Effect of Mature Colony Density on Colonization and Initial Colony Survivorship in Atta capiguara, a Leaf-Cutting Ant

Fowler, H. G.; Robinson, S.; Diehl, Janina M. C.

doi:10.2307/2387894

Cited by 15 publications

(7 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, unsuccessful establishment of fungus gardens by foundress queens who have dug chambers may be a frequent event (Autuori 1941). Once the garden is established, incipient colonies are still vulnerable to being raided by army ants and larger leaf-cutting ant colonies (Autuori 1950;Cherrett 1968;Rockwood 1973;Fowler 1982;Fowler et al 1984). Leaf-cutting ant colonies need to grow quickly in order to fend off attacks by predators, including other conspecific ant colonies, in order to reach reproductive maturity and potentially to compete successfully for leaf material with other Atta colonies in the population (Weber 1972).…”

Section: Introductionmentioning

confidence: 99%

Prevalence and impact of a virulent parasite on a tripartite mutualism

2001

View full text Add to dashboard Cite

The prevalence and impact of a specialized microfungal parasite (Escovopsis) that infects the fungus gardens of leaf-cutting ants was examined in the laboratory and in the field in Panama. Escovopsis is a common parasite of leaf-cutting ant colonies and is apparently more frequent in Acromyrmex spp. gardens than in gardens of the more phylogenetically derived genus Atta spp. In addition, larger colonies of Atta spp. appear to be less frequently infected with the parasite. In this study, the parasite Escovopsis had a major impact on the success of this mutualism among ants, fungi, and bacteria. Infected colonies had a significantly lower rate of fungus garden accumulation and produced substantially fewer workers. In addition, the extent of the reduction in colony growth rate depended on the isolate, with one isolate having a significantly larger impact than two others, suggesting that Escovopsis has different levels of virulence. Escovopsis is also spatially concentrated within parts of ant fungus gardens, with the younger regions having significantly lower rates of infection as compared to the older regions. The discovery that gardens of fungusgrowing ants are host to a virulent pathogen that is not related to any of the three mutualists suggests that unrelated organisms may be important but primarily overlooked components of other mutualistic associations.

show abstract

Section: Introductionmentioning

confidence: 99%

Prevalence and impact of a virulent parasite on a tripartite mutualism

2001

View full text Add to dashboard Cite

show abstract

“…The palatable forage hypothesis explains leafcutter ant demography in relation to adjacent vegetation, to which the ants only access a few months after nest establishment (Autuori, 1941;Fowler, 1987;Fowler et al, 1983;Cortés-Pérez and León-Sicard, 2003). The suitable-soil hypothesis emphasizes the importance of soil physiochemical conditions in determining nest densities as a result of their effect on nest founding.…”

Section: Resultsmentioning

confidence: 99%

The relationship between soil variables and leafcutter ant (Atta sexdens) nest distribution in the Colombian Amazon

Gils

Gaigl

Gómez³

2010

Insect. Soc.

View full text Add to dashboard Cite

We determined the relationships between several soil variables and the distribution of leafcutter ant (Atta sexdens) nests on the Colombian shore of the Amazon River. Seven habitats were identified in which nests were consistently present or absent. Soil samples for physiochemical analysis were taken near nest sites in three habitats where nests were present and from randomly selected sites in four other habitats where nests were absent. Percent canopy cover and soil resistance were also measured for each site. Almost all of the 20 identified soil variables were significantly different between habitats with and without A. sexdens nests, and the values of all variables were heterogeneous between the seven habitats. The most important variables correlated with leafcutter ant nest presence were percent canopy cover (positively), percent silt, soil resistance at 0-20 cm, and pH (all negatively). We deduced a binomial and a multinomial logistic regression which showed how each of these variables was related to nest presence and habitat, respectively. We describe how each variable may affect leafcutter ant nest development, especially in its earliest stages, and therefore influences nest distribution. We propose a suitable-soil hypothesis which, complementary to the palatable forage hypothesis, aims to explain patterns in leafcutter ant nest demography based on soil conditions.

show abstract

“…For Atta capiguara , fewer than 2% of incipient nests survive through the claustral stage (i.e., when the first workers emerge) [29], but successful nest establishment also depends on the local density of mature colonies. A review of the limited data for Atta gives comparable figures for other species [28], although factors other than disease may also be important.…”

Section: Discussionmentioning

confidence: 99%

Leaf endophyte load influences fungal garden development in leaf-cutting ants

et al. 2012

View full text Add to dashboard Cite

BackgroundPrevious work has shown that leaf-cutting ants prefer to cut leaf material with relatively low fungal endophyte content. This preference suggests that fungal endophytes exact a cost on the ants or on the development of their colonies. We hypothesized that endophytes may play a role in their host plants’ defense against leaf-cutting ants. To measure the long-term cost to the ant colony of fungal endophytes in their forage material, we conducted a 20-week laboratory experiment to measure fungal garden development for colonies that foraged on leaves with low or high endophyte content.ResultsColony mass and the fungal garden dry mass did not differ significantly between the low and high endophyte feeding treatments. There was, however, a marginally significant trend toward greater mass of fungal garden per ant worker in the low relative to the high endophyte treatment. This trend was driven by differences in the fungal garden mass per worker from the earliest samples, when leaf-cutting ants had been foraging on low or high endophyte leaf material for only 2 weeks. At two weeks of foraging, the mean fungal garden mass per worker was 77% greater for colonies foraging on leaves with low relative to high endophyte loads.ConclusionsOur data suggest that the cost of endophyte presence in ant forage material may be greatest to fungal colony development in its earliest stages, when there are few workers available to forage and to clean leaf material. This coincides with a period of high mortality for incipient colonies in the field. We discuss how the endophyte-leaf-cutter ant interaction may parallel constitutive defenses in plants, whereby endophytes reduce the rate of colony development when its risk of mortality is greatest.

show abstract

Effect of Mature Colony Density on Colonization and Initial Colony Survivorship in Atta capiguara, a Leaf-Cutting Ant

Cited by 15 publications

References 8 publications

Prevalence and impact of a virulent parasite on a tripartite mutualism

Prevalence and impact of a virulent parasite on a tripartite mutualism

The relationship between soil variables and leafcutter ant (Atta sexdens) nest distribution in the Colombian Amazon

Leaf endophyte load influences fungal garden development in leaf-cutting ants

Contact Info

Product

Resources

About