Allogrooming, Self-Grooming, and Touching Behavior: Contamination Routes of Leaf-Cutting Ant Workers Using a Fat-Soluble Tracer Dye

Abstract

The aim of this study was to determine whether worker self-grooming, allogrooming, and direct contact promotes the dispersal of substances among members of the colony. For this purpose, a tracer (Sudan III dye) was applied topically to a worker ant and the social interactions between the worker with the tracer and workers without the tracer were studied. Additionally, the worker heads were dissected to visualize whether or not the post-pharyngeal gland was stained. The post-pharyngeal glands from 50% to 70% of workers were stained depending on the size of the group. With the increase in the experimental group size, the frequency of interactions between workers increased, with touching being the most frequent behavior. The tracer dye was probably passed on by direct contact between workers, followed by self-grooming and allogrooming. These behaviors are responsible for the rapid dispersal of substances among colony members as observed in our experiment. The results therefore support the hypothesis that contact with substances promotes the contamination of nestmates, even in the absence of feeding, serving as a model for further studies on the contamination of workers with the active ingredients of insecticides.

Effects of Entomopathogenic Fungi on Individuals as Well as Groups of Workers and Immatures of Atta sexdens rubropilosa Leaf-Cutting Ants

“…This is probably caused because the ants are contaminated with a large amount of fungal conidia and cannot efficiently control the spread of spores. In this context, allogrooming does not work anymore with increased infected individuals, this it was observed by Camargo et al [ 51 ].…”

“…Because when baits with fungal spores are used, few workers have direct contact with the spores [ 55 ]. The other workers are contaminated through interactions between individuals, as proved by Camargo et al [ 51 ], who used a tracer dye whose dissemination was attributed to contact between workers. However, when it comes to entomopathogenic fungi, this dissemination does not occur because ants recognize entomopathogenic agents and use individual and group defense mechanisms that inhibit fungal action [ 15 ].…”

Formicidal activity of indole derivatives on Atta opaciceps (Borgmeier): Lethal, behavioural and locomotive effects

“…The reduction in displacement and walking speed and increased immobility in the collective bioassays when compared to the individual ones indicate the influence of the social interactions. The frequency of these events is increasing with an increasing number of individuals (Camargo et al., ). In these situations, the ants tend to be immobile and, therefore, the walking speed and the displacement decrease.…”

“…The frequency of these events is increasing with an increasing number of individuals (Camargo et al, 2017). In these situations, the ants tend to be immobile and, therefore, the walking speed and the displacement decrease.…”

“…In the group behaviour experiment, the results indicate that untreated individuals did not recognize contaminated individuals as a threat for the group, since behaviours (antennation, avoidance, allogrooming and trophallaxis) were not altered (Table ). Antennation, allogrooming and trophallaxis behaviours contribute to rapid dispersion of compounds among nestmates, promoting further contamination of workers (Camargo, Puccini, Forti, & Matos, ). Thus, the dispersion of compounds among nestmates through these behaviours should not be affected.…”