Dr. Susanne Foitzik
- Curriculum Vitae
- Research Interests
- Genome-wide detection of selection and adaptation in a co-evolving slavemaking ant and its host
- Ultimate and proximate aspects of spatial learning in an individually foraging social insect
- The role of gene regulation in the division of labour in ants
- Parasite interference in regulation of host gene expression
- Machine-learning prediction of Odorant Receptor ligand interactions
- Functional basis of the fecundity - longevity reversal in the ant Temnothorax rugatulus
- Reversal of the fecundity / longevity trade-off across social transitions in ants
- The molecular basis of social information-use in honeybees (Apis mellifera)
- Comparative genomics of slave-making ants and their hosts
Academic and Research Appointments
Professor in Evolutionary Biology (W 3), Johannes Gutenberg University Mainz, 2010-
Professor in Behavioral Ecology (C 3), LMU Munich, 2004-2010
Assistant Professor in Zoology (C1), University of Regensburg, 2000-2004
Postdoctoral Fellow, Colorado State University, Ft. Collins, USA, 1998-2000
Habilitation, Zoology, University of Regensburg 2004
Dr. rer. nat., Biology, Julius Maximilians University Würzburg 1998
Diploma, Biology, Julius Maximilians University Würzburg 1995
Honors and Awards
Speaker, Research training Group 2626 GenEvo: Gene Regulation in Evolution 2019-
Speaker, EES Master Program, financed by the VW foundation, 2007-2010
DAAD Fellow, State University of New York, Albany USA, 1992-93
Academic and Professional Service
Vice-Dean of the Faculty of Biology, JGU Mainz 2017-
Acting director of the Institute of Organismic and Molecular Evolution (IOME) JGU Mainz 2017-
Member of the Faculty committee and the Senate, JGU Mainz, 2014-
Member of the Gutenberg Council for Young Researchers, JGU Mainz, 2014-
Member of the DFG Review board Zoology 2012-2016
Member of the Senate Evaluation Committee of the Leibniz Association 2011-2015
Academic and Professional Service
Handling Editor Biology Letters 2016-
Editorial Board Insectes Sociaux 2006-2014
I am interested in the evolution of social behaviour taking an integrative approach from behavioural ecology over genomics to epigenetics. We focus on ants and occasionally on bees as model organisms as behaviours of these social animals are selected on different levels, are highly complex and include cooperation as well as conflict. We investigate the role of plasticity to generate different phenotypes via differential gene expression. We study the evolution of life history strategies, aging and genomes of social insects. We are interested in how parasites affect and manipulate social insects and whether and how hosts can defend themselves against these attacks.
Currently, we focus on the following research questions:
- How do insect societies defend themselves against parasites?
- Which traits and genes are under selection in host-parasite coevolution?
- How did slavemaking behaviour in ants evolve and coevolve with their hosts?
- How do insect societies regulate division of labour and allow specialization?
- What is the evolutionary importance of variance in behaviour and other traits?
- Which fitness advantages have different behavioural strategies in social insects?
- How is it possible that ant queens can live for several decades?
- How is aging and fecundity regulated on a molecular level?
- What are the molecular underpinnings of learning and memory?
- Which gene regulatory processes are involved in phenotypic plasticity in social insects?
