This paper deals with the hypothesis, that there is a mechanism in Lasius niger queens giving them the ability to assess the fecundity of another queen, probably through CHC’s. The thorax length likely does not contribute to this mechanism.
Cooperation between unrelated individuals provides benefits that could ensure the survival of species. This work investigates on pleometrotic choosing behavior in Lasius niger ant queens. Here, two or more unrelated and usually monogynous queens found a colony together right after their nuptial flight and cooperate up to the emergence of the first workers.
Then they fight until only one of them remains. Since the surviving queen is usually more fecund and heavier than her former nestmates, it is hypothesized that she will choose smaller queens with a lower fecundity to cooperate with. Therefore, queens in special arenas with two opposite arranged branches were given different choices.
Here, either both branches contained a queen of higher or lower fecundity or only one of them. Two different experiments were performed, where the queens were either grouped random or based on their fecundity. It was found that queens that were chosen over another queen later laid significantly less eggs than the rejected ones.
Additionally, queens that chose a lower fecund queen were significantly faster at choosing than queens that chose a higher fecund one. Queens that chose a queen over an empty nest site also did this faster than queens that chose an empty nest site over a queen. There was no significant difference in thorax length between chosen and rejected queens.
The differences in relative thorax length were only significant in one of two collection locations, where chosen queens were larger than rejected ones.
Table of Contents
1 Abstract
2 Introduction
2.1 Cooperation Between Individuals
2.2 Altruism
2.3 Pleometrosis
2.4 Questions and Hypotheses
3 Material and Methods
3.1 Lasius niger
3.2 Collection and Storing
3.3 Decision Experiments
3.3.1 Random Grouping
3.3.2 Fecundity-based Grouping
3.4 Analysis
4 Results
4.1 The Influence of Fecundity
4.2 The Influence of Size
4.3 The Impact on Choosing Time and Chamber Visits
5 Discussion
5.1 Primary Study Goals
5.2 Fecundity as a Driving Factor in Pleometrotic Choice
5.3 Size does not Matter (mostly)
5.4 All in Good Time
5.5 Evolutionary Aspects
5.6 Error Analysis
5.7 Conclusion
6 Bibliography
Objectives and Research Topics
This work investigates the pleometrotic choosing behavior in Lasius niger ant queens, specifically focusing on whether these queens can assess the fecundity or physical size of potential partners to increase their own evolutionary fitness. The central research question explores whether queens exhibit a preference for partners with specific traits that might influence the outcome of post-emergence competition within a newly founded colony.
- Mechanisms of partner assessment in pleometrotic ant queens
- Influence of queen fecundity on the selection of nesting partners
- Impact of body size (thorax length) on the choice of pleometrotic partners
- Role of decision time and behavior in evaluating potential nest-mates
- Evolutionary fitness advantages associated with selective pleometrosis
Excerpt from the Book
2.3 Pleometrosis
Another, far more specialized kind of cooperation between unrelated individuals is pleometrosis. In social insects in general and Hymenoptera in particular, pleometrosis also shows that this cooperation is not limited to related individuals but also occurs between unrelated conspecifics.
Pleometrosis occurs where two or more unrelated queens of a social insect species found a colony together, even if they are monogynous. In Lasius niger the number of queens is normally reduced to one, shortly after the emergence of the first workers (Hölldobler and Wilson, 1977). Previous research found that in the field 18% of new founded Lasius niger colonies contain two or more queens (Sommer and Hölldobler, 1995).
The main reason why ants enter a pleometrotic association seems to be inter-colony competition. If queens cannot find a suitable nesting site with enough resources, because the density of founding queens and already existing colonies with workers is too high in their area, their probability to die without reproducing is high too (Nonacs, 1992). Older and lager colonies also often brood-raid younger colonies without workers to enlarge their own size (Stamps and Vinson 1991). Pleometrosis reduces the competition for food and other resources between founding queens and provides additional raid security, because pleometrotic colonies produce more workers in a shorter period than single queen colonies.
Summary of Chapters
1 Abstract: Provides an overview of the research investigating Lasius niger queen behavior and the finding that they may possess a mechanism to assess the fecundity of potential partners.
2 Introduction: Establishes the theoretical background regarding eusociality, altruism, and the specific phenomenon of pleometrosis in ants.
3 Material and Methods: Details the experimental design, including collection sites, storage conditions, and the specific setups for the random and fecundity-based decision experiments.
4 Results: Presents the statistical findings regarding the influence of fecundity and size on the choices made by the queens and analyzes the correlation between decision time and behavior.
5 Discussion: Evaluates the experimental findings, interprets the role of fecundity as a driving factor for cooperation, and addresses limitations and potential error sources.
6 Bibliography: Lists the academic sources and references consulted for this study.
Keywords
Lasius niger, pleometrosis, ant queens, fecundity, social evolution, cooperation, decision behavior, thorax length, colony founding, eusociality, reproductive strategy, evolutionary fitness, nest-mate choice
Frequently Asked Questions
What is the core subject of this research?
The research examines the pleometrotic association in Lasius niger, specifically how queens choose their partners when establishing a colony in conditions of high density.
What are the primary themes explored in the study?
The study explores the biological drivers of partner choice, specifically testing the hypotheses that fecundity and body size are key variables influencing the selection process.
What is the main objective of the work?
The primary goal is to determine if queens possess a mechanism to assess the fecundity of potential nest-mates to increase their probability of surviving the aggressive competition that occurs after the first workers emerge.
Which scientific methods were employed?
The author conducted decision experiments using specialized arenas, measured thorax lengths via microscopy, tracked egg-laying rates over several weeks, and performed statistical tests (ANOVA, Fisher’s exact test) to analyze the data.
What is covered in the main section?
The main part details the methodology of the two experiments (random vs. fecundity-based grouping) and presents the results concerning the choices made by the queens under these conditions.
What key concepts define the study?
The study is characterized by concepts such as cooperative colony founding (pleometrosis), reproductive competition, individual fitness optimization, and behavioral assessment mechanisms in ants.
Did the study confirm that size influences queen choice?
No, the findings suggested that thorax length did not significantly influence the choice of a pleometrotic partner in most tested samples.
Why is fecundity considered a critical factor?
Because the queen that survives the post-emergence fight is typically the one with higher reproductive output; therefore, choosing a less fecund partner increases a queen’s competitive edge.
What limitation does the author note regarding the experimental setup?
The author notes that the laboratory conditions were highly artificial, and the small size of the arenas may have influenced the queens' decisions due to density effects.
- Citar trabajo
- Falk Deegener (Autor), 2021, The size and fecundity and the choice of pleometrotic partners in the ant Lasius niger. An analysis of the influence, Múnich, GRIN Verlag, https://www.grin.com/document/1131601
