colonies, and the 20 sexual larvae they contained were monitored over time. sexual larvae mostly survived in queenless colonies, but were mostly killed in colonies with a single dealated queen, regardless of whether or not the queen was fertilized. the larvae were also kill ... | 2002 | 12216859 |
| gamergates in the myrmicine genus metapone (hymenoptera: formicidae). | gamergates (i.e. mated reproductive workers) are mostly known from ant species within the ponerinae. we report here the discovery of gamergates in two species of the subfamily myrmicinae. until now, mated reproductive females in colonies of myrmicine species have been considered morphologically distinct from the worker caste. however, in two species of the myrmicine metapone (metapone madagascarica and a newly discovered, not yet described metapone species) all workers have six ovarioles and a s ... | 2002 | 12216860 |
| 2-nitroethenylbenzenes as natural products in millipede defense secretions. | the white millipede eucondylodesmus elegans miyosi (polydesmida: doratodesmidae) secretes odoriferous droplets from the glands on both lateral surfaces of its body segments. the secretion was shown to be composed of a mixture of (1e)- and (1z)-2-nitroethenylbenzenes (2-3 microg per millipede), identified by gc/ms analyses and synthesis. this is the first identification of these compounds as natural products. a granulated sugar block baited with the synthetic compound (more than 0.71 microg) demo ... | 2002 | 12216861 |
| how do ants stick out their tongues? | the mouthparts are very important tools for almost any task performed by ants. in particular, the labiomaxillary complex is essential for food intake. in the present study we investigated the anatomical design of the labiomaxillary complex in various ant species, focusing on movement mechanisms. six labial and six maxillary muscles with different functions control the several joints and ensure the proper performance of the labiomaxillary complex. according to our measurements of sarcomere length ... | 2002 | 12219342 |
| modeling the dynamics of ant colony optimization. | the dynamics of ant colony optimization (aco) algorithms is studied using a deterministic model that assumes an average expected behavior of the algorithms. the aco optimization metaheuristic is an iterative approach, where in every iteration, artificial ants construct solutions randomly but guided by pheromone information stemming from former ants that found good solutions. the behavior of aco algorithms and the aco model are analyzed for certain types of permutation problems. it is shown analy ... | 2002 | 12227995 |
| rank orders and division of labour among unrelated cofounding ant queens. | young, unrelated queens may cooperate in colony founding (pleometrosis) in many species of ants. whereas the founding queens of many 'advanced' species rely completely on body reserves in order to rear their first young, queens of the ponerine pachycondyla 'inversa' forage for food. in founding associations, only one queen specializes in this risky task. here we show that the division of labour is strongly affected by aggressive interactions between cofounding queens: the dominant remains in the ... | 2000 | 12233769 |
| the role of ants, especially the fire ant, solenopsis geminata (hymenoptera: formicidae), in the biological control of tropical upland rice pests. | predatory ants are omnipresent year-round in upland (dryland) rice fields in the philippines. at least 14 species were identified of which the very aggressive solenopsis geminata (fabricius) and also tapinoma sp. nr indicum forel usually predominated. some highly aggressive species, notably pheidolegetonspp. and bothriomyrmex dalyi forel were localized. solenopsis geminata flourished within many fields, not only during the crop season but also throughout dry season fallows where they remained ag ... | 2002 | 12241568 |
| sites of toxicity of specific photooxidation products of anthracene to higher plants: inhibition of photosynthetic activity and electron transport in lemna gibba l. g-3 (duckweed). | sites of toxicity of polycyclic aromatic hydrocarbons (pahs) were examined to determine if inhibition of photosynthetic activity could be correlated to whole-organism toxicity. the inhibition of photosynthesis was observed by detecting the induction kinetics of endogenous chlorophyll a (chl a) fluorescence. anthracene (ant) photooxidation products were applied to the aquatic higher plant lemna gibba l. g-3 at concentrations ranging from 0.01 to 10 ppm. the impact on chl a fluorescence was found ... | 2002 | 12242677 |
| natural enemies of coelomera lanio (coleoptera: chrysomelidae) in the region of viçosa, minas gerais, brazil. | coelomera lanio (coleoptera: chrysomelidae) is the most important defoliator of cecropia trees. natural enemies of c. lanio collected in the region of viçosa, state of minas gerais, brazil were identified on field observations in a forest fragment and on laboratory analyses. individuals of c. lanio were not found on cecropia pachystachya trees colonized by azteca mülleri (hymenoptera: formicidae). the majority of the egg masses of c. lanio collected in the field were found to be parasitised by a ... | 2002 | 12298235 |
| "devil's gardens" in the ecuadorian amazon--association of the allelopathic tree duroia hirsuta (rubiaceae) and its "gentle" ants. | the relationship between the myrmecophytic tree duroia hirsuta (rubiaceae) and its associated, minute, non-aggressive myrmelachista sp. (formicinae) ants is poorly investigated, even though the small understory tree is surrounded by a conspicuos zone almost devoid of vegetation. as to the cause of these barely vegetated "devil's gardens", two alternative interpretations exist in the literature: the pruning activity of ants and allelopathy. we investigated the mutualistic duroia-myrmelachista sys ... | 2002 | 12298256 |
| extreme genetic differences between queens and workers in hybridizing pogonomyrmex harvester ants. | the process of reproductive caste determination in eusocial insect colonies is generally understood to be mediated by environmental, rather than genetic factors. we present data demonstrating unexpected genetic differences between reproductive castes in a variant of the rough harvester ant, pogonomyrmex rugosus var. fuscatus. across multiple loci, queens were consistently more homozygous than expected, while workers were more heterozygous. adult colony queens were divided into two highly diverge ... | 2002 | 12350248 |
| blending in with the crowd: social parasites integrate into their host colonies using a flexible chemical signature. | social parasites are able to exploit their host's communication code and achieve social integration. for colony foundation, a newly mated slave-making ant queen must usurp a host colony. the parasite's brood is cared for by the hosts and newly eclosed slave-making workers integrate to form a mixed ant colony. to elucidate the social integration strategy of the slave-making workers, polyergus rufescens, behavioural and chemical analyses were carried out. cocoons of p. rufescens were introduced in ... | 2002 | 12350253 |