Genome-wide detection of selection and adaptation in a co-evolving slavemaking ant and its host
Funded by DFG
in cooperation with Dr. Barbara Feldmeyer, BiK F Senckenberg, Frankfurt
PhD Students: Erwann Collin and Maide Macit
Coevolution between antagonistic species can drive evolutionary arms races - reciprocal cycles of coadaptation. Recent advances in sequencing technologies allow now to study the molecular basis of evolutionary adaptations on a genomic level in non-model systems. In this project, we focus on a well-studied host-parasite system consisting of the slavemaking ant Temnothorax americanus, an obligate social parasite, and its related host Temnothorax longispinosus, for which ample evidence for coevolution and local adaptation exists. We have used transcriptomics to investigate, which genes underlie slave raiding and host defence behavior in three slavemaking ants and their three host species of the genus Temnothorax. We detected candidate genes upregulated during slave raids and under selection. First RNAi experiments revealed their potential function in controlling raiding behaviors. We found little overlap between species, both among the differentially expressed genes and those under selection, indicating species-specific evolutionary trajectories. A first population-level project demonstrated that host responses and brain gene expression depends on slavemaker origin, that is parasite prevalence of the slavemaker population. We are now going a step further and investigate the molecular basis of coevolution on a genome-wide level. This is possible as we recently obtained and annotated the genomes of our two main model species. We use populations of a “natural experiment”, in which host and parasite evolve in sympatry (=coevolve) or allopatry. We are studying the genetic background of adaptations, the types and strength of selection and whether mainly regulatory regions or protein-coding genes are important for coadaptation. We use a combination approach of genome-wide Pool-Seq and Resequencing ant genomes from 12 host and 8 parasite populations to determine genes and regions under selection and linkage. We characterize chemical traits (cuticular hydrocarbons and Dufour gland secretions) and tissue-specific gene expression of all populations to be able conduct a genome-wide association study and link the genomic information to chemical, transcriptomic and behavioural phenotypes. By analysing multiple populations under similar selective regimes, we can reveal whether coevolution takes different avenues in different locales or whether it occurs in parallel. Once we have identified interesting candidate loci, we conduct functional RNAi analyses to characterize their effect on the phenotype experimentally. Overall, our study contributes to a better understanding of genetic mechanisms of adaptation during coevolution.
The slavemaking ant Temnothorax americanus (left) is interacting with a Temnothorax longispinosus host worker (right)
Ultimate and proximate aspects of spatial learning in an individually foraging social insect
Funded by DFG
in cooperation with Prof. Dr. Inon Scharf, Tel Aviv University and Dr. Romain Libbrecht, JGU Mainz
Learning, the process of altering one’s behaviour following experience, is a common process animals undergo. Learning can increase the performance of various activities and consequently the fitness of an animal. This multidisciplinary proposal focuses on the triple link between learning, forgetting and gene expression, which is a rarely studied combination. We do so in the context of foraging behaviour. Learning is expected while foraging, because animals regularly search for food and need to adjust their behaviour. We have identified several gaps in the current literature, which we plan to fill by studying: (1) the proximate molecular mechanisms that underlie learning processes; (2) forgetting, in particular, the adaptive loss of information, which can be as important as learning but is less often studied; and (3) the adaptive value of spatial learning under competitive conditions. Although competition is a main factor driving ecological and evolutionary processes, the value of learning has not been tested under competitive conditions with naive individuals. We propose to explore all these aspects in an individually foraging ant, Cataglyphis niger. We have already shown that C. niger colonies learn to solve a maze and remember this spatial information for over two weeks. Moreover, we used transcriptomics and epigenetic inhibitors intensely to investigate gene expression and gene regulatory processes underlying different behaviours in ants. We propose here a series of experiments to analyse (1) which changes in gene expression, histone modifications and DNA methylation are associated with learning and forgetting. We expect that inhibiting relevant epigenetic processes impair learning and may lead to faster forgetting. (2) The behavioural mechanism of forgetting, whether it is a passive process (decay), or an active one, involving either retroactive or proactive interferences, i.e., either that learning new information could interfere with memory, or that prior information interferes with acquiring new information. (3) the interactive effect of colony size and learning on foraging success under competition conditions. We suggest that smaller colonies can outcompete larger ones, given sufficient learning ability and spatial information to find the food resources. Our findings are interest to researchers from various fields – from behavioural ecology, through experimental psychology to molecular neurobiology.
