Gregory Chism Abstracts

Gregory Chism

Ph.D. Candidate

Entomology & Insect Sciences GIDP

International Union for the Study of Social Insects (IUSSI 2018)

Guaruja, Brazil

August 5-10, 2018

Nest architecture in ants is an example of an extended phenotype, present across many socialinsect 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 mechanism for microclimate regulation. Much attention has been given how the organism’s behavior shapes the extended phenotype, while the potential feedback from the phenotype (e.g. nest architecture) onto the colony’s behavior has been largely unexplored. The ant Temnothorax rugatulus provides an ideal model system to investigate the effects of nest architecture on colony organization, thus providing insight into the interactions between extended phenotypes and behavioral traits. We tested the hypotheses that (i) nest architecture affects worker and brood spatial distribution, in particular (ii) that nest architecture would determine extent and distribution of spatial fidelity zones (‘micro-territories’) of workers in the nest, and that (iii) nest architectures promote different queen movement patterns. Besides investigating the feedback between nest architecture and colony organization, our results provide insights into mechanisms of task allocation (worker task choices), since the spatial distributions of workers and brood affect how often different workers are likely to encounter task stimuli (e.g. brood). Our results illuminate the direct proximal influences of the extended phenotype on division of labor in social insects.

Abstract for Lay Audience

Nest architecture in ants is 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. The ant Temnothorax rugatulus provides an ideal model system to investigate the effects of nest architecture on how colonies organize themselves within their nests and environment, thus providing insight into the interactions between these architectures and behavioral expressions. We tested the hypotheses that (i) nest architecture affects ant worker and brood (immature ants) distribution within the nest, in particular (ii) that nest architecture would determine extent and distribution micro-territories of workers in the nest, and that (iii) nest architectures promote different queen ant movement patterns. 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.