Consequences of envenomation: red imported fire ants have delayed effects on survival but not growth of native fence lizards

2010 ◽  
Vol 37 (7) ◽  
pp. 566 ◽  
Author(s):  
Tracy Langkilde ◽  
Nicole A. Freidenfelds
Keyword(s):  
Growth Rates ◽  
Native Species ◽  
Selective Pressure ◽  
The Body ◽  
Fire Ants ◽  
Fire Ant ◽  
Control Treatment ◽  
Aggressive Interactions ◽  
Ant Venom ◽  
Body Sizes

Context Aggressive encounters, including those with venomous species, impose selective pressure on native species. Immediate lethal outcomes of these encounters have been the primary focus of research in this field. However, not all aggressive interactions result in immediate mortality, and indirect consequences of aggressive interactions may be an equally important but under-considered selective force. The red imported fire ant is a globally important venomous invader that imposes novel selective pressure on native communities. Aims We examined indirect effects of fire ant envenomation on native fence lizard growth rates and subsequent survival. Methods Fence lizards are subject to fire ant envenomation in the field when they eat fire ants (they are stung inside the mouth) and through fire ant attack (they are stung on the body). We quantified body sizes of adult lizards from fire ant-invaded and uninvaded sites. We then experimentally exposed hatchling fence lizards to the two modes of fire ant envenomation, and quantified their growth and survival over 1 year. Key results Lizards from fire ant-invaded sites were smaller than those from an uninvaded site, even at similar latitudes. However, in contrast to studies on other native taxa, we found no effect of fire ant venom on growth rates of lizards from naïve or fire ant-invaded populations. Lizards exposed to fire ant venom, through both eating and attack, experienced higher rates of delayed mortality, with 34% of lizards dying 1–11 weeks post-envenomation compared with 12% of lizards in the control treatment. These patterns were true for fire ant naïve populations as well as those exposed to fire ants for ~35 generations. Conclusions These results suggest that the smaller body sizes observed in fence lizards from fire ant-invaded sites are not a consequence of exposure to fire ant venom. However, fence lizards from both sites suffer delayed survival costs of fire ant envenomation. Implications The present study highlights the importance of considering indirect fitness consequences of aggressive encounters if we are to fully understand the ecological and evolutionary consequences of these interactions, and adequately manage and predict the impacts of invasive species.

scholarly journals Evading invaders: the effectiveness of a behavioral response acquired through lifetime exposure

2012 ◽  
Vol 23 (3) ◽  
pp. 659-664 ◽  
Author(s):  
N. A. Freidenfelds ◽  
T. R. Robbins ◽  
T. Langkilde
Keyword(s):  
Native Species ◽  
Antipredator Behavior ◽  
Fire Ants ◽  
Fire Ant ◽  
Sceloporus Undulatus ◽  
Heritable Trait ◽  
Lifetime Exposure ◽  
Juvenile Behavior ◽  
Global Threat ◽  
The Impact

Abstract Understanding the mechanisms driving adaptations to survive agonistic interactions, and their function, provides insight into how native species adapt to aggressive invaders, a growing global threat. We staged encounters between native fence lizards (Sceloporus undulatus) and red imported fire ants (Solenopsis invicta) on and off the ant mound (nest) to examine the effectiveness of lizard antipredator behavior through ontogeny while focusing on the impact of lifetime and evolutionary exposure to this invasive threat. We used field-caught and lab-reared lizards from a fire ant–invaded and an uninvaded site. In ∼90% of cases, fire ants found lizards within 12 min in natural lizard habitat. Lizards that performed rapid twitches of their body and/or fled after initial encounter with a fire ant scout reduced their risk of having additional fire ants recruit to the attack. The majority of lizards that had been exposed to fire ants within their lifetime (field-caught lizards from the invaded site) behaviorally responded to attack, whereas relatively few lizards that were naïve to fire ants (all lab-reared lizards and field-caught lizards from the uninvaded site) responded. Because fewer adult lizards responded to fire ants than juveniles, they were recruited to by additional attacking ants significantly more than were juveniles. Our data suggest that the higher percentage of responsive adults within invaded populations is the result of within-lifetime selection acting against unresponsive adults, and/or lifetime exposure to fire ants triggering the retention of this juvenile behavior into adulthood, rather than selection acting on a heritable trait across generations.