The role of gene regulation in the division of labour in ants
Funded by DFG within RTG 2526 GenEvo
in cooperation with Prof. Dr. Peter Baumann and Prof. Dr. Susanne Gerber, JGU Mainz
PhD Student: Marcel Caminer
Social insects are models for the evolution of phenotypic plasticity as variation in gene expression largely controls caste development. Social insect workers specialise in specific tasks and this division of labour is thought to contribute to the ecological success of insect societies. Task specialisation is mostly neither genetically determined nor rigid, but changes with age and in response to colony needs. Typically, young workers takeover brood care, whereas older workers focus on risky external tasks such as foraging. Indeed (i) the expression of behavioural genes shifts with the tasks of workers and (ii) histone acetylation can regulate task-specific gene expression. Our hypothesis is that additional gene regulatory mechanisms, such as histone or DNA methylation are involved and may interact in regulating division of labour. We also aim to understand how all of these regulatory processes respond to external cues, the expression of which genes they alter and how fast they can change gene expression. Previously, we analysed division of labour, the expression and functions of task-specific genes, and the importance of histone-acetylation for their expression in the ant Temnothorax longispinosus. Theory posits that task switching requires shifts in responsiveness to task-related cues and indeed, we identified a gene, vitellogenin-like A (vg-like A) that regulates task allocation and social cue responsiveness: Once knocked down by RNAi, young workers reduce brood- but increase nestmate care, a behaviour usually exhibited by older workers. This behavioural change was accompanied by a vg-like A-dependent shift in worker responsiveness from brood to adult worker cues. An experimental set-up allowed us to disentangle task from age and the following transcriptome analysis resulted in four times more genes linked to task than to age. Finally, the administration of the histone acetyltransferase (HAT) inhibitor C646 impeded the switch of foragers back to brood care, but promoted the reversed change from brood care to foraging. HAT inhibition did not affect workers continuing to execute the same tasks, pointing to the role of histone acetyltransferase in altering gene expression. HAT activity keeps young workers in a “brood caring mode”, possibly to prevent them from leaving the nest prematurely. We are currently using ChipSeq analyses identifying genes associated with de-acetylated histones due to inhibition of C646 and we are analysing the associated changes in gene expression. In this project, we deepen our understanding of the regulation of division of labour in social insects by a) experimentally influencing gene regulation using various epigenetic inhibitors, followed up by a behavioural readout and Chip-, RNA and ATAC Seq-analyses, to link the behavioural phenotype to gene expression and regulatory mechanisms e.g. splicing, b) studying RNA and DNA methylation in the brain by reduced representation bisulfite sequencing, c) Investigating which brain neuropils are responsible for behavioural changes (e.g. mushroom body, antennal lobes).
Colonies of the ant Temnothorax longispinosus with queens in the centre.
Parasite interference in regulation of host gene expression
Funded by DFG within RTG 2526 GenEvo
in cooperation with Prof. Dr. Peter Baumann, JGU and Dr. Falk Butter, IMB
PhD Student: Tom Sistermans
The Extended phenotype concept (Dawkins, 1982) states that genes do not only affect the phenotype of their carrier, but also alter the latter’s biotic and abiotic environment. Especially parasites with complex life cycles manipulate the behaviour of their intermediate hosts to increase transmission to the definite host, ranging from alterations in pre-existing traits to the display of novel behaviours. Alterations in host gene expression are often associated with parasite-induced phenotypic changes. We hypothesise that parasites manipulate host phenotypes to increase transmission by interfering with host gene regulation and are interested in which gene regulatory processes are affected. Infection of Temnothorax nylanderi ant larvae with the parasitic cestode Anomotaenia brevis strongly alters the adult phenotype. Parasitized workers exhibit altered behaviour, morphology, chemical profile and a lifespan extension. We could show associated changes in gene expression e.g. the upregulation of longevity genes. This pointed to an improved ability of infected workers to deal with oxidative stress, which was supported by experiments with paraquat. The cestode, residing in its cysticercoid stage in the ants’ gaster is transcriptionally active and releases many proteins into the host. In collaboration with Falk Butter, we compared the proteome of the haemolymph of healthy workers and infected workers and contrasted it with that of the cestode. The vast majority of proteins that were only found in infected workers originated from the cestode. Bioinformatic analyses are on-going to identify protein functions and to elucidate their role in gene expression interference. To demonstrate that parasite-induced changes in host phenotype are actively promoted by the parasite, we will investigate how the cestode parasite interferes with the hosts’ gene regulation, which gene-regulatory mechanisms are utilised and whether these alterations are permanent or have to be actively maintained. We do this by a) further investigating the cestode transcriptome to identify manipulative transcription modifiers (transcription factors, epigenetic regulators) and to test whether they are released into the host, b) Conduct an in-depth bioinformatic analysis of the proteome of the parasite and the haemolymph of infected / uninfected workers to identify released proteins and thereafter inject them in healthy workers to investigate their function, c) Study histone modifications and DNA methylation associated with parasite infection and link them to observed gene expression changes d) Contrasting the transcriptome during different developmental stages / body parts of infected / uninfected ants as infection occurs during the larval stage, d) Clear infection using antihelminthics and analyse changes in the phenotype, including gene expression and regulation and e) Phenotype host and cestode candidate genes using RNAi.
