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1.
Background
Wolbachia are endosymbiotic bacteria that commonly infect numerous arthropods. Despite their broad taxonomic distribution, the transmission patterns of these bacteria within and among host species are not well understood. We sequenced a portion of the wsp gene from the Wolbachia genome infecting 138 individuals from eleven geographically distributed native populations of the fire ant Solenopsis invicta. We then compared these wsp sequence data to patterns of mitochondrial DNA (mtDNA) variation of both infected and uninfected host individuals to infer the transmission patterns of Wolbachia in S. invicta. 相似文献2.
Nest structure in ants is often designed to optimize the colony’s ability to thermoregulate, and this specialization is most
highly developed in mound-building ant species. Solenopsis invicta invest a large amount of energy in building mounds and transporting their brood up and down in their nests as a means of
thermoregulation. Because few ant species build true mounds, we wanted to determine the effectiveness of these mounds in harvesting
solar heat as well as to distinguish what factors (temperature vs. circadian rhythm) govern where fire ants place their brood
in the mound and when they place it. We measured temperature patterns in the mound over several days at different depths and
under different conditions (under direct sunlight or shade), and then conducted a series of field experiments to manipulate
the orientation and time of heating.
On cool mornings in spring or fall, surface temperatures of the mound rise at the fastest rate on the side receiving the most
direct sunlight (usually the south side). This heating causes a temperature gradient through different depths in the mound,
and shows little difference from outside ground temperature at a depth greater than ~40 cm inside the nest. In the morning,
fire ants move their brood up into the mound on the side most directly heated, and when temperatures exceed optimal (~32°C)
they move their brood down the temperature gradient to lower depths in the nest. In addition to this, mound temperature does
not only increase due to direct sunlight, but temperature also increases higher than ground temperatures when the mound is
in the shade due to its low specific heat.
Experiments in which sunlight was mirrored to the normally shaded side of the mound, or when mounds were heated at night,
revealed that S. invicta primarily track temperature patterns and do not rely on behavioral habits or circadian rhythms for the thermoregulatory transport
of their brood. When mounds were shaded, S. invicta brood was evenly distributed directly under the surface of the mound rather than aggregating towards a specific side. The
fire ant mound is important for thermoregulation because, compared to moundless subterranean nests, it absorbs heat more rapidly
both in direct sunlight and shady conditions. Temperature tracking within the nest is key to understanding thermoregulatory
placement of fire ant brood, as well as insight into the production of sexual brood and reproduction.
Received 9 August 2007; revised 31 January 2008; accepted 7 February 2008. 相似文献
3.
Summary Male inhibition of female re-mating is com-mon in many insects. Mating plugs, used by males
to con-trol female re-mating, have been postulated in several ant species. Recent studies of
bumblebees have described re-mating inhibition by male accessory gland secretions. Fire
ants Solenopsis invicta possess accessory glands containing
the same four fatty acids as do the bumblebees. Furthermore it appears that some of these acids
are transferred to the female at mating. Thus, it is possible that single mating of fire ant
females may be enforced by male mating plugs. 相似文献
4.
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, and to evaluate the effect of phorid flies on
the interactions. Twenty-eight ant species coexisted with S. invicta in a gallery forest gap, whereas only ten coexisted with S. invicta in a xerophytic forest grassland. S. invicta was the most numerically dominant species in the richest and complex habitat (gallery forest); however it performed better
as discoverer and dominator in the simpler habitat. S. invicta was active during day and night. In spite of its poor capacity to discover resources, S. invicta showed the highest ecological dominance and the second-best behavioral dominance after Camponotus blandus. S. invicta won 78% of the interactions with other ants, mostly against its most frequent competitor, Pheidole cf. obscurithorax, dominating baits via mass recruitment and chemical aggression. P. cf. obscurithorax was the best food discoverer. S. invicta won 80% of the scarce interactions with Linepithema humile.
Crematogaster quadriformis was one of the fastest foragers and the only ant that won an equal number of contests against S. invicta. The low presence of phorid flies affected the foraging rate of S. invicta, but not the outcome of interspecific interactions. This study revealed that the red imported fire ant ecologically dominated
other terrestrial ants in its native range; however, other species were able to be numerically dominant or co-dominant in
its presence. 相似文献
5.