Postmetamorphic growth rates in a natural population of Fowler's toad, Bufo woodhousei fowleri

1974 ◽  
Vol 52 (12) ◽  
pp. 1489-1498 ◽  
Author(s):  
Raymond D. Clarke
Keyword(s):  
Growth Rates ◽  
The Body ◽  
Individual Growth ◽  
Length Increase ◽  
Sexual Characteristics ◽  
Size Growth ◽  
Body Sizes ◽  
Bufo Woodhousei ◽  
Fowler's Toad ◽  
Toad Bufo

A population of Fowler's toad (Bufo woodhousei fowleri) living on a golf course in New Haven, Connecticut, was studied for 3 years by the capture–mark–recapture method. Individual growth rates were determined using tibia length, which is isometric with body length, as the measure of size. Growth was rapid, with an average 6.58-fold length increase during the 1st year after metamorphosis. Males began to show secondary sexual characteristics about 1 year after metamorphosis; at this age the cohort began to overlap in body size with the older males. Females grew faster than males, but also reached a larger size, and the body sizes of the maturing female cohort began to overlap with the older females 1 month later than the males. The growth curve for length was inflected, which is predicted by von Bertalanffy's growth model.

Intra- and inter-specific variation in alarm pheromone produced by Solenopsis fire ants

2017 ◽  
Vol 108 (5) ◽  
pp. 667-673 ◽  
Author(s):  
L. Hu ◽  
R.R. Balusu ◽  
W.-Q. Zhang ◽  
O.S. Ajayi ◽  
Y.-Y. Lu ◽  
...  
Keyword(s):  
United States ◽  
Native Species ◽  
Alarm Pheromone ◽  
Relative Weight ◽  
Invasion Success ◽  
Fire Ants ◽  
Pheromone Component ◽  
Fire Ant ◽  
Southern United States ◽  
Specific Variation

AbstractSome fire ants of the genus Solenopsis have become invasive species in the southern United States displacing native species by competition. Although the displacement pattern seems clear, the mechanisms underlying competitive advantage remain unclear. The ability of ant workers to produce relatively larger amount of alarm pheromone may correspond to relative greater fitness among sympatric fire ant species. Here we report on quantitative intra-specific (i.e. inter-caste) and inter-specific differences of alarm pheromone component, 2-ethyl-3,6-dimethylpyrazine (2E36DMP), for several fire ant species. The alarm pheromone component was extracted by soaking ants in hexane for 48 h and subsequently quantified by gas chromatography-mass spectrometry at single ion monitoring mode. Solenopsis invicta workers had more 2E36DMP than male or female alates by relative weight; individual workers, however, contained significantly less pyrazine. We thus believe that alarm pheromones may serve additional roles in alates. Workers of Solenopsis richteri, S. invicta, and hybrid (S. richteri × S. invicta) had significantly more 2E36DMP than a native fire ant species, Solenopsis geminata. The hybrid fire ant had significantly less 2E36DMP than the two parent species, S. richteri and S. invicta. It seems likely that higher alarm pheromone content may have favored invasion success of exotic fire ants over native species. We discuss the potential role of inter-specific variation in pyrazine content for the relationship between the observed shifts in the spatial distributions of the three exotic fire ant species in southern United States and the displacement of native fire ant species.

scholarly journals The allergic response mediated by fire ant venom proteins

2018 ◽  
Author(s):  
Zamith-Miranda Daniel ◽  
Eduardo G. P. Fox ◽  
Ana Paula Monteiro ◽  
Diogo Gama ◽  
Luiz E. Poublan ◽  
...  
Keyword(s):  
Allergic Response ◽  
Fire Ants ◽  
Fire Ant ◽  
Practical Reasons ◽  
Physiological Effects ◽  
Protein Extract ◽  
Venom Protein ◽  
Ant Venom ◽  
Venom Proteins ◽  
Biomedical Interest

AbstractFire ants are widely studied, invasive and venomous arthropod pests. There is significant biomedical interest in immunotherapy against fire ant stings. However, mainly due to practical reasons, the physiological effects of envenomation has remained poorly characterized. The present study takes advantage of a recently-described venom protein extract to delineate the immunological pathways underlying the allergic reaction to fire ant venom toxins. Mice were injected with controlled doses of venom protein extract. Following sensitization and a second exposure, a marked footpad swelling was observed. Based on eosinophil recruitment and production of Th2 cytokines, we hereby establish that fire ant proteins per se can lead to an allergic response, which casts a new light into the mechanism of action of these toxins.

scholarly journals The Economics of Optimal Foraging by the Red Imported Fire Ant

2020 ◽  
Vol 49 (2) ◽  
pp. 304-311 ◽  
Author(s):  
Karl A Roeder ◽  
Rebecca M Prather ◽  
Anna W Paraskevopoulos ◽  
Diane V Roeder
Keyword(s):  
Native Species ◽  
Inflection Point ◽  
Fire Ants ◽  
Fire Ant ◽  
Red Imported Fire Ant ◽  
Ant Colonies ◽  
Collective Group ◽  
Solenopsis Invicta Buren ◽  
Discovery Time ◽  
Imported Fire Ant