Worker of the ant Temnothorax nylanderi (right) infected with the cestode Anomotaenia brevis, compared to an uninfected worker (left). Cysticercoid larvae of the cestode Anomotaenia brevis (Photo: Benjamin Weiss)
Machine-learning prediction of Odorant Receptor ligand interactions
Funded by the Emergent AI Center of the Carl-Zeiss Foundation
In cooperation with Prof. Miguel Andrade, Dr. Romain Libbrecht, Dr. Carlotta Martelli, JGU Mainz
PhD Student Marah Stoldt
Biology is full of examples where evolution has led to the emergence of intelligent systems in a wide range of complexities of which the human brains is only one extreme. However, while the study of the brain is undoubtedly of importance to learn about the emergence of intelligence and consciousness, its complexity with about 100 billion neurons can hinder our ability to study early steps of intelligence evolution. Interestingly, during evolution also other intelligent systems evolved. In this project, we propose to focus on the evolutionary emergence of cognition in insect societies. Interactions of social insects, some of which form colonies that may contain 300 million individuals, are no less complex and adaptable than nervous systems: insects offer an alternative approach to the study of the emergence of intelligent biological systems. Of them, 15,000 alone are ants, which display great variation in their social organizations and colony complexities. Most insects live in a chemical world, so that olfactory receptors (ORs) play an important molecular role in perception, cognition and communication. Ants communicate within their colonies via chemical signals and evolved a large and novel clade of odorant receptor (OR) genes. These proteins bind chemicals to trigger a neural reaction (sensory perception). In a single ant species, up to 400 different OR genes can occur, which form a protein family and have arisen during the evolution of sociality by gene duplication. The evolution of the OR family is very dynamic. Duplicated genes likely specialize in adapting their binding sites for the detection of new molecules (neofunctionalization), which itself increases the sensorial functions of the species holding the duplicated gene. Deletions of ORs are also known to happen. For example, social parasites, ants, which lost their social lifestyle, are characterized by a large loss of odorant receptor genes, providing further evidence that OR evolution is tightly linked to sociality. Expansions and contractions of the OR family thus relate to the social and behavioral features of ant species. Yet, which particular molecular odorant molecule a specific OR targets in a certain species is largely unknown. Indeed, we know little about the specific functions of each OR. Partial information exists for a few ORs in a few ant species, and also for the corresponding ORs in other non-ant insect species. In particular, the fruit fly Drosophila melanogaster as a (non-social) model species has a fair number of characterized ORs. D. melanogaster thus offers a very interesting contrast with molecular information and possibilities for experimental testing. Unfortunately, even for the well-studied D. melanogaster, the functional characterization of its ORs is incomplete: the development of methods to find a relation between the protein sequences of a family and their molecular targets is necessary to advance our knowledge and research on the function of the OR family. We adapt machine learning methods for this task since we face a prediction task where the number of biological features is relatively small, features are heterogeneous and of unknown contribution, and the set of training data is limited. We overcome this shortcoming by coding the molecular and behavioral features with the highest possible precision.