Michael A. D. Goodisman Karen A. Sankovich Jennifer L. Kovacs 《Biological invasions》2007,9(5):571-584
Social insects are among the most successful and damaging of invasive taxa. We studied spatial and temporal variation in two
traits, colony genetic structure and worker mass, associated with social insect success in the introduced fire ant Solenopsis
invicta. Our aim was to determine if changes in social structure occurred over time and if variation in worker size was related to
worker genotype. We sampled 1139 workers from five multiple-queen S. invicta nests on six dates over a one-year period. The genotypes of workers were determined at ten microsatellite loci and at the
selected locus general protein-9 (Gp-9). We found little evidence for genetic differentiation of workers sampled from distinct nests or from different dates at
the microsatellite loci. However, worker Gp-9 genotype frequencies varied among nests and over time. In addition, worker mass was affected by nest-of-origin, sampling
date, ploidy level, and Gp-9 genotype. Our results suggest that large numbers of queens contribute to the production of workers in introduced S. invicta nests throughout the year. Colony boundaries are semi-permeable, although the among-nest variation in Gp-9 genotype frequencies and worker mass does suggest that boundaries are present. In addition, selection operating on Gp-9 genotype depends on nest environment. Finally, worker mass is affected by both endogenous and exogenous factors in S. invicta. Overall, our data suggests that the key traits of colony social structure and worker size reflect the effects of variable
selection in invasive social insects. 相似文献
6.
Jun Huang Yijuan Xu Ling Zeng Yongyue Lu Guangwen Liang 《Journal of Insect Behavior》2011,24(4):307-316
Solenopsis invicta is an aggressive, destructive and invasive ant. It has a profound impact on the native species in its environment. In this
paper, we studied the effect of S. invicta on the invasive weed Ageratum conyzoides in the field. Using grid sampling and geostatistical analysis, we found that the density of A. conyzoides increased significantly in the presence of S. invicta. Furthermore, the spatial distribution of A. conyzoides was affected by S. invicta. The spatial structure of A. conyzoides emergence was aggregated. Sites where S. invicta was present were described by a Gaussian model, whereas a spatial model was used to describe the sites in the absence of
S. invicta. The range of spatial dependence was 7.07 m for sites with a high density of S. invicta, whereas the spatial dependence was 1.46 m for sites with a low density of S. invicta and 3.14 m for control sites. Semivariogram models based on grid sampling of actual emerging A. conyzoides densities were used to produce contour maps of A. conyzoides densities in the field. 相似文献
7.
Refuges are fundamental to animal ecology as refuge availability affects many levels of biological organization—from the behavior and physiology of individuals to the interspecific dynamics of a community. Although frequently studied in the context of predator–prey interactions, refuges may also mediate interspecific competition between native and invasive taxa given the role of refuges as a valuable resource. Because interspecific interactions (e.g., competition and predation) can be modulated by temporal and biotic (e.g., trophic level) factors, we used a manipulative approach to investigate community-wide refuge-use patterns in the context of two important ecological factors: invasive species and seasonality. We surveyed refuge (artificial cover object) use of ants and vertebrates in a forest community for 2 years, and we systematically suppressed an established invasive species (red imported fire ant, Solenopsis invicta) to examine its impact on community refuge use. Native Camponotus ants appeared to co-exist and share refuges with S. invicta, but we found evidence for a negative effect of S. invicta on vertebrate refuge use that was also influenced by season. Vertebrates were more abundant under refuges undergoing suppression of S. invicta, and they were less abundant under refuges during the fall (the season characterized by the highest occupancy of refuges by S. invicta). Thus, researchers must continue to examine the entire community and to incorporate the effects of season when assessing the impact of invasive species (e.g., at our site, a survey conducted only in the summer or only on native ants would have indicated a negligible effect of S. invicta on community refuge use). 相似文献
8.
Sheldon Plentovich Chris Swenson Neil Reimer Mike Richardson Norman Garon 《Journal of Insect Conservation》2010,14(5):459-465
Invasive ants can cause major disruptions in native ecosystems. Ant eradication methods without significant non-target effects are needed to stop incipient invasions and to aid in ecosystem restoration. Successful ant eradications are rare and there is very little understanding of the effects of ant eradication methods, such as the use of formicides, on non-target species. Here we attempted to control and possibly eradicate the invasive tropical fire ant, Solenopsis geminata, from a small islet using the formicide Maxforce® (active ingredient: hydramethylnon), and to quantify the non-target effects on an almost exclusively alien ground-dwelling arthropod community. S. geminata abundance was reduced and the species was not detected on bait cards for 12 months post-treatment. The abundance of another non-target invasive ant that was primarily detected in pitfall traps, Tetramoruim bicarinatum, declined in pitfall traps following treatment, but seemed to be excluded from bait cards by S. geminata. Total ant abundance did not return to original levels until more than 12 months post-treatment. Populations of alien cockroaches (Order Blattaria) and crickets (Orthoptera: Gryllidae) were negatively affected by the treatment. We conclude that Maxforce® can be used to control small infestations of S. geminata and T. bicarinatum effectively; however we recommend it be used cautiously due to the potential ecological cost to non-target species. Use in areas where infestations are small and isolated will maximize the likelihood of success while minimizing non-target effects. 相似文献
9.
