Gregory Chism Abstracts

Gregory Chism
Ph.D. Candidate
Entomology & Insect Sciences

Advances in Complex Systems - From Ecology to Economics - Lake Como School of Advanced Studies

Como, Italy
July 26-29, 2019

Social insects represent an example of how complex systems propagate in the natural world. In social insects, individuals in the colony make decisions on what task to perform through interactions with each member and the environment. A fascinating trait of social insects is the centralized living that they choose in the form of nests. The nest architectures of ants are an example of an extended phenotype, present across many social insect taxa. ‘Extended phenotypes’ are organism traits that extend into the environment: for example, in social insects, the nest, built by the colony, then can serve as a way for ants to regulate the environment present within their nests. Much attention has been given how the organism’s behavior shapes traits like nest architecture (e.g. wall shapes, nest depth, etc.), while the potential feedback from this nest architecture onto the colony’s behavior has been largely unexplored. This is important since the shape of the nest can influence how well tasks are performed in the nest and components of the colony’s complex system propagate. The ant Temnothorax rugatulus provides an ideal model system to investigate the effects of nest architecture on how colonies organize themselves in their nest environment, thus providing insight into the interactions between these architectures and behavioral expressions. We tested the hypotheses that (i) nest architecture affects ant worker, brood (immature ants), and queen (reproductive ants) distributions within the nest, in particular (ii) that nest architecture would determine extent and distribution micro-territories of workers in the nest, and that (iii) random ant movement patterns explain the worker and brood distributions in the nest. Besides investigating the feedback between nest architecture and colony organization, our results provide insights into how worker tasks are decided, since the distributions of workers and brood in the nest affects how often different workers are likely to encounter tasks that need to be completed. Our results illuminate the direct influences of the nest architecture on how labor is divided in social insect colonies.

Abstract for Lay Audience

Social insects represent an example of how many parts interact together into a whole system in the natural world. In social insects, this means that a colony is not ruled by one leader (or queen) that commands what task to perform, but instead colonies accomplish tasks through individual choices. A fascinating trait of social insects is the nest, which acts as a central hub that each colony lives in. The nest architectures of ants are an example of an extended phenotype, present across many social insect taxa. ‘Extended phenotypes’ are organism traits that extend into the environment: for example, in social insects, the nest, built by the colony, then can serve as a way for ants to regulate the environment present in their nests. Much attention has been given how the organism’s behavior shapes traits like nest architecture (e.g. wall shapes, nest depth, etc.), while the potential feedback from this nest architecture onto the colony’s behavior has been largely unexplored. This is important since the shape of the nest can influence how well tasks are performed in the nest. The ant Temnothorax rugatulus provides an ideal model system to investigate the effects of nest architecture on how colonies organize themselves in their nest environments, thus providing insight into the interactions between these architectures and behavioral expressions. We tested the hypotheses that (i) nest architecture affects ant worker, brood (immature ants), and queen (reproductive ants) distributions within the nest, in particular (ii) that nest architecture would determine extent and distribution micro-territories of workers in the nest, and that (iii) movement without a goal explains the worker and brood distributions in the nest. Besides investigating the feedback between nest architecture and colony organization, our results provide insights into how worker tasks are decided, since the distributions of workers and brood in the nest affects how often different workers are likely to encounter tasks that need to be completed. Our results illuminate the direct influences of the nest architecture on how labor is divided in social insect colonies.