Functional basis of the fecundity - longevity reversal in the ant Temnothorax rugatulus
Funded by DFG within Research Unit 2281
in cooperation with Dr. Barbara Feldmeyer, BiK F Senckenberg, Frankfurt
PhD Student: Marina Choppin
Social insect queens exhibit extraordinarily long lifespans and are highly fecund. In most other animals, these two life history traits are traded-off, that is individuals that invest a lot in reproduction pay the price of reduced longevity. Projects in our research unit aim at gaining a deeper understanding of the ultimate and proximate basis of this longevity/fecundity reversal. Here we focus on the ant Temnothorax rugatulus, where we could show that an experimental fertility induction in workers resulted in a life-span extension indicating that the two life history traits are positively linked even within each caste. The smaller microgyne queens can maintain the same fecundity due to a higher metabolic rate, but are unable to increase egg-laying rates following egg removal. However, the larger macrogynes can increase their fecundity when eggs are removed and we are currently analysing how this affects gene expression. A completed transcriptome analyses contrasting brain versus fat body of young and old queens, which also differed strongly in fecundity, revealed the importance of several longevity genes and pointed to well-known longevity pathways, such as Toll and TOR signalling. We are currently elucidating the functional basis of the fecundity and longevity reversal in this ant, by analysing the regulation and connectivity of candidate genes in gene regulatory pathways. We conduct a number of experimental manipulations using RNAi to demonstrate causal relationships between different genes and pathways and to reveal the effect of candidate genes on queen and worker fecundity and longevity. Moreover, we study epigenetic mechanisms regulating expression in these pathways by experimentally inhibiting histone (de-)acetylation and DNA methylation. Thereafter, we do not only analyse how these manipulations affect the ability of queens and workers to change their fecundity, but we are following up with ChipSeq, Bisulfite sequencing, and RNA seq to directly check how these epigenetic processes and in turn gene regulation was affected. Our results indicate an influence of diet and in particular of the protein content on ant fecundity and longevity. Our project addresses several levels and focusses on the two most divergent female castes, workers and macrogynes. Our project will thus contribute to the understanding of the proximate mechanisms and the ultimate factors that lead to the fecundity/ longevity reversal in social insects.
Macrogyne (left) and microgyne (right) queen of the ant Temnothorax rugatulus
(Photo Romain Libbrecht)
Reversal of the fecundity / longevity trade-off across social transitions in ants
Funded by DFG within Research Unit 2281
in cooperation with Dr. Volker Nehring, Univ. Freiburg and Dr. Romain Libbrecht, JGU Mainz
PhD Student: Megha Majoe
Investigation of the reversal of the fecundity/longevity trade-off in social insects are providing important insights into the modulation of senescence. So far, studies have failed to find common molecular regulators of ageing across the social insects, possibly because uncontrolled ecological variation between the typical study species covered key factors regulating ageing. We tackle this problem by using a comparative approach focussed on ants, to identify senescence regulators that are independent of any model species' specific ecology or phylogenetic position. In most ants, workers can produce haploid males. They usually do so when the queen dies, to gain direct fitness. However, workers typically cannot fully replace the queen because they lack the ability to produce diploid queens and workers. Interestingly, two alternative worker types have evolved repeatedly in ants: totipotent workers that can produce both males and females, and sterile workers that cannot produce any viable offspring. In addition to these physiological constraints, a worker's chance for direct reproduction also depends on colony-level life-history parameters, such as colony size and queen number, which should further affect worker-ageing mechanisms. We investigate how caste (queen or worker), fecundity (egg-laying or not), and age (young or old) affect gene expression in 15 species of ants. We carefully selected species with varying colony size and queen number, to quantify the effect of worker reproductive potential on senescence independent of species ecology and phylogenetic position. Two factors that prolong lives in many species are the resilience to oxidative stress and pathogen exposure. It has been proposed that social insect queens live longer because workers protect them against these environmental stressors and/or provide them with enough resources to maintain active repair and defence mechanisms. We experimentally investigate whether ant workers with different reproductive potential (across and within 15 species) also differ in their resilience to oxidative stress and immune challenge. Overall, this comparative project across 15 ant species provides insights into the molecular and physiological mechanisms underlying ageing in ants, how fecundity is linked to longevity in both queens and workers, and our general understanding of the reversal of the fecundity/longevity trade-off on the background of transitions in advanced social evolution.