We documented patterns of seasonal abundance and rates of parasitism in introduced populations of Pseudacteon tricuspis Borgmeier, a phorid parasitoid of the red imported fire ant, Solenopsis invicta Buren. Adult P. tricuspis populations were censused at monthly intervals for 1 year at three sites in northern Florida. Censuses were conducted by aspirating phorids attracted to disturbed S. invicta mounds. Pseudacteon tricuspis adults were present in every month at all sites, although abundances varied greatly among sites and over time. The highest densities of flies (up to 453 censused at 10 disturbed S. invicta mounds in 30 min) were observed in November, and changes in abundance over time were positively correlated among sites. Sex ratios were usually male biased. Parasitism rates were evaluated by collecting workers from field colonies and monitoring them in the laboratory for evidence of parasitism. Parasitism rates were very low – always less than 1%. The average parasitism rate per colony over 16 colonies and 2 years was 0.058%. No pupariation occurred within the first 8 days of collection, suggesting parasitism by P. tricuspis induced behavioral changes in parasitized workers that precluded such workers from our collections. If so, true field parasitism rates may be several times higher than measured here, yet still low in an absolute sense. These low parasitism rates can be reconciled with observed adult phorid densities by considering the large number of host ants present at the study sites. 相似文献
10.
Eric J. Caldera Kenneth G. Ross Christopher J. DeHeer D. DeWayne Shoemaker 《Biological invasions》2008,10(8):1457-1479
The ecological and evolutionary dynamics of newly introduced invasive species can best be understood by identifying the source
population(s) from which they originated, as many species vary behaviorally, morphologically, and genetically across their
native landscapes. We attempt to identify the source(s) of the red imported fire ant (Solenopsis invicta) in the southern USA utilizing data from three classes of genetic markers (allozymes, microsatellites, and mitochondrial
DNA sequences) and employing Bayesian clustering simulations, assignment and exclusion tests, and phylogenetic and population
genetic analyses. We conclude that the Mesopotamia flood plain near Formosa, Argentina represents the most probable source
region for introduced S. invicta among the 10 localities sampled across the native South American range. This result confirms previous suspicions that the
source population resides in northern Argentina, while adding further doubts to earlier claims that the Pantanal region of
Brazil is the source area. Several lines of evidence suggest that S. invicta in the southern USA is derived from a single location rather than being the product of multiple invasions from widely separated
source localities. Although finer-scale sampling of northern Argentina and Paraguay combined with the use of additional genetic
markers will be necessary to provide a highly precise source population assignment, our current results are of immediate use
in directing future sampling and focusing ongoing biological control efforts. 相似文献
11.
Li-Chuan Lai Ming-Chung Chiu Chih-Wei Tsai Wen-Jer Wu 《Arthropod-Plant Interactions》2018,12(4):623-632
Solenopsis geminata (F.) is an invasive ant that is widely distributed in weedy areas and agricultural fields in Taiwan. Previous studies have found that S. geminata harvests the seeds of numerous plants. In the present study, we further investigated the composition of harvested seeds in ant nests and seed selection by workers. The seed caches in S. geminata nests sampled in eight areas in Taiwan suggest that the seeds harvested by workers were diverse and belonged to 52 plant species in 17 plant families. Twenty-three species (44%) belong to the family Gramineae, and most of the seeds weighed from 0.02 to 2.29 mg, which might suggest that these are the main seeds harvested by S. geminata from their habitat. Ten common species with similar seed weights were used to compare the seed preferences of workers from two experimental sites. The results suggest that the seed preference was different between the two experimental sites. The seeds of Casuarina equisetifolia showed the most obvious difference in seed removal speed, which might suggest that S. geminata potentially prefers the encountered seed species in the habitat. The various plant species in the ant nests and seed preference suggest that fire ants easily accept newly encountered plant species. As more than half of the plant species (52%) and the total seed number (63%) belonged to exotic species, the role of S. geminata might be negative because it tends to harvest exotic seeds and has a high opportunity to improve the establishment of exotic seedlings. 相似文献
12.