Abstract For social organisms, foraging is often a complicated behavior where tasks are divided among numerous individuals. Here, we ask how one species, the red imported fire ant (Solenopsis invicta Buren) (Hymenoptera: Formicidae), collectively manages this behavior. We tested the Diminishing Returns Hypothesis, which posits that for social insects 1) foraging investment levels increase until diminishing gains result in a decelerating slope of return and 2) the level of investment is a function of the size of the collective group. We compared how different metrics of foraging (e.g., number of foragers, mass of foragers, and body size of foragers) are correlated and how these metrics change over time. We then tested the prediction that as fire ant colonies increase in size, both discovery time and the inflection point (i.e., the time point where colonial investment toward resources slows) should decrease while a colony’s maximum foraging mass should increase. In congruence with our predictions, we found that fire ants recruited en masse toward baits, allocating 486 workers and 148 mg of biomass, on average, after 60 min: amounts that were not different 30 min prior. There was incredible variation across colonies with discovery time, the inflection point, and the maximum biomass of foragers all being significantly correlated with colony size. We suggest that biomass is a solid indicator of how social taxa invest their workforce toward resources and hypothesize ways that invasive fire ants are able to leverage their enormous workforce to dominate novel ecosystems by comparing their foraging and colony mass with co-occurring native species.

scholarly journals Intraspecific and Intracolonial Variation in the Profile of Venom Alkaloids and Cuticular Hydrocarbons of the Fire AntSolenopsis saevissimaSmith (Hymenoptera: Formicidae)

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Eduardo Gonçalves Paterson Fox ◽  
Adriana Pianaro ◽  
Daniel Russ Solis ◽  
Jacques Hubert Charles Delabie ◽  
Bruno Cunha Vairo ◽  
...  
Keyword(s):  
Cryptic Species ◽  
Cuticular Hydrocarbons ◽  
Native Species ◽  
Geographical Location ◽  
Fire Ants ◽  
Fire Ant ◽  
The World ◽  
Chemical Profiles ◽  
Chemical Characters ◽  
Neotropical Ants

Fire ants are aggressive Neotropical ants that are extensively similar in general biology and morphology, making species identification difficult. Some fire ant species are top-rated pests spreading throughout the world by trade vessels. Many researchers attempted to sort between invasive and native species by using chemical characters, including patterns of venom alkaloids. The present study is the first to report intraspecific variation in some chemical characters, namely, cuticular hydrocarbons and venom alkaloids, within the Brazilian fire ant speciesSolenopsis saevissimaand also reports on within-nest variations among members of different castes. Two different haplotypes (cryptic species) ofS. saevissimawere clearly identified, one presenting a predominant combination of the venom alkaloidscis- andtrans-2-methyl-6-undecylpiperidine with the cuticular hydrocarbons C23, 3-Me-C23, 10-C25 : 1, C25, and 3-Me-C25, and the other a predominant combination ofcis- andtrans-2-methyl-6-tridecenylpiperidine with predominance of 12-C25 : 1, C25, 11-Me-C25, 3-Me-C25, 13-C27 : 1, C27, and 13-Me-C27. Intranest variations revealed that the proportions among these compounds varied sensibly among workers of different sizes, gynes, and males (no alkaloids were detected in the latter). Larva contained vestiges of the same compounds. The recorded chemical profiles are quite different from previous reports withS. saevissimasamples from São Paulo. The finds thus support other recent claims thatS. saevissimaincludes cryptic species; the study, moreover, adds the find that they can occur in the same geographical location.

Antileishmanial Activity of Fire Ant Venom Alkaloids

Planta Medica ◽  
2012 ◽  
Vol 78 (05) ◽  
Author(s):  
HMTB Hereath ◽  
BL Tekwani ◽  
NPD Nanayakkara
Keyword(s):  
Antileishmanial Activity ◽  
Fire Ant ◽  
Ant Venom

scholarly journals MICRONUTRIENT CONTENTS IN THE PROFILE OF A RECOVERED SOIL WITH SEWAGE SLUDGE AND NATIVE SPECIES OF ATLANTIC FOREST

FLORESTA ◽  
2019 ◽  
Vol 49 (3) ◽  
pp. 485
Author(s):  
Lívia Mara Lima Goulart ◽  
Marianne Fidalgo de Faria ◽  
Grasiela Spada ◽  
Thiago Tássio de Souza Silva ◽  
Iraê Amaral Guerrini
Keyword(s):  
Sewage Sludge ◽  
Atlantic Forest ◽  
Soil Profile ◽  
Native Species ◽  
Control Treatment ◽  
Mineral Fertilization ◽  
Promising Alternative ◽  
Final Destination ◽  
Potassium Supplementation

