Use of Seeds as Fungus Garden Substrate Changes the Organization of Labor Among Leaf-Cutting Ant Workers.

Seeds of different plant species constitute an alternative but also significant substrate that leaf-cutting ants use to cultivate their fungus garden. However, how they are processed inside the nest and if their use implies differential allocation of worker size classes are still poorly known. Using laboratory colonies of Acromyrmex subterraneus (Forel) as a model, the behaviors related to the processing of three different seeds (sesame, guava, and grape) as fungus substrate were listed. At the same time, we measured how each worker size class contributed to the execution of these behaviors by registering their respective frequency. It was found that medium-sized (1.2 > head width < 1.6 mm) and minimum-sized (head width <1.1 mm) workers assumed the role of incorporation for sesame and grape seeds, respectively. Major-sized workers (head width >1.7 mm) were concentrated on licking and holding guava seeds. Tegument removal was the only task observed that differs between treatment of seeds and treatment of leaves before their incorporation, as described in the literature. It was verified that different species of seeds imply a differential allocation of worker size classes and the inclusion or exclusion of some tasks from the behavioral repertoire. Regardless of the substrate type, leaf-cutting ant workers follow a coordinated and specialized procedure to cultivate the fungus garden but always maintain a high degree of cooperation.

Potencial mirmecológico na vetoração mecânica de helmintos em gatos / Myrmecological potential in mechanic vectoring of helminthes in cats rescue center

Vector potential of ants in mechanic dissemination of helminthes in a cat rescue center was analyzed in this study. Ants walking over cat's food and feces were collected and conditioned in distilled water. Cat feces were collected too. Ants were identified and the water where they were conditioned was observed on optic microscope. It was made the simple sedimentation technique to analyze feces. The results show that ants species Pheidole and Paratrechina can be potential vectors of nematode eggs, mainly Ascaridida, Toxocaridae.

The influence of the scout upon the decision-making process of recruited workers in three Acromyrmex species (Formicidae: Attini).

We examined how the information communicated by a scout worker influences the plant species transported by recruited workers in Acromyrmex balzani, Acromyrmex rugosus, and Acromyrmex crassispinus, three species of leaf-cutting ant that have different substrate and habitat preferences. We verified that certain plant species were more likely to be transported than others and that recruitment occurs. We found that recruited workers were more likely to transport non-preferred plant species when they were recruited to these by scout workers. The results suggest that the scout worker can communicate information about plant identity to recruited workers, but that recruited workers integrate the information communicated with their own experience during the decision-making process.