The internal structure of three nests Atta laevigata was studied in Botucatu city, São Paulo State, Brazil. Two were excavated through the opening trenches and one cement-moulded to enable a better view structures. presented similar structure, with depths number chambers varying as function loose soil area nests. ranged from 1149 7864, reaching deep 7 m underground. Chamber volume 0.03 51 l. foraging tunnels extended far 70 region. this species are deepest within genus have highest chambers.

Abstract This study describes and quantifies the behavioural acts of two laboratory colonies Acromyrmex subterraneus brunneus by investigating worker age polyethism. Twenty‐nine were recorded during 19‐week observation period. Young individuals performed tasks inside nest related to brood care for fungus garden, whereas older activities outside such as foraging in waste chamber. The average longevity (±SD) was 108.21 ± 3.30, 109.15 1.92 122.71 1.55 days large, medium small workers,...

Abstract: This work was carried out to determine the internal and external structures of Atta bisphaerica (Forel) nests. Six nests were excavated during excavation, all data referring chambers tunnels recorded. Three had been internally cement‐moulded, which enabled a better view chamber tunnel structures. presented similar structural pattern, varying only in number as function mound area. Chambers spherical with two communication tunnels. Internal an elliptical section, sometimes circular,...

Thirty-nine yeast strains were recovered from a field nest of primitive and putative novel attine ant species in the genus Myrmicocrypta (Hymenoptera: Formicidae: tribe Attini). Yeasts isolated fungus garden waste deposit included Candida dubliniensis , oleophila Cryptococcus haglerorum Hanseniaspora uvarum . In addition, one morphological type was overwhelmingly. Sequencing data partial large-subunit (LSU) rDNA internal transcribed spacer (ITS) region coupled with physiological...

Leaf-cutting ants modify the properties of soil adjacent to their nests. Here, we examined whether such an ant-altered environment impacts belowground fungal communities. Fungal diversity and community structure from fungus garden chambers Atta sexdens rubropilosa bisphaerica, two widespread leaf-cutting in Brazil, were determined compared with non-nest soils. Culture-dependent methods revealed similar species richness but different compositions between both types Penicillium janthinellum...

Leaf-cutting ants are controlled with toxic baits. For the method's greater efficiency, baits must be distributed and processed by workers during fungus cultivation. To test hypotheses whether mode of action active ingredients, which blocks sodium channels interrupts production ATP in mitochondria, interferes fragment distribution nests; dispersion pellets fragments cultivation was assessed, spatially referencing onto garden. Pellets were randomly distributed, but amount influenced way that...

Abstract BACKGROUND Leaf‐cutting ants (LCAs) of the genera Atta and Acromyrmex (Hymenoptera: Formicidae) are important pests forest plantations, agriculture livestock. Toxic baits containing active ingredients fipronil or sulfluramid main method used to control LCAs. Insecticide dispersion among members an LCA colony during with toxic bait is not well understood. The objective study was determine whether self‐grooming, allogrooming touching behavior sexdens workers disperses insecticides...

The aim of this study was to determine whether worker self-grooming, allogrooming, and direct contact promotes the dispersal substances among members colony. For purpose, a tracer (Sudan III dye) applied topically ant social interactions between with workers without were studied. Additionally, heads dissected visualize or not post-pharyngeal gland stained. glands from 50% 70% stained depending on size group. With increase in experimental group size, frequency increased, touching being most...

Abstract Queens of the leaf‐cutting ant species Atta laevigata and capiguara were collected soon after their mating flight maintained in laboratory until death. Ant corpses showing signs contamination by insect pathogenic fungi selected for fungal identification. Filamentous such as Beauveria bassiana Paecilomyces lilacinus actively sporulated ant’s corpses. This is first report latter fungus on reproductives ants. The fact that queens may acquire filamentous including saprophytic potential...

The relationship between the queens' lipid content and nest growth (population size, biomass architecture) was studied from founding up to 1 year. Nests aged 3, 4, 5, 6, 9 12 months were dug in field, their dimensions measured. ant population fungus garden also collected. sample taken laboratory where we counted worker weighed (fungus plus offspring) queens. Queens separated for determination of lipids. bodies queens decreased first months, then stabilized (at 4–6 months) before increasing...

We present a detailed description of the predatory behavior beetle Canthon virens Mannerheim, 1829, on leafcutter ant Atta sp. observed 51 acts predation, which were also recorded film and subjected to behavioral analysis. exhibited 28 behaviors while predating upon queens. Adult beetles search for queens flying in zigzag pattern, 15 20 cm above ground. After catching queen, predator stands its back starts cutting queen cervix. Once prey is decapitated, rolls it until an insurmountable...

Foraging networks are a key element for ant colonies because they facilitate the flow of resources from environment to nest and allow sharing information among individuals. Here we report results an 8-month survey, extending November 2009 June 2010, foraging four mature Atta bisphaerica, species grass-cutting which is considered as pest in Brazil. We found that distribution effort was strongly influenced by landscape features around nests, particular permanently wet parts pasture nests were...