Colony of the ant Temnothorax rugatulus with queen in center (Photo: Romain Libbrecht)
The molecular basis of social information-use in honeybees (Apis mellifera)
Funded by DFG
in cooperation with Dr. Christoph Grüter, Univ. Bristol, UK
PhD Student: Anissa Kennedy
Learning from others, i.e. social learning, is widespread in nature and helps animals to acquire locally adaptive information. Yet, while social learning can provide a low-cost, low-risk strategy of acquiring information, it is also prone to obtaining outdated, unreliable and even maladaptive information. As a consequence, animals often only use social learning when this is the best strategy. Honeybees possess one of the most sophisticated forms of social learning in the animal world, the waggle dance. As is the case in other animals, some bees ignore this social information and instead rely on so-called private information (i.e. spatial memories) or individual exploration (i.e. scouting) when searching for food. While the ecology and economy of social learning has received much attention, little is known about the molecular and neural basis of social learning. The advent of genomics has revolutionised the study of behaviour and we are now able to measure the expression of thousands of genes in specific areas of the brain to better understand the molecular basis of social behaviours. The aim of this project is to test if different information-use strategies (social learning vs. private information-use vs. individual exploration) can be linked to particular gene expression signatures in two important areas of the insect brain, the mushroom bodies (MB) and the antennal lobes (AL). More specifically, we plan to address four questions: (1) is the reliance on social learning, i.e. the decoding of waggle dances, associated with a characteristic neurogenomic signature? (2) In particular, are genes that mediate reward perception causally responsible for the use of social learning? (3) Does the successful use of social learning affect gene expression differentially than the use of private information? (4) Are differences in the use of social vs. private information consistent over time? One hypothesis of the project is that genes involved in reward perception and motivation (e.g. octopamine, dopamine, catecholamine, glutamate signalling) are important in mediating social learning. We will address these four questions by combining behavioural experiments, next-generation sequencing technology and neurochemical treatments (biogenic amines and RNA interference) to study social learning in honeybees. Honeybees are an ideal model system to due to their easily studied waggle dances, their accessibility to experimentation and the availability of a well annotated genome. The findings from this project are likely to provide insights into the molecular basis of this unique form of communication, but also reveal more general neural processes involved in social learning.
Honey bee (Apis mellifera) worker on a foraging trip
Comparative genomics of slave-making ants and their hosts
Funded by DFG
in cooperation with Prof. Dr. Erich Bornberg-Bauer, Univ. Münster, Prof. Dr. Jürgen Heinze, Univ. Regensburg, Dr. Barbara Feldmeyer, Bik-F Senckenburg, Frankfurt
Aim of the project is to detect genomic traces of the parallel evolution of one of the most bizarre life histories of social insects, slave-making in ants. Workers of slave-making ants pillage brood from the nests of closely related ant species, which after emergence serve as slaves in the slave-maker colony. Given that evolution across different time scales involves different genomic mechanisms, we will test for possible signals of adaptation to slave-making at the levels of gene regulation, coding sequences, and gene or domain losses, gains and rearrangements. To do so we will compare the genomes of three related, but convergently evolved slave-making ants with the genomes of two of their host species. To increase the statistical power, these data will be complemented by data from an ongoing genome analysis in an additional pair of slave-makers and hosts and transcriptomes from additional slave-makers, hosts, and two related species, which are not exploited by social parasites.
Worker of the slavemaking ant Temnothorax americanus (left) interacts with enslaved ant worker of the species Temnothorax longispinosus (Photo Romain Libbrecht).
Foitzik S., Fritsche O. (2021) Empire of Ants: The Hidden Worlds and Extraordinary Lives of Earth's Tiny Conquerors. The Experiment, New York, USA
125 Publications in peer-reviewed journals
2021 / in press
Gilad, T., Dorfman A., Subach A., Libbrecht, R., Foitzik, S., Scharf S. Evidence for the effect of brief exposure to food, but not learning interference, on maze solving in desert ants. Integrative Zoology, in press.
