Individual and collective foraging decisions: a field study of worker recruitment in the gypsy ant Aphaenogaster senilis

In social insects, the decision to exploit a food source is made both at the individual (e.g., a worker collecting a food item) and colony level (e.g., several workers communicating the existence of a food patch). In group recruitment, the recruiter lays a temporary chemical trail while returning from the food source to the nest and returns to the food guiding a small group of nestmates. We studied how food characteristics influence the decision-making process of workers changing from individual retrieving to group recruitment in the gypsy ant Aphaenogaster senilis. We offered field colonies three types of prey: crickets (cooperatively transportable), shrimps (non-transportable), and different quantities of sesame seeds (individually transportable). Colonies used group recruitment to collect crickets and shrimps, as well as seeds when they were available in large piles, while small seed piles rarely led to recruitment. Foragers were able to “measure” food characteristics (quality, quantity, transportability), deciding whether or not to recruit, accordingly. Social integration of individual information about food emerged as a colony decision to initiate or to continue recruitment when the food patch was rich. In addition, group recruitment allowed a fast colony response over a wide thermal range (up to 45°C ground temperature). Therefore, by combining both advantages of social foraging (group recruitment) and thermal tolerance, A. senilis accurately exploited different types of food sources which procured an advantage against mass-recruiting and behaviorally dominant species such as Tapinoma nigerrimum and Lasius niger.Peer reviewe

Individual and collective problem-solving in a foraging context in the leaf-cutting ant Atta colombica

SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Skills training groups for men with ADHD in compulsory care due to substance use disorder: a feasibility study

Dialectical behavior therapy (DBT)-based skills training has been developed and previously evaluated for adults with ADHD in a psychiatric outpatient context. The aim of the present study was to evaluate the feasibility of DBT-based skills training as a voluntary intervention for men with ADHD in compulsory care due to severe substance abuse. Forty sufficiently detoxified men with ADHD in compulsory care due to life-threatening substance use disorder (SUD) were included in DBT-based skills training groups. Self- and staff-rating scales were administered before and after the treatment. The refusal rate was 42.9 %. Of those who started the DBT-based skills training, 70 % completed the treatment (attendance at =75 % of the sessions). The treatment acceptability was good. Both ADHD and psychiatric symptoms decreased from pre- to post-intervention in self-ratings, but not in staff ratings. The patients reported improved general well-being. The correlation between self- and staff ratings was poor. Motivation for voluntary nonpharmacological treatment was low in a compulsory care context. However, the results indicate that a DBT-based skills training program for adults with ADHD may be feasible for some patients with ADHD in combination with SUD in compulsory care, provided that considerable resources are allocated with adjustments to the target group and compulsory care context