Freder Medina Haiwen Li S. Bradleigh Vinson Craig J. Coates 《Current microbiology》2009,58(5):478-482
In our previous study we isolated 10 bacterial species from fourth-instar larval midguts of the red imported fire ant, Solenopsis invicta. Here we report the genetic transformation and reintroduction of three species (Kluyvera cryocrescens, Serratia marcescens, and isolate 38) into the fire ant host. All three species were transformed with the plasmid vector, pZeoDsRed. High expression
levels of DsRed were observed and the plasmid is maintained in these bacteria at 37°C in the absence of antibiotic selection
for at least 9 days of subculturing. The transformed bacteria were successfully reintroduced into fire ant larvae and survived
in the fire ant gut for at least 7 days. Upon pupal emergence, 7 days after reintroduction, transformed bacteria can still
be isolated, however, most were passed out in the meconium. We further demonstrated that the engineered bacteria could be
spread within the colony by feeding this meconium to naive larvae with the aid of worker fire ants.
Freder Medina and Haiwen Li have contributed equally to this work. 相似文献
13.
14.
Inherent in any biological control program is the risk of nontarget effects. Pseudacteon tricuspisBorgmeier, a parasitoid phorid fly, has been introduced to the United States from South America as a potential biocontrol
agent of the red imported fire ant, Solenopsis invictaBuren. We conducted tests of host specificity on introduced populations of P. tricuspis, which are attracted to alarm pheromones released by their hosts during events such as mound disturbances and interspecific
interactions. We monitored disturbed mounds of S. invicta and its close congener, S. geminata(F.), during the expansion of P. tricuspis across north Florida and after populations had been established for ~3 years. We also tested host acceptance in established
populations of P. tricuspis by offering trays containing S. invicta, S. geminata, and 14 additional ant species representing 12 different non-Solenopsis genera. Although P. tricuspiswas commonly observed to hover over and attempt to oviposit on S. invicta, we never observed any parasitization attempts on any other ant species. As predicted by laboratory tests, released populations
of P. tricuspis appear to be highly host specific and pose no obvious threat to nontarget species. 相似文献
15.
Endosymbiotic bacteria that potentially influence reproduction and other fitness-related traits of their hosts are widespread
in insects and mites and their appeal to researchers’ interest is still increasing. We screened 20 strains of 12 agriculturally
relevant herbivorous and predatory mite species for infection with Wolbachia, Cardinium and Spiroplasma by the use of PCR. The majority of specimens originated from Austria and were field collected or mass-reared. Eight out of
20 strains (40%) tested, representing seven of 12 mite species (58%), carried at least one of the three bacteria. We found
Wolbachia in the herbivorous spider mites Tetranychus urticae and Bryobia rubrioculus, with the former also carrying Spiroplasma and the latter also carrying Cardinium. Cardinium was furthermore found in two populations of the predatory mite Euseius finlandicus and the spider mite Eotetranychus uncatus. Spiroplasma was detected in the predatory mite Neoseiulus californicus. All bacteria positive PCR products were sequenced, submitted to GenBank and analyzed in BLAST queries. We found high similarities
to complete identity with bacteria found in the same and different mite species but also with bacteria found in insect species
like ladybirds, butterflies and minute pirate bugs, Orius. We discuss the significance of potential (multiple) infections with the investigated bacteria for biological control. 相似文献
16.
We generated and analyzed microsatellite genotypic data and mtDNA sequence data from the fire ant Solenopsis invicta collected from two separate infested areas (Taoyuan and Chiayi) in Taiwan to infer the population and colony structure of
these recently established populations. These genetic analyses revealed the following patterns: 1) Relatedness among worker
nestmates was significantly greater than zero for both social forms from both populations; 2) No significant isolation by
distance was found among nests within each social form from either population; 3) Significant mtDNA but no nuclear differentiation
occurs between sympatric social forms in Taoyuan; 4) Molecular signatures of genetic bottlenecks associated with recent introductions
are evident in both populations; and 5) The two sampled populations, Taoyuan and Chiayi, are highly genetically differentiated
at both the nuclear or mtDNA genomes and most likely derive from two separate introductions into Taiwan. While results from
these analyses generally were consistent with predictions based on the known biology of these ants and similar studies of
S. invicta in the U.S.A. and South America, some patterns likely reflect the recent introduction and human-mediated inadvertent transport
of ants in Taiwan. This is the first study to investigate the population and colony structure of fire ants in Taiwan and results
from our study represent an important contribution to the ongoing efforts aimed at eradicating this invasive pest in Taiwan.