Jongepier, E., Séguret, A., Labutin, A., Feldmeyer, B. Gstöttl, C., Foitzik, S., Heinze. J., Bornberg-Bauer, E. Convergent loss of chemoreceptors across independent origins of slave-making in ants. Molecular Biology and Evolution, msab305, https://doi.org/10.1093/molbev/msab305
Choppin, M., Feldmeyer, B., Foitzik, S. (2021) Histone acetylation regulates the expression of genes involved in worker reproduction in the ant Temnothorax rugatulus. BMC Genomics, 22:871; https://doi.org/10.1186/s12864-021-08196-8
Beros, S., Lenhart, A., Scharf, I., Negroni, M.N., Menzel, F., Foitzik, S. (2021) Extreme lifespan extension in tapeworm-infected ant workers. Royal Society Open Science, 8(5):202118; DOI: 1098/rsos.202118
Scharf, I., Stoldt, M., Libbrecht, R., Höpfner, A.L., Jongepier, E., Kever, M., Foitzik, S. (2021) Social isolation causes downregulation of immune and stress response genes and behavioral changes in a social insect. Molecular Ecology, 30(10):2378-2389; doi: 10.1111/mec.15902
Kennedy, A., Peng, T., Glaser S.M., Linn, M., Foitzik, S., Grüter, C. (2021) Use of waggle dance information in honey bees is linked to gene expression in the antennae, but not in the brain. Molecular Ecology, 30(11):2676-2688. doi: 10.1111/mec.15893
Negroni, M.A; Stoldt, M., Oster, M., Rupp, A-S., Feldmeyer, B. Foitzik, S. Social organisation and the evolution of life-history traits in two queen morphs of the ant Temnothorax rugatulus. Journal of Experimental Biology, in press. DOI: 1242/jeb.232793
Negroni, M.A., Macit, M.N., Stoldt, M., Feldmeyer, B. Foitzik, S. (2021) Molecular regulation of lifespan extension in fertile ant workers. Philosophical Transactions of the Royal Society B 376: 20190736. DOI: 1098/rstb.2019.0736
Majoe, M., Libbrecht, R., Foitzik, S. Nehring, V. (2021) Queenloss increases worker survival in leaf-cutting ants under paraquat-induced oxidative stress. Philosophical Transactions of the Royal Society B. 376: 20190735. DOI: 10.1098/rstb.2019.0735
Korb, J., Meusemann, K., Aumer, D., Bernadou, A., Elsner, D., Feldmeyer, B., Foitzik, S., Heinze, J., Libbrecht, R., Lin, S., Majoe, M., Kuhn M.M., Nehring, V., Negroni, M., Paxton, R.J., Séguret, A.C., Stoldt, M., Flatt T., & So-Long consortium (2021) Comparative transcriptomic analysis of the mechanisms underpinning ageing and fecundity in social insects. Philosophical Transactions of the Royal Society B, 376: 20190728. DOI: 10.1098/rstb.2019.0728
Negroni, M.A., Feldmeyer, B., Foitzik, S. (2021) Experimental increase in fecundity causes upregulation of fecundity and body maintenance genes in the fat body of ant queens. Biology Letters 17: 20200909. DOI: 10.1098/rsbl.2020.0909
Choppin, M., Graf, S., Feldmeyer, B., Libbrecht, R., Menzel, F., Foitzik, S. (2021) Queen and worker phenotypic traits are associated with colony composition and environment in Temnothorax rugatulus (Hymenoptera: Formicidae), an ant with alternative reproductive strategies. Myrmecological News, 31: 61-69, DOI: 10.25849/myrmecol.news_031:061
Stoldt, M., Klein, L., Beros S., Butter, F., Jongepier, E., Feldmeyer B., Foitzik, S. (2021) Parasite presence induces gene expression changes in an ant host and their function in immunity and longevity. Genes, 12: 95
Negroni, M.A., Segers, F., Vogelweith F, Foitzik, S. (2020) Immune challenge reduces gut microbial diversity and triggers fertility-dependent gene expression changes in a social insect. BMC Genomics, 21:816, DOI: 10.1186/s12864-020-07191-9
Körner M, Vogelweith F, Libbrecht R, Foitzik S, Feldmeyer B, Meunier J. (2020) Offspring reverse transcriptome responses to maternal deprivation when reared with pathogens in an insect with facultative family life. Proceedings of the Royal Society B, 287: 20200440, DOI: 1098/rspb.2020.0440
Gstöttl C, Stoldt M, Jongepier E, Bornberg-Bauer E, Feldmeyer B, Heinze H, Foitzik S. (2020) Comparative analyses of caste, sex and developmental stage-specific transcriptomes in two Temnothorax Ecology and Evolution, 10:4193–4203, DOI: 10.1002/ece3.6187
Libbrecht, R, Nadrau D., Foitzik, S. (2020) A role of histone acetylation in the regulation of circadian rhythm in ants. IScience, 23: 100846, DOI: 1016/j.isci.2020.100846
Segers, F., Kaltenpoth, M., Foitzik, S. (2019) Abdominal microbial communities in ants depend on colony membership rather than caste and are linked to colony productivity. Ecology and Evolution, 9: 13450-13467.
