GROUP COMPOSITION IN SOCIAL SPIDERS: COLLECTIVE BEHAVIOR, KEYSTONE INDIVIDUALS, AND BACTERIAL TRANSMISSION DYNAMICS

The global success of animal societies is due, in part, on the ability of groups of animals to perform collective behaviors that would be unachievable by a single individual. One major determinant of collective behavior is the composition of different types of individuals within the group. For example, individuals often differ consistently in their behavioral traits and the tasks in which they participate, and a group’s composition of individuals expressing different behavioral phenotypes (i.e., “personalities”) can be a fundamental driver of collective behaviors. Though, the same compositions that excel in one aspect of collective behavior may also incur costs in other, opposing patterns of social interactions. Here, I use the social spider Stegodyphus dumicola to test how group personality composition explains patterns of collective behaviors, social interactions, and bacterial transmission. Stegodyphus dumicola is an African social spider that lives in colonies of several dozen to many hundreds of individuals whose collective behaviors are determined by the composition of “bold” and “shy” spiders present in the colony. I found that group personality composition is a more important predictor of the execution of collective behaviors than more conspicuous colony traits like group size. Then, using social network analyses I found that colony contact networks are disassortive, where individuals preferentially interact with others of opposing personality types. Using experimental exposures to a fluorescence-transformed cuticular bacterium (Pantoea sp.), I found that horizontal bacterial transmission is predominantly directional, occurring more so from “bolder” to “shyer” spiders. Thus, it could be reasoned that animal groups containing diverse personality types may experience augmented success during collective tasks, but may also incur costs in the context of horizontal bacterial transmission. Taken together, it appears that personality compositions may impose constraints on the social organization of animal societies

The emerging field of venom-microbiomics for exploring venom as a microenvironment, and the corresponding Initiative for Venom Associated Microbes and Parasites (iVAMP)

Venom is a known source of novel antimicrobial natural products. The substantial, increasing number of these discoveries have unintentionally culminated in the misconception that venom and venom-producing glands are largely sterile environments. Culture-dependent and -independent studies on the microbial communities in venom microenvironments reveal the presence of archaea, algae, bacteria, endoparasites, fungi, protozoa, and viruses. Venom-centric microbiome studies are relatively sparse to date and the adaptive advantages that venom-associated microbes might offer to their hosts, or that hosts might provide to venom-associated microbes, remain unknown. We highlight the potential for the discovery of venom-microbiomes within the adaptive landscape of venom systems. The considerable number of known, convergently evolved venomous animals juxtaposed with the comparatively few studies to identify microbial communities in venom provides new possibilities for both biodiversity and therapeutic discoveries. We present an evidence-based argument for integrating microbiology as part of venomics to which we refer to as venom-microbiomics. We also introduce iVAMP, the Initiative for Venom Associated Microbes and Parasites (https://ivamp-consortium.github.io/), as a growing consortium for interested parties to contribute and collaborate within this subdiscipline. Our consortium seeks to support diversity, inclusion and scientific collaboration among all researchers interested in this subdiscipline

Data from: Personality composition is more important than group size in determining collective foraging behaviour in the wild

Describing the factors that shape collective behaviour is central to our understanding of animal societies. Countless studies have demonstrated an effect of group size in the emergence of collective behaviours, but comparatively few have accounted for the composition/diversity of behavioural phenotypes, which is often conflated with group size. Here, we simultaneously examine the effect of personality composition and group size on nest architecture and collective foraging aggressiveness in the social spider Stegodyphus dumicola. We created colonies of two different sizes (10 or 30 individuals) and four compositions of boldness (all bold, all shy, mixed bold and shy, or average individuals) in the field and then measured their collective behaviour. Larger colonies produced bigger capture webs, while colonies containing a higher proportion of bold individuals responded to and attacked prey more rapidly. The number of attackers during collective foraging was determined jointly by composition and size, although composition had an effect size more than twice that of colony size: our results suggest that colonies of just 10 bold spiders would attack prey with as many attackers as colonies of 110 ‘average’ spiders. Thus, personality composition is a more potent (albeit more cryptic) determinant of collective foraging in these societies

Submersion tolerance in a lakeshore population of Pardosa lapidicina (Araneae: Lycosidae)

Volume: 42Start Page: 192End Page: 19

Keiser and Pruitt - Composition and size ESM

The data associated with collective behavior assays. Three response variables (latency to emerge from the colony retreat, latency to attack the prey stimulus, number of attackers) in response to two independent variables: colony personality composition and colony size