Received 18 June 2007; revised 11 October 2007; accepted 17 October 2007. 相似文献
17.
Mariano A. Rodriguez-Cabal Katharine L. Stuble Benoit Guénard Robert R. Dunn Nathan J. Sanders 《Biological invasions》2012,14(3):557-565
By disrupting the structure of native ant assemblages, invasive ants can have effects across trophic levels. Most studies
to date, however, have focused on the impacts just two species (Linepithema humile and Solenopsis invicta). The impacts of many other invasive ant species on ecological processes in their introduced range are unknown. In this study
we tested the hypothesis that the invasive ant Pachycondyla chinensis disrupts ant-seed dispersal mutualisms by displacing native ant species, especially the keystone mutualist Aphaenogaster rudis, while failing to disperse seeds itself. In a paired design we measured the impact of P. chinensis on the native ant-plant seed dispersal mutualism. The number of A. rudis workers was 96% lower in invaded than in intact plots, and the number of seeds removed was 70% lower in these plots. Finally,
in invaded plots the abundance of Hexastylis arifolia, a locally abundant myrmecochorous plant, was 50% lower than in plots where P. chinensis was absent. A parsimonious interpretation of our results is that P. chinensis causes precipitous declines in the abundance of A. rudis within invaded communities, thereby disrupting the ant-plant seed dispersal mutualisms and reducing abundances of ant-dispersed
plants. In sum, the magnitude of the effects of P. chinensis on seed dispersal is quantitatively similar to that documented for the intensively studied invasive Argentine ant. We suggest
that more studies on the impacts of less-studied invasive ant species on seed dispersal mutualisms may increase our knowledge
of the effects of these invaders on ecosystem function. 相似文献
18.
19.
Colony social organization in the fire ant Solenopsis invicta appears to be under strong genetic control. In the invasive USA range, polygyny (multiple queens per colony) is marked by
the presence of the Gp-9
b
allele in most of a colony’s workers, whereas monogyny (single queen per colony) is associated with the exclusive occurrence
of the Gp-9
B
allele. Ross and Keller, Behav Ecol Sociobiol 51:287–295 (2002) experimentally manipulated social organization by cross-fostering queens into colonies of the alternate form, thereby changing
adult worker Gp-9 genotype frequencies over time. Although these authors showed that social behavior switched predictably when the frequency
of b-bearing adult workers crossed a threshold of 5–10%, the possibility that queen effects caused the conversions could not be
excluded entirely. We addressed this problem by fostering polygyne brood into queenright monogyne colonies. All such treatment
colonies switched social organization to become polygyne, coincident with their proportions of b-bearing workers exceeding 12%. Our results support the conclusion that polygyny in S. invicta is induced by a minimum frequency of colony workers carrying the b allele, and further confirm that its expression is independent of queen genotype or history, worker genotypes at genes not
linked to Gp-9, and colony genetic diversity. 相似文献
20.
Tabata J Hattori Y Sakamoto H Yukuhiro F Fujii T Kugimiya S Mochizuki A Ishikawa Y Kageyama D 《Microbial ecology》2011,61(2):254-263
Bacteria of the genus Spiroplasma are widely found in plants and arthropods. Some of the maternally transmitted Spiroplasma endosymbionts in arthropods are known to kill young male hosts (male killing). Here, we describe a new case of Spiroplasma-induced male killing in a moth, Ostrinia zaguliaevi. The all-female trait caused by Spiroplasma was maternally inherited for more than 11 generations but was spontaneously lost in several lineages. Antibiotic treatment
eliminated the Spiroplasma infection and restored the 1:1 sex ratio. The survival rates and presence/absence of the W chromosome in the embryonic and
larval stages of O. zaguliaevi showed that males were selectively killed, exclusively during late embryogenesis in all-female broods. Based on phylogenetic
analyses of 16S rRNA, dnaA and rpoB gene sequences, the causative bacteria were identified as Spiroplasma belonging to the tick symbiont Spiroplasma ixodetis clade. Electron microscopy confirmed bacterial structures in the follicle cells and follicular sheath of adult females. Although
many congeneric Ostrinia moths harbor another sex ratio-distorting bacterium (Wolbachia), only O. zaguliaevi harbors Spiroplasma. 相似文献