The use of sewage sludge in agriculture and recovery of degraded areas has been shown as a promising alternative for its final destination. Studies on micronutrient levels after sludge application are necessary to avoid soil contamination at toxic levels. The objective of this work was to verify the micronutrient contents in the soil profile and pH, up to one-meter-deep, nine years after the application of sewage sludge and planting of native species of the Atlantic Forest. The experiment was implemented in a degraded Quartzeneic Neosol and conducted in randomized blocks with four replicates and eight treatments, consisting of six doses of sewage sludge (0, 2.5, 5, 10, 15 and 20 Mg ha-1, with supplementation of potassium due to low concentration in the residue), besides the control treatment, mineral fertilization and only potassium supplementation. After nine years, the contents of all micronutrients evaluated presented a significant response to the application of the treatments, and the application of sewage sludge provided an increase in their contents. Soil pH remained stable at sites receiving mineral fertilization and potassium supplementation. Only manganese and zinc showed mobility in the soil profile. The application of sewage sludge in degraded soil increases the micronutrient content and decreases its movement in the soil profile, and the application of the maximum dose of the residue does not provide toxic levels of these elements in the soil in the long term.

scholarly journals Comparative Immature Morphology of Brazilian Fire Ants (Hymenoptera: Formicidae:Solenopsis)

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Eduardo Gonçalves Paterson Fox ◽  
Daniel Russ Solis ◽  
Mônica Lanzoni Rossi ◽  
Jacques Hubert Charles Delabie ◽  
Rodrigo Fernando de Souza ◽  
...  
Keyword(s):  
Intraspecific Variation ◽  
Solenopsis Invicta ◽  
Morphological Traits ◽  
Species Level ◽  
Fire Ants ◽  
Fire Ant ◽  
Solenopsis Geminata ◽  
Body Dimensions ◽  
Larval Instars ◽  
Genus Level

Although common in Brazil, the biology of the fire antSolenopsis saevissima(Smith) is still poorly studied. Larval descriptions are useful to genus-level ant systematics and sometimes to species-level taxonomy. This study presents a detailed description of juveniles ofS. saevissimafrom Brazil, which were compared with Brazilian specimens ofSolenopsis invictaBuren,Solenopsis geminata(Fabricius), andSolenopsis altipunctataPitts. Different larval instars were separated by diagnostic morphological traits which were confirmed by observing moults. Reproductive larvae could be easily sorted by their distinctive body dimensions and shape. Contrary to previous reports on this species, the larvae ofS. saevissimaproved to be generally identical to those ofS. invicta, while a few specimens resembled those of other close species, such asSolenopsis megergatesTrager. Mature larvae thus presented considerable intraspecific variation in some characters recently proposed to aid fire ant species separation (morphology of head hairs).

PRE-MATERNAL ISOLATION EFFECTS ON BEHAVIOUR AND ENDOCRINE FUNCTION OF OFFSPRING

1969 ◽  
Vol 62 (2) ◽  
pp. 367-384 ◽  
Author(s):  
A. M. Sackler ◽  
A. S. Weltman ◽  
R. Schwartz ◽  
P. Steinglass
Keyword(s):  
Locomotor Activity ◽  
Growth Rates ◽  
Female Offspring ◽  
The Body ◽  
Endocrine Function ◽  
Male And Female ◽  
Isolation Stress ◽  
Developmental Growth ◽  
Body Weights ◽  
And Control

ABSTRACT This report was designed to determine combined effects of maternal endocrine imbalances and abnormal behaviour due to prolonged isolation stress of female mice on the behaviour, developmental growth rate and endocrine function of their offspring. Sixty female albino mice averaging 19 g were divided equally into isolated and control groups. The isolated females were housed singly; control females were maintained in groups of 2 mice per cage. After observation of behavioural and physiological effects characteristic of isolation stress in the test mice, all isolated and control mice were mated after a 6½ month experimental, isolation period. No differences were observed in fertility and fecundity of the two groups of mothers. Analyses of developmental growth rates of the litters of the isolated versus control mothers showed significantly lower body weights in the test offspring at 3 and 4 weeks of age. The body weights of the female offspring remained significantly lower from the 4th to 11th weeks. The effects on the body weights of the male offspring declined and were no longer statistically significant at the 5th to 11 weeks. Locomotor activity at 4½ and 8 weeks of age was markedly or significantly higher in the male and female mice from isolated mothers. Tail-blood samples taken prior to autopsy at 5 and 11 weeks of age revealed significant decreases in the total leukocyte and eosinophil counts of both sexes. At the two ages, the absolute and relative spleen and thymus weights of the male and female offspring were markedly and/or significantly lower than the values observed in counterpart young from control females. Significant decreases were also observed in the absolute gonadal organ weights of both sexes at 11 weeks of age. The various data indicated inhibited growth rates, heightened locomotor activity and evasiveness, as well as evidence of increased adrenocortical function in the offspring from test mothers. The gonadal weight decreases suggested retarded gonadal development. Further studies using split-litter techniques are required to differentiate the effects of prenatal endocrine imbalances versus postnatal maternal influence (i. e., nursing care) on the offspring.

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