Segev U, Foitzik S (2019). Ant personalities and behavioral plasticity along a climatic gradient. Behavioral Ecology and Sociobiology, 73:84
Alleman A, Stoldt M, Feldmeyer B, Foitzik S (2019) Tandem-Running and Scouting Behavior is Characterized by Up-Regulation of Learning and Memory Formation Genes within the Ant Brain. Molecular Ecology 28: 2342-2359
Negroni, M.A., Foitzik, S., Feldmeyer, B. (2019) Long-lived Temnothorax ant queens switch from investment in immunity to antioxidant production with age. Scientific reports 9, 7270.
Kaur, R., Stoldt, M., Jongepier E., Feldmeyer, B, Menzel, F., Bornberg-Baur, E., Foitzik, S. (2019). Ant behaviour and brain gene expression of defending hosts depend on the ecological success of the intruding social parasite. Philosophical Transactions of the Royal Society B: 374: 1769
Kohlmeier, P., Alleman, A., Libbrecht, R., Foitzik S.* Feldmeyer, B.*, (2019) Gene expression is more strongly associated with behavioural specialisation than with age or fertility in ant workers. Molecular Ecology, 28: 658-670 *shared last author
Beros, S., Enders, C., Menzel, F., Foitzik, S. (2019) Parasitism and queen presence interactively shape worker behaviour and fertility in an ant host. Animal Behavior 148: 63-70
Grüter, C., Jongepier, E., Foitzik, S. (2018) Insect societies fight back: the evolution of defensive traits against social parasites. Philosophical Transactions of the Royal Society B, 373
Kohlmeier, P., Feldmeyer, B., Foitzik S. (2018) Vitellogenin-like A - associated shifts in social cue responsiveness regulate behavioral task specialization in an ant. Plos Biology, 16(6): e2005747
Körner M., Foitzik S., Meunier J. 2018. Extended winters entail long-term costs for insect offspring reared in an overwinter burrow. Journal of Thermal Biology, 74: 116-122.
Alleman, A., Feldmeyer, B., Foitzik, S. (2018) Comparative analyses of co-evolving host-parasite associations reveal unique gene expression patterns underlying slavemaker raiding and host defensive phenotypes. Scientific Reports 8: 1951
Feldmeyer, B., Elsner, D. Alleman, A., Foitzik S. (2017) Species-specific genes under selection characterize the co-evolution of slavemaker and host lifestyles. BMC Evolutionary Biology, 17:237.
Beros, S. Foitzik, S., Menzel, F. (2017) What are the Mechanisms Behind a Parasite-Induced Declin,e in Nestmate Recognition in Ants? Journal of Chemical Ecology, 43(9):869-880.
Vogelweith, F., Foitzik, S., Meunier, J. 2017. Age, sex, mating status, but not social isolation interact to shape basal immunity in a group-living insect. Journal of Insect Physiology, 103: 64-70.
Körner M, Vogelweith F, Foitzik S, Meunier J. 2017. Condition-dependent trade-off between weapon size and immunity in males of the European Earwig. Scientific Reports, 7 (1): 7988.
Segev U, Burkert L, Feldmeyer B, Foitzik, S. 2017. Pace-of-life in a social insect: behavioral syndromes in ants shift along a climatic gradient. Behavioral Ecology, 28: 1149-1159.
Vogelweith F, Körner M, Foitzik S und Meunier J. 2017. Age, pathogen exposure, but not maternal care shape offspring immunity in an insect with facultative family life. BMC Evolutionary Biology, 17:69.
Kohlmