| patch sampling behaviour and future foraging expectations in argentine ants, linepithema humile | nests of argentine ants, l. humile, were exposed to pairs of foraging patches of varying quality. these patches varied from never having food to having food for 4 h every day. after 15 days, colonies were allowed an added access to a new patch. the new patch, however, never contained food. the sampling behaviour of nests towards the initial patches and the new patch suggested that the nests were using a sampling rule based on maximizing net benefits of finding food minus the cost of sampling. th ... | 1998 | 9514665 |
| mechanisms of dispersed central-place foraging in polydomous colonies of the argentine ant. | many species of ants occupy multiple nests, a condition known as polydomy. because of their decentralized structure, polydomous colonies may be removed from some of the constraints associated with classic central-place foraging. we used laboratory and field experiments to assess the mechanisms involved in dispersed central-place foraging in polydomous colonies of the argentine ant linepithema humile, a widespread invasive species. both in the laboratory and in the field, argentine ants establish ... | 2000 | 10675266 |
| reduced genetic variation and the success of an invasive species. | despite the severe ecological and economic damage caused by introduced species, factors that allow invaders to become successful often remain elusive. of invasive taxa, ants are among the most widespread and harmful. highly invasive ants are often unicolonial, forming supercolonies in which workers and queens mix freely among physically separate nests. by reducing costs associated with territoriality, unicolonial species can attain high worker densities, allowing them to achieve interspecific do ... | 2000 | 10811892 |
| oral toxicity of abamectin, boric acid, fipronil, and hydramethylnon to laboratory colonies of argentine ants (hymenoptera: formicidae). | comprehensive laboratory baiting studies with the 4 insecticides abamectin, boric acid, fipronil, and hydramethylnon were conducted against argentine ant, linepithema humile (mayr). serial dilutions of each insecticide prepared in a 25% sucrose solution were provided for 24 h or 14 d to groups of workers and queens. sucrose-water baits containing 1 x 10(-5)% fipronil and 0.1% hydramethylnon provided complete mortality of l. humile workers baited for 24 h. baits containing 1 x 10(-4) and 1 x 10(- ... | 2000 | 10902342 |
| toxicity and repellency of borate-sucrose water baits to argentine ants (hymenoptera: formicidae). | the oral toxicity of boron compounds to the argentine ant, linepithema humile (mayr), was evaluated in laboratory tests. the ants were provided 25% sucrose water containing 0.5 and 1% boric acid, disodium octaborate tetrahydrate, and borax. lethal times of these solutions were a function of the concentration of boron. in field tests, the ants showed no discrimination between disodium octaborate tetrahydrate and boric acid. there was a significant reduction in consumption of sucrose water with > ... | 2000 | 10985039 |
| "you are what you eat": diet modifies cuticular hydrocarbons and nestmate recognition in the argentine ant, linepithema humile. | nestmate recognition plays a key role in the behavior and evolution of social insects. we demonstrated that hydrocarbons are the chemical cues used in argentine ant, linepithema humile, nestmate recognition, and that these hydrocarbons can be acquired from insect prey. consequently, argentine ant cuticular hydrocarbon patterns reveal the same hydrocarbons present in their diet. diet alters both the recognition cues present on the cuticular surface and the response of nestmates to this new colony ... | 2000 | 11091966 |
| patterns of spread in biological invasions dominated by long-distance jump dispersal: insights from argentine ants. | invading organisms may spread through local movements (giving rise to a diffusion-like process) and by long-distance jumps, which are often human-mediated. the local spread of invading organisms has been fit with varying success to models that couple local population growth with diffusive spread, but to date no quantitative estimates exist for the relative importance of local dispersal relative to human-mediated long-distance jumps. using a combination of literature review, museum records, and p ... | 2001 | 11158600 |
| colony disassociation following diet partitioning in a unicolonial ant. | discriminating nestmates from alien conspecifics via chemical cues is recognized as a critical element in maintaining the integrity of insect societies. we determined, in laboratory experiments, that nestmate recognition in an introduced population of the argentine ant, linepithema humile, is modified by hydrocarbons acquired from insect prey, and that workers from spatially isolated colony fragments, each provided with prey that possessed distinct cuticular hydrocarbons, displayed aggressive be ... | 2001 | 11320891 |
| acceptance and intake of gel and liquid sucrose compositions by the argentine ant (hymenoptera: formicidae). | liquids and gels are common delivery forms used in commercial ant baits, but the relative effectiveness of each is unknown. we compared the feeding responses of the argentine ant, linepithema humile (mayr), to liquid and gel compositions of sucrose. in choice assays, more workers were counted on gel than liquid; however, substantially more liquid was consumed. because workers could stand on the gel, more workers could feed simultaneously on the gel. the feeding bouts of individual workers, howev ... | 2001 | 11332847 |
| population genetics and colony structure of the argentine ant (linepithema humile) in its native and introduced ranges. | introduced species often possess low levels of genetic diversity relative to source populations as a consequence of the small population sizes associated with founder events. additionally, native and introduced populations of the same species can possess divergent genetic structuring at both large and small geographic scales. thus, genetic systems that have evolved in the context of high diversity may function quite differently in genetically homogeneous introduced populations. here we conduct a ... | 2001 | 11430657 |
| hydrocarbon-released nestmate aggression in the argentine ant, linepithema humile, following encounters with insect prey. | argentine ants, linepithema humile, were attacked by their nestmates following contact with a particular prey item, the brown-banded cockroach, supella longipalpa. contact with prey, as brief as 2 min, provoked nestmate aggression. argentine ants contaminated with hydrocarbons extracted from s. longipalpa also released nestmate aggression behavior similar to that released by the whole prey item, confirming the involvement of hydrocarbons. in contrast to s. longipalpa, little or no nestmate aggre ... | 2001 | 11435142 |
| relationships among native and introduced populations of the argentine ant (linepithema humile) and the source of introduced populations. | the argentine ant (linepithema humile) is a damaging invasive species that has become established in many mediterranean-type ecosystems worldwide. to identify likely sources of introduced populations we examined the relationships among native linepithema populations from argentina and brazil and introduced populations of l. humile using mitochondrial cytochrome b sequence data and nuclear microsatellite allele frequencies. the mitochondrial phylogeny revealed that the populations in brazil were ... | 2001 | 11555258 |
| consequences of a biological invasion reveal the importance of mutualism for plant communities. | seed-dispersal mutualisms have a fundamental role in regenerating natural communities. interest in the importance of seed dispersal to plant communities has been heightened by worldwide declines in animal dispersers. one view, the 'keystone mutualist hypothesis', predicts that these human-caused losses will trigger a cascade of linked extinctions throughout the community. implicitly, this view holds that mutualisms, such as seed dispersal, are crucial ecological interactions that maintain the st ... | 2001 | 11675787 |
| 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 |
| 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 |
| 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 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 |
| 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 |
| protein that makes sense in the argentine ant. | with a protein-based approach, we have identified and cloned the cdna encoding a chemosensory protein (lhumcsp) in the argentine ant, linepithema humile. the open reading frame of the cloned cdna encoded a signal peptide (20 residues), and a mature protein (pi 4.62) of 106 amino acid residues. the calculated molecular mass (12,453 da) was in agreement with the molecular mass measured by on-line chromatography-electrospray ionization mass spectrometry (12,448 da), given the formation of two disul ... | 2002 | 12451452 |
| 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 |
| determining the foraging range and origin of resurgence after treatment of argentine ant (hymenoptera: formicidae) in urban areas. | the foraging range and distribution of argentine ant, linepithema humile (mayr), colonies in urban areas of southern california extended at least 61 m (200 feet) from feeding stations and structures. ants were fed at 25% sucrose feeding stations containing 0.01% fluorescent brighter (fb28). within 14 d, from 77-90% of the ants sampled next to the feeding stations were positive for fb28. the percentage of ants with fb28 declined gradually to approximately 55% 61 m away from the feeding station. t ... | 2003 | 12852625 |
| effect of aromatic cedar mulch on argentine ant (hymenoptera: formicidae) foraging activity and nest establishment. | in the laboratory, argentine ant, linepithema humile (mayr), mortality was positively correlated to the length of an aromatic cedar mulch section that had to be crossed before food could be reached. when ants could access food without crossing the mulch, mortality was not correlated to mulch section length. in the field, argentine ants showed a tendency to avoid aromatic cedar mulch as a nesting substrate. in plant beds alongside buildings the number of ant nests (pockets containing brood) found ... | 2003 | 12852626 |
| retrieval of granular bait by the argentine ant (hymenoptera: formicidae): effect of clumped versus scattered dispersion patterns. | argentine ants, linepithema humile (mayr), use mass recruitment foraging, with clumped prey items being retrieved more efficiently than dispersed prey. however, in prior field experiments, granular baits, whether dispensed in containers or broadly scattered, had a similar impact on argentine ant populations. in laboratory experiments, granular insecticide bait was encountered faster by argentine ant workers and more granules were initially returned to the colony when the granules were scattered ... | 2003 | 12852629 |
| colony-structure variation and interspecific competitive ability in the invasive argentine ant. | the success of some invasive species may depend on phenotypic changes that occur following introduction. in argentine ants (linepithema humile) introduced populations typically lack intraspecific aggression, but native populations display such behavior commonly. we employ three approaches to examine how this behavioral shift might influence interspecific competitive ability. in a laboratory experiment, we reared colonies of forelius mccooki with pairs of argentine ant colonies that either did or ... | 2004 | 14566557 |
| the distribution and evolutionary history of wolbachia infection in native and introduced populations of the invasive argentine ant (linepithema humile). | wolbachia pipientis is a maternally transmitted bacterium that often alters the life history of its insect host to maximize transmission to subsequent generations. here we report on the frequency and distribution of wolbachia infection in a widespread invasive species, the argentine ant (linepithema humile). we screened 1175 individual argentine ants from 89 nests on five continents and several islands, including numerous locations in both the native (south american) and introduced ranges. we de ... | 2003 | 14629385 |
| argentine ant (hymenoptera: formicidae) trail pheromone enhances consumption of liquid sucrose solution. | we investigated whether the argentine ant, linepithema humile (mayr), trail pheromone, z9-16:ald, could enhance recruitment to and consumption of liquid sucrose solutions. all tests were done as paired comparisons with a 10% sucrose solution as food. in the laboratory, mixing 20 microl of a 10-microg/ml solution of the pheromone with 50 microl of the 10% sucrose solution increased the number of ants feeding by >150%. in a field test, we combined the trail pheromone with a 10% sucrose solution in ... | 2000 | 14658521 |
| ovarian activity correlates with extreme changes in cuticular hydrocarbon profile in the highly polygynous ant, linepithema humile. | in social insects, cuticular hydrocarbons of adults may vary with ovarian activity. such variations are suggested to function in the regulation of reproduction within colonies. the modification of the ch profile with ovarian activity is usually interpreted as a signal of fertility causing workers to refrain from reproducing in the presence of the queen. we examined the effect of ovarian activity on the ch profiles in the argentine ant linepithema humile, a species where workers lack ovaries and ... | 2004 | 15234619 |
| the diminutive supercolony: the argentine ants of the southeastern united states. | native to argentina and brazil, the argentine ant (linepithema humile) is an invasive species that has become established on six continents and many oceanic islands. in several parts of its introduced range, including the western united states, southern europe and chile, the argentine ant is unicolonial, forming extensive supercolonies. we examined population genetic structure and intercolony aggression in two regions of the introduced range of this species in the united states: california and t ... | 2004 | 15245397 |
| delayed toxicity as a critical factor in the efficacy of aqueous baits for controlling argentine ants (hymenoptera: formicidae). | boric acid, imidacloprid, and thiamethoxam in sucrose aqueous baits had different delayed toxicities to worker argentine ants, linepithema humile (mayr). the concentrations required to produce an lt50 (time required to produce 50% mortality) within 1-4 d were 3.63-0.55% boric acid, 9.2 x 10(-3) to 7.1 x 10(-4)% imidacloprid, and 3 x 10(-4) to 2 x 10(-5)% thiamethoxam. the three toxicants were not repellent. other laboratory trials showed that 1% boric acid, 5 x 10(-4) to 5 x 10(-3)% imidacloprid ... | 2004 | 15279286 |
| geographical potential of argentine ants (linepithema humile mayr) in the face of global climate change. | determining the spread and potential geographical distribution of invasive species is integral to making invasion biology a predictive science. we assembled a dataset of over 1000 occurrences of the argentine ant (linepithema humile), one of the world's worst invasive alien species. native to central south america, argentine ants are now found in many mediterranean and subtropical climates around the world. we used this dataset to assess the species' potential geographical and ecological distrib ... | 2004 | 15615677 |
| multilevel genetic analyses of two european supercolonies of the argentine ant, linepithema humile. | some ants have an extraordinary unicolonial social organization, whereby individuals mix freely among physically separated nests. recently, it was shown that the european population of linepithema humile consisted of two enormous unicolonial supercolonies. workers of the same supercolony are never aggressive to each other. in contrast, aggressiveness is invariably high between workers from different supercolonies. here we investigated whether gene flow occurs between two supercolonies. we identi ... | 2005 | 15660948 |
| loss of wolbachia infection during colonisation in the invasive argentine ant linepithema humile. | wolbachia are maternally inherited bacteria, which are very common in arthropods and nematodes. wolbachia infection may affect host reproduction through feminisation, parthenogenesis, male-killing, cytoplasmic incompatibility and increased fecundity. previous studies showing discrepancies between the phylogenies of wolbachia and its arthropod hosts indicate that infection is frequently lost, but the causes of symbiont extinction have so far remained elusive. here, we report data showing that col ... | 2005 | 15674380 |
| effects of interspecific competition between two urban ant species, linepithema humile and monomorium minimum, on toxic bait performance. | we evaluated the effects of interspecific competition on ant bait performance with two urban pest ants, the argentine ant, linepithema humile (mayr), and the little black ant, monomorium minimum (buckley). in a laboratory study, the impact of a solid sulfluramid bait on m. minimum was diminished when l. humile were present, whereas the presence of m. minimum reduced the performance of a liquid fipronil bait against l. humile. argentine ants were not adversely affected by sulfluramid bait at any ... | 2005 | 15889743 |
| diet-related modification of cuticular hydrocarbon profiles of the argentine ant, linepithema humile, diminishes intercolony aggression. | territorial boundaries between conspecific social insect colonies are maintained through a highly developed nestmate recognition system modulated by heritable and, in some instances, nonheritable cues. argentine ants, linepithema humile, use both genetic and environmentally derived cues to discriminate nestmates from nonnestmates. we explored the possibility that intraspecific aggression in the argentine ant might diminish when colonies shared a common diet. after segregating recently field-coll ... | 2005 | 16124254 |
| respiratory and cuticular water loss in insects with continuous gas exchange: comparison across five ant species. | respiratory water loss (rwl) in insects showing continuous emission of co(2) is poorly studied because few methodologies can measure it. comparisons of rwl between insects showing continuous and discontinuous gas exchange cycles (dgc) are therefore difficult. we used two recently developed methodologies (the hyperoxic switch and correlation between water-loss and co(2) emission rates) to compare cuticular permeabilities and rates of rwl in five species of ants, the argentine ant (linepithema hum ... | 2005 | 16154585 |
| invasive argentine ants (linepithema humile) do not replace native ants as seed dispersers of dendromecon rigida (papaveraceae) in california, usa. | we investigated the indirect effects of argentine ant (linepithema humile) invasions on patterns of seed dispersal and predation in the myrmecochorous tree poppy dendromecon rigida in coastal san diego county, california. significantly more seeds were removed from ant-accessible seed stations at sites numerically dominated by a common harvester ant (pogonomyrmex subnitidus), a native disperser of these seeds and a species sensitive to displacement by l. humile, than from those stations at sites ... | 2003 | 16228256 |
| response of argentine ants and red imported fire ants to permethrin-impregnated plastic strips: foraging rates, colonization of potted soil, and differential mortality. | this study investigated the effects of the permethrin-impregnated plastic on ant mortality and foraging rates, and tested its potential for preventing ants from colonizing potted soil. direct exposure to the plastic for as short as 1 min caused significant mortality of both red imported fire ants, solenopsis invicta buren, and argentine ants, linepithema humile (mayr); however, red imported fire ants were more susceptible than argentine ants. knockdown of virtually all ants initially occurred wi ... | 2005 | 16539136 |
| abiotic factors control invasion by argentine ants at the community scale. | 1. a prominent and unresolved question in ecology concerns why communities differ in their susceptibility to invasion. while studies often emphasize biotic resistance, it is less widely appreciated how the physical environment affects community vulnerability to invasion. 2. in this study we performed field experiments to test how abiotic variation directly and indirectly influences the extent to which linepithema humile mayr (argentine ants) invade seasonally dry environments in southern califor ... | 2006 | 16637990 |
| native supercolonies of unrelated individuals in the invasive argentine ant. | kinship among group members has long been recognized as a main factor promoting the evolution of sociality and reproductive altruism, yet 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 dominance of these ants, but also an evolutionary paradox because relatedness between nestmates is effectively zero. recently, it ... | 2006 | 16739459 |
| trap-mulching argentine ants. | argentine ant, linepithema humile (mayr), management is constrained, in large part, by polydomy where nestmates are distributed extensively across urban landscapes, particularly within mulch. management with trap-mulching is a novel approach derived from trap-cropping where ants are repelled from a broad domain of nest sites to smaller defined areas, which are subsequently treated with insecticide. this concept was field-tested with mulch surrounding ornamental trees replaced with a narrow band ... | 2006 | 17066809 |
| niche differentiation and fine-scale projections for argentine ants based on remotely sensed data. | modeling ecological niches of species is a promising approach for predicting the geographic potential of invasive species in new environments. argentine ants (linepithema humile) rank among the most successful invasive species: native to south america, they have invaded broad areas worldwide. despite their widespread success, little is known about what makes an area susceptible--or not--to invasion. here, we use a genetic algorithm approach to ecological niche modeling based on high-resolution r ... | 2006 | 17069375 |
| when supercolonies collide: territorial aggression in an invasive and unicolonial social insect. | some species of ants possess an unusual form of social organization in which aggression among nests is absent. this type of social organization, called unicoloniality, has been studied in only a handful of species and its evolutionary origins remain unclear. to date, no study has examined behavioural and genetic patterns at points of contact between the massive supercolonies that characterize unicoloniality. since interactions at territory boundaries influence the costs of aggression and the lik ... | 2006 | 17107467 |
| structural complexity of chemical recognition cues affects the perception of group membership in the ants linephithema humile and aphaenogaster cockerelli. | hydrocarbon profiles on the cuticle of social insects act as multi-component recognition cues used to identify membership in a species, a colony or, within colonies, cues about its reproductive status or task group. to examine the role of structural complexity in ant hydrocarbon recognition cues, we studied the species recognition response of two ant species, linepithema humile and aphaenogaster cockerelli, and the recognition of conspecifics by l. humile. the cuticular hydrocarbons of ants are ... | 2007 | 17297148 |
| intercolony aggression within and among local populations of the invasive ant, myrmica rubra (hymenoptera: formicidae), in coastal maine. | myrmica rubra l. was introduced into new england in the early 20th century, and at present, has a patchy distribution in parts of northeastern north america, including records from 31 communities in maine. m. rubra is highly polygynous, and colonies reproduce vegetatively, forming dense local populations where conditions are favorable. using mobile nests and baited arenas in a series of field aggression bioassays, we tested patterns of internest tolerance within and among local populations on mt ... | 2007 | 17349123 |
| aggressive interactions between solenopsis invicta and linepithema humile (hymenoptera: formicidae) under laboratory conditions. | the argentine ant, linepithema humile (mayr), and the red imported fire ant, solenopsis invicta buren, are natural agonists in their country of origin. since the first report of l. humile in california in 1907 its range expanded statewide, displacing native ant species wherever it spread. since the discovery of established populations of s. invicta in southern california in 1998, it has been restricted to discrete areas of southern california. however, as these discrete populations expand, they ... | 2007 | 17370822 |
| an experimental study of competition between fire ants and argentine ants in their native range. | an understanding of why introduced species achieve ecological success in novel environments often requires information about the factors that limit the abundance of these taxa in their native ranges. although numerous recent studies have evaluated the importance of natural enemies in this context, relatively few have examined how ecological success may result from differences in the magnitude of interference competition between communities in the native and introduced ranges of nonnative species ... | 2007 | 17489455 |
| a mutualism with a native membracid facilitates pollinator displacement by argentine ants. | the loss of biodiversity and associated ecosystem services are major threats posed by the spread of alien invasive species. invasive ants are frequently associated with declines in the diversity of ground-dwelling arthropods but also may affect plants through their attraction to floral nectar and tending of hemipterans. protea nitida is a tree native to the south african fynbos that hosts a native membracid, beaufortiana sp., which is tended by ants. here i compare argentine ants (linepithema hu ... | 2007 | 17824431 |
| the argentine ant: challenges in managing an invasive unicolonial pest. | the argentine ant, linepithema humile, has invaded urban, agricultural, and natural habitats worldwide, causing economic damage and disrupting ecosystem processes. introduced populations of l. humile and those of many other invasive ants tend to be unicolonial, forming expansive, multiqueened supercolonies that dominate native ant communities and challenge control practices in managed habitats. argentine ant management typically entails the application of residual insecticide liquids, granules, ... | 2008 | 17877449 |
| linking nutrition and behavioural dominance: carbohydrate scarcity limits aggression and activity in argentine ants. | predicting the outcome of competitive interactions is a fundamental goal in ecology. ecological stoichiometry, which relates nutrient balance to ecological processes, provides a framework for identifying mechanistic links among macronutrient availability, nutritional physiology and competitive performance. because carbohydrates serve as a principal metabolic fuel, carbohydrate scarcity may impinge upon behaviours affecting competitive dominance (e.g. aggression, activity) to a greater extent tha ... | 2007 | 17878138 |
| effect of temperature on the oviposition rate of argentine ant queens (linepithema humile mayr) under monogynous and polygynous experimental conditions. | data concerning the influence of temperature on a species' physiological parameters can be a useful tool for predicting its potential distribution range, but in the case of the argentine ant, data based on its physiological needs are too scarce and incomplete to make accurate predictions of this type. in the present study, we offer new and complete data concerning the argentine ant queen's oviposition rate under a wide range of temperatures in the laboratory. we analyzed the oviposition rate of ... | 2008 | 17981292 |
| rainfall facilitates the spread, and time alters the impact, of the invasive argentine ant. | climate change may exacerbate invasions by making conditions more favorable to introduced species relative to native species. here we used data obtained during a long-term biannual survey of the distribution of ant species in a 481-ha preserve in northern california to assess the influence of interannual variation in rainfall on the spread of invasive argentine ants, linepithema humile, and the displacement of native ant species. since the survey began in 1993, argentine ants have expanded their ... | 2008 | 18004595 |
| trophic ecology of invasive argentine ants in their native and introduced ranges. | although the ecological effects of invasions often become obvious soon after introduced species become established, more gradual effects may take years to manifest and can thus require long-term data for quantification. we analyzed an 8-year record of stable isotope data on argentine ants (linepithema humile) from southern california to infer how the trophic position of this widespread invasive species changes over time as native ant species are displaced. we couple this longitudinal analysis wi ... | 2007 | 18093925 |
| biotic and abiotic controls of argentine ant invasion success at local and landscape scales. | although the ecological success of introduced species hinges on biotic interactions and physical conditions, few experimental studies--especially on animals--have simultaneously investigated the relative importance of both types of factors. the lack of such research may stem from the common assumption that native and introduced species exhibit similar environmental tolerances. here we combine experimental and spatial modeling approaches (1) to determine the relative importance of biotic and abio ... | 2007 | 18229850 |
| ant communities (hymenoptera: formicidae) in an urban ecosystem near the atlantic rainforest. | the relationships between an urban ecosystem located near the atlantic rainforest in southeastern brazil and ant communities were studied with the objective of quantifying the ant richness and abundance in the household environment and its surroundings. eighty residences were sampled, where 58 species and 28 genera pertaining to 7 sub-families were found to be present. inside the residences, the species richness was found to be lower (26), although the abundance was greater (10,670), with the wa ... | 2007 | 18278314 |
| foraging activity and dietary spectrum of the argentine ant (hymenoptera: formicidae) in invaded natural areas of the northeast iberian peninsula. | we analyzed the foraging activity and the dietary spectrum of the argentine ant (linepithema humile mayr) and select native ants on cork oaks from mediterranean open cork oak (quercus suber) secondary forests. the study areas included invaded and noninvaded zones in close proximity. the argentine ant's daily foraging activity was correlated to the abiotic factors studied, whereas the seasonal foraging activity was related not only to the variations in the average air temperature, but also to the ... | 2007 | 18284742 |
| commercial agrochemical applications in vineyards do not influence ant communities. | ants have been widely used as bioindicators for various terrestrial monitoring and assessment programs but are seldom considered in evaluation of nontarget pesticide effect. much chemical assessment has been biased toward laboratory and bioassay testing for control of specific pest ant species. several field studies that did explore the nontarget impacts of pesticides on ants have reported contradictory findings. to address the impact of chemical applications on ants, we tested the response of e ... | 2007 | 18284765 |
| improving liquid bait programs for argentine ant control: bait station density. | argentine ants, linepithema humile (mayr), have a positive effect on populations of mealybugs (pseudococcus spp.) in california vineyards. previous studies have shown reductions in both ant activity and mealybug numbers after liquid ant baits were deployed in vineyards at densities of 85-620 bait stations/ha. however, bait station densities may need to be <85 bait stations/ha before bait-based strategies for ant control are economically comparable to spray-based insecticide treatments-a conditio ... | 2007 | 18284776 |
| the evolution of genome size in ants. | despite the economic and ecological importance of ants, genomic tools for this family (formicidae) remain woefully scarce. knowledge of genome size, for example, is a useful and necessary prerequisite for the development of many genomic resources, yet it has been reported for only one ant species (solenopsis invicta), and the two published estimates for this species differ by 146.7 mb (0.15 pg). | 2008 | 18302783 |
| ecological dominance of the red imported fire ant, solenopsis invicta, in its native range. | despite the widespread impacts invasive species can have in introduced populations, little is known about competitive mechanisms and dominance hierarchies between invaders and similar taxa in their native range. this study examines interactions between the red imported fire ant, solenopsis invicta, and other above-ground foraging ants in two habitats in northeastern argentina. a combination of pitfall traps and baits was used to characterize the ant communities, their dominance relationships, an ... | 2008 | 18305962 |
| genetics and behavior of a colonizing species: the invasive argentine ant. | baker and stebbins's 1965 book the genetics of colonizing species aimed to draw together scientists from a variety of disciplines to provide a conceptual framework for the study of species introductions. a goal of their volume was to examine how studies on biological invasions could be used to provide insight into basic research questions as well as to develop practical strategies for control. in this article, we attempt to follow the goals of baker and stebbins by reviewing work on the genetics ... | 2008 | 18554146 |
| detrimental effects of highly efficient interference competition: invasive argentine ants outcompete native ants at toxic baits. | the argentine ant (linepithema humile) is an invasive species that disrupts the balance of natural ecosystems by displacing indigenous ant species throughout its introduced range. previous studies that examined the mechanisms by which argentine ants attain ecological dominance showed that superior interference and exploitation competition are key to the successful displacement of native ant species. the objective of this research was to test the hypothesis that effective interference competition ... | 2008 | 18559180 |
| testing baits to control argentine ants (hymenoptera: formicidae) in vineyards. | liquid baits were evaluated for control of the argentine ant, linepithema humile (mayr) (hymenoptera: formicidae), and associated mealybug and soft scale pests in california vineyards. in 2003, liquid baits with small doses ofimidacloprid, boric acid, or thiamethoxam dissolved in 25% sucrose water resulted in lower ant and mealybug densities and fruit damage, compared with an untreated control. similar treatments in a soft scale-infested vineyard showed only a reduction of ant density and fruit ... | 2008 | 18613568 |
| occurrence of antennal glands in ants. | a previous report of the discovery of exocrine glands in the antennal club of queens and workers of solenopsis invicta buren, 1972 left open the question of the extent to which similar glands occur in the formicidae family. we wanted to know if these antennal glands are unique to solenopsis, or they are found in a wider taxonomic group. using scanning electron microscopy, we examined the antennae of 41 ant species. presence of the antennal glands was indicated by a characteristic circumferential ... | 2008 | 18655135 |
| horizontal transfer of insecticides in laboratory colonies of the argentine ant (hymenoptera: formicidae). | five insecticides used by urban pest management professionals for ant control and three experimental insecticides were tested to determine whether these insecticides were horizontally transferred among individuals in colonies of argentine ants, linepithema humile (mayr) (hymenoptera: formicidae). ants were exposed to insecticide-treated sand for 1 min and then placed in a colony of untreated ants. ants exposed to 20 and 40 ppm fipronil readily transferred the insecticide to other individuals in ... | 2008 | 18767753 |
| new mutualism for old: indirect disruption and direct facilitation of seed dispersal following argentine ant invasion. | the indirect effects of biological invasions on native communities are poorly understood. disruption of native ant communities following invasion by the argentine ant (linepithema humile) is widely reported to lead indirectly to the near complete collapse of seed dispersal services. in coastal scrub in southeastern australia, we examined seed dispersal and handling of two native and two invasive alien plant species at argentine ant-invaded or -uninvaded sites. the argentine ant virtually elimina ... | 2009 | 18941793 |
| pheromone disruption of argentine ant trail integrity. | disruption of argentine ant trail following and reduced ability to forage (measured by bait location success) was achieved after presentation of an oversupply of trail pheromone, (z)-9-hexadecenal. experiments tested single pheromone point sources and dispersion of a formulation in small field plots. ant walking behavior was recorded and digitized by using video tracking, before and after presentation of trail pheromone. ants showed changes in three parameters within seconds of treatment: (1) an ... | 2008 | 19034574 |
| dynamics and genetic structure of argentine ant supercolonies in their native range. | some introduced ant populations have an extraordinary social organization, called unicoloniality, whereby individuals mix freely within large supercolonies. we investigated whether this mode of social organization also exists in native populations of the argentine ant linepithema humile. behavioral analyses revealed the presence of 11 supercolonies (width 1 to 515 m) over a 3-km transect. as in the introduced range, there was always strong aggression between but never within supercolonies. the g ... | 2009 | 19154388 |
| global-scale analyses of chemical ecology and population genetics in the invasive argentine ant. | ants are some of the most abundant and ecologically successful terrestrial organisms, and invasive ants rank among the most damaging invasive species. the argentine ant is a particularly well-studied invader, in part because of the extreme social structure of introduced populations, known as unicoloniality. unicolonial ants form geographically vast supercolonies, within which territorial behaviour and intraspecific aggression are absent. because the extreme social structure of introduced populat ... | 2009 | 19207262 |
| ant community structure in citrus orchards in the mediterranean basin: impoverishment as a consequence of habitat homogeneity. | this study analyzes the structure and composition of ant communities in citrus orchards in catalonia (northeast spain) and compares them with the ant fauna found in natural communities of the region. in the citrus orchards considered in this study, the most abundant species were lasius niger and pheidole pallidula, which are behaviorally dominant species. two other dominant species, linepithema humile and tetramorium caespitum, were also abundant, although only in one orchard. species richness a ... | 2009 | 19389279 |
| chemical signals associated with life inhibit necrophoresis in argentine ants. | one of the most conspicuous and stereotyped activities of social insects such as ants and honey bees is necrophoresis, the removal of dead colony members from the nest. previous researchers suggested that decomposition products such as fatty acids trigger necrophoric behavior by ant workers. however, fatty acids elicit both foraging and necrophoric responses, depending on the current nest activities (e.g., feeding or nest maintenance). furthermore, workers often carry even freshly killed workers ... | 2009 | 19416815 |
| carbohydrate supply limits invasion of natural communities by argentine ants. | the ability of species to invade new habitats is often limited by various biotic and physical factors or interactions between the two. invasive ants, frequently associated with human activities, flourish in disturbed urban and agricultural environments. however, their ability to invade and establish in natural habitats is more variable. this is particularly so for the invasive argentine ant (linepithema humile). while biotic resistance and low soil moisture limits their invasion of natural habit ... | 2009 | 19452171 |
| colony fusion in argentine ants is guided by worker and queen cuticular hydrocarbon profile similarity. | introduced populations of the argentine ant, linepithema humile, have experienced moderate to severe losses of genetic diversity, which may have affected nestmate recognition to various degrees. we hypothesized that cuticular hydrocarbons (chc) serve as nestmate recognition cues, and facilitate colony fusion of unrelated l. humile colonies that share similar chc profiles. in this study, we paired six southeastern u.s. l. humile colonies in a 6-month laboratory fusion assay, and determined if wor ... | 2009 | 19609617 |
| effects of honeydew-producing hemipteran denial on local argentine ant distribution and boric acid bait performance. | the argentine ant is well known for its affinity for honeydew and is often associated with hemipteran outbreaks in agricultural and urban environments. it has been suggested that argentine ants may be controlled by restricting access to honeydew, thereby forcing the ants to move or by encouraging increased liquid toxicant intake. we tested this possible control strategy by restricting argentine ant access to the honeydew-producing terrapin scale within the canopy of red maple trees and monitorin ... | 2009 | 19610434 |
| where and how argentine ant (linepithema humile) spreads in corsica? | the argentine ant, linepithema humile (dolichoderinae), is one of the most widespread invasive ant species in the world. when established in optimal habitat, this species usually excludes most other local ants and can heavily impact other arthropods as well. although argentine ants have been present in southern europe for more than 100 years, they were first noted in corsica, a french mediterranean island, in 1957 in only one urban station. in this study, we aimed to map precisely their geograph ... | 2009 | 19632658 |
| predicting argentine ant spread over the heterogeneous landscape using a spatially explicit stochastic model. | the characteristics of spread for an invasive species should influence how environmental authorities or government agencies respond to an initial incursion. high-resolution predictions of how, where, and the speed at which a newly established invasive population will spread across the surrounding heterogeneous landscape can greatly assist appropriate and timely risk assessments and control decisions. the argentine ant (linepithema humile) is a worldwide invasive species that was inadvertently in ... | 2009 | 19688925 |
| experience influences aggressive behaviour in the argentine ant. | all animals interact with conspecifics during their life, and nearly all also display some form of aggression. an enduring challenge, however, is to understand how the experiences of an individual animal influence its later behaviours. several studies have shown that prior winning experience increases the probability of initiating fights in later encounters. using behavioural assays in the laboratory, we provide evidence that, in argentine ants (linepithema humile), the mere exposure to an oppon ... | 2010 | 19793741 |
| the scent of supercolonies: the discovery, synthesis and behavioural verification of ant colony recognition cues. | ants form highly social and cooperative colonies that compete, and often fight, against other such colonies, both intra- and interspecifically. some invasive ants take sociality to an extreme, forming geographically massive 'supercolonies' across thousands of kilometres. the success of social insects generally, as well as invasive ants in particular, stems from the sophisticated mechanisms used to accurately and precisely distinguish colonymates from non-colonymates. surprisingly, however, the s ... | 2009 | 19863781 |
| threat and management strategies of potentially invasive insects in china. | the global invasive species database, gisd, comprises 27 species of the most significant invasive alien insects in the world (through november, 2005), 6 of which are originally native to china, 11 are established in china, and 10 have a potential invasion threat to china. this paper discusses these species in terms of distribution, harmfulness and dispersal ways, and finds that: (i) information regarding invasive insects in the gisd remains inadequate. such harmful invasive species as opogona sa ... | 2009 | 19911125 |
| [ants (hymenoptera: formicidae) as vectors for bacteria in two hospitals in the municipality of divinópolis, state of minas gerais]. | the presence of ants (hymenoptera: formicidae) in hospital environments may constitute a public health problem, especially since they are mechanical vectors for pathogenic organisms. this study aimed to survey the ant populations and analyze the presence of bacteria associated with them in two medium-sized regional hospitals in the municipality of divinópolis, minas gerais, brazil. specimens were collected every monthly over a six-month period. the following ant species were found: pheidole sp1 ... | 2009 | 19967241 |
| effect of an invasive and native ant on a field population of the black citrus aphid (hemiptera: aphididae). | invasive ants often enter into facultative mutualisms that frequently lead to outbreaks of the hemipteran partner. native ants may also enter into similar mutualisms but often these do not lead to outbreaks. however, field studies comparing the impact of an invasive and native ant on a honeydew-producing hemipteran are lacking. we monitored numerical changes of the black citrus aphid, toxoptera aurantii, tended by adjacent colonies of the invasive argentine ant, linepithema humile, and the endem ... | 2009 | 20021757 |
| activity of bifenthrin, chlorfenapyr, fipronil, and thiamethoxam against argentine ants (hymenoptera: formicidae). | bifenthrin, chlorfenapyr, fipronil, and thiamethoxam were evaluated for activity against the argentine ant, linepithema humile (mayr) (hymenoptera: formicidae). mobility impairment and lethal times were determined after topical treatments. ants were immobilized most quickly by bifenthrin, followed by chlorfenapyr and thiamethoxam. after 2 h, the number of fipronil-treated ants unable to walk out of test arenas did not differ from control ants. median lethal time (lt50) after topical treatment wa ... | 2009 | 20069858 |
| trail pheromone disruption of argentine ant trail formation and foraging. | trail pheromone disruption of invasive ants is a novel tactic that builds on the development of pheromone-based pest management in other insects. argentine ant trail pheromone, (z)-9-hexadecenal, was formulated as a micro-encapsulated sprayable particle and applied against argentine ant populations in 400 m2 field plots in hawai'i volcanoes national park. a widely dispersed point source strategy for trail pheromone disruption was used. traffic rates of ants in bioassays of treated filter paper, ... | 2010 | 20077128 |
| ants as a measure of effectiveness of habitat conservation planning in southern california. | in the united states multispecies habitat conservation plans were meant to be the solution to conflicts between economic development and protection of biological diversity. although now widely applied, questions exist concerning the scientific credibility of the conservation planning process and effectiveness of the plans. we used ants to assess performance of one of the first regional conservation plans developed in the united states, the orange county central-coastal natural community conserva ... | 2010 | 20337686 |
| nutrition and interference competition have interactive effects on the behavior and performance of argentine ants. | food availability often influences competitive outcomes through effects on consumer growth. although it has received less attention, food availability may also affect competition through nutritional effects on behavior. one hypothesis linking nutrition and competition in ants posits that increased access to carbohydrates favors greater investment in worker traits that underlie behavioral dominance. we tested this hypothesis by varying dietary protein:carbohydrate (p:c) ratios and levels of inter ... | 2010 | 20380196 |
| trail pheromone disruption of red imported fire ant. | the fire ant, solenopsis invicta (hymenoptera: formicidae), is considered one of the most aggressive and invasive species in the world. toxic bait systems are used widely for control, but they also affect non-target ant species and cannot be used in sensitive ecosystems such as organic farms and national parks. the fire ant uses recruitment pheromones to organize the retrieval of large food resources back to the colony, with z,e-alpha-farnesene responsible for the orientation of workers along tr ... | 2010 | 20549330 |
| deciphering the chemical basis of nestmate recognition. | social insects maintain colony cohesion by recognizing and, if necessary, discriminating against conspecifics that are not part of the colony. this recognition ability is encoded by a complex mixture of cuticular hydrocarbons (chcs), although it is largely unclear how social insects interpret such a multifaceted signal. chc profiles often contain several series of homologous hydrocarbons, possessing the same methyl branch position but differing in chain length (e.g., 15-methyl-pentatriacontane, ... | 2010 | 20556636 |
| trophic ecology of the invasive argentine ant: spatio-temporal variation in resource assimilation and isotopic enrichment. | studies of food webs often employ stable isotopic approaches to infer trophic position and interaction strength without consideration of spatio-temporal variation in resource assimilation by constituent species. using results from laboratory diet manipulations and monthly sampling of field populations, we illustrate how nitrogen isotopes may be used to quantify spatio-temporal variation in resource assimilation in ants. first, we determined nitrogen enrichment using a controlled laboratory exper ... | 2010 | 20577762 |
| effect of temperature on the development and survival of the argentine ant, linepithema humile. | the influence of temperature on the developmental times and survival of insects can largely determine their distribution. for invasive species, like the argentine ant, linepithema humile mayr (hymenoptera: formicidae), these data are essential for predicting their potential range based on mechanistic models. in the case of this species, such data are too scarce and incomplete to make accurate predictions based on its physiological needs. this research provides comprehensive new data about brood ... | 2010 | 20673121 |
| development of virtual bait stations to control argentine ants (hymenoptera: formicidae) in environmentally sensitive habitats. | a novel bait station referred to as a virtual bait station was developed and tested against field populations of the invasive argentine ant, linepithema humile (mayr) (hymenoptera: formicidae), at white beach, camp pendleton, in oceanside, ca. white beach is a nesting habitat for an endangered seabird, the california least tern (sterna antillarum browni mearns). the beach is heavily infested with argentine ants, one of the threats for the california least tern chicks. conventional pest control s ... | 2010 | 21061977 |
| long-term field trial to control the invasive argentine ant (hymenoptera: formicidae) with synthetic trail pheromone. | previous short-term experiments showed that trail following behavior of the argentine ant, linepithema humile (mayr) (hymenoptera: formicidae), can be disrupted by a high concentration of synthetic trail pheromone component (z)-9-hexadecenal. in this study, a long-term field trial was conducted in 100-m2 plots of house gardens in an urban area of japan to see whether the control effect on argentine ants can be obtained by permeating synthetic trail pheromone from dispensers. the dispensers were ... | 2010 | 21061980 |
| combined effect of hemipteran control and liquid bait on argentine ant populations. | the invasive argentine ant, linepithema humile (mayr), has become a worldwide problem capable of inflicting significant ecological and economic injury on urban, agricultural, and natural environments. the mobility of this pest ant has long been noted, rapidly moving nests to new food resources and then away as resources are depleted. this ant, like many pest ant species, has a special affinity for honeydew excreted by phloem-feeding hemiptera. we investigated the effect of various hemipteran con ... | 2010 | 21061981 |
| [factors influencing the distribution of nests of the argentine ant linepithema humile mayr (hymenoptera: formicidae), in a foothills ecosystem of the central zone of chile]. | the purpose of this research was to demonstrate the dependant relationship between the argentine ant linepithema humile mayr, plant coverage, and human settlements. a method was designed in order to sample the presence of the argentine ant and other ant species that may had influenced l. humile distribution, under different types of vegetation and percentages of plant coverage, taking in consideration the distance from human settlements. eight sample stations were established. four of these stat ... | 2010 | 21120373 |
| optimisation in a natural system: argentine ants solve the towers of hanoi. | natural systems are a source of inspiration for computer algorithms designed to solve optimisation problems. yet most 'nature-inspired' algorithms take only superficial inspiration from biology, and little is known about how real biological systems solve difficult problems. moreover, ant algorithms, neural networks and similar methods are usually applied to static problems, whereas most biological systems have evolved to perform under dynamically changing conditions. we used the towers of hanoi ... | 2011 | 21147968 |
| description of the immatures of linepithema humile mayr (hymenoptera: formicidae). | linepithema humile mayr is an ant species originally native to south america that has been spread accidently throughout the globe through international trade. it is a serious urban and crop pest. despite its economic importance, little is known about the larvae of this species apart from a brief description based on a few specimens. the present investigation is aimed at describing every immature stage of l. humile. three larval instars were determined through the frequency distribution of the ma ... | 2010 | 21157629 |
| relative roles of climatic suitability and anthropogenic influence in determining the pattern of spread in a global invader. | because invasive species threaten the integrity of natural ecosystems, a major goal in ecology is to develop predictive models to determine which species may become widespread and where they may invade. indeed, considerable progress has been made in understanding the factors that influence the local pattern of spread for specific invaders and the factors that are correlated with the number of introduced species that have become established in a given region. however, few studies have examined th ... | 2010 | 21173219 |
| modelling foraging ants in a dynamic and confined environment. | in social insects, the superposition of simple individual behavioral rules leads to the emergence of complex collective patterns and helps solve difficult problems inherent to surviving in hostile habitats. modelling ant colony foraging reveals strategies arising from the insects' self-organization and helps develop of new computational strategies in order to solve complex problems. this paper presents advances in modelling ants' behavior when foraging in a confined and dynamic environment, base ... | 2011 | 21236313 |
| draft genome of the globally widespread and invasive argentine ant (linepithema humile). | ants are some of the most abundant and familiar animals on earth, and they play vital roles in most terrestrial ecosystems. although all ants are eusocial, and display a variety of complex and fascinating behaviors, few genomic resources exist for them. here, we report the draft genome sequence of a particularly widespread and well-studied species, the invasive argentine ant (linepithema humile), which was accomplished using a combination of 454 (roche) and illumina sequencing and community-base ... | 2011 | 21282631 |
| behavioural and chemical evidence for multiple colonisation of the argentine ant, linepithema humile, in the western cape, south africa. | the argentine ant, linepithema humile, is a widespread invasive ant species that has successfully established in nearly all continents across the globe. argentine ants are characterised by a social structure known as unicoloniality, where territorial boundaries between nests are absent and intraspecific aggression is rare. this is particularly pronounced in introduced populations and results in the formation of large and spatially expansive supercolonies. although it is amongst the most well stu ... | 2011 | 21288369 |
| structure and formation of ant transportation networks. | many biological systems use extensive networks for the transport of resources and information. ants are no exception. how do biological systems achieve efficient transportation networks in the absence of centralized control and without global knowledge of the environment? here, we address this question by studying the formation and properties of inter-nest transportation networks in the argentine ant (linepithema humile). we find that the formation of inter-nest networks depends on the number of ... | 2011 | 21288958 |
| workers select mates for queens: a possible mechanism of gene flow restriction between supercolonies of the invasive argentine ant. | some invasive ants form large networks of mutually non-aggressive nests, i.e., supercolonies. the argentine ant linepithema humile forms much larger supercolonies in introduced ranges than in its native range. in both cases, it has been shown that little gene flow occurs between supercolonies of this species, though the mechanism of gene flow restriction is unknown. in this species, queens do not undertake nuptial flight, and males have to travel to foreign nests and cope with workers before gai ... | 2011 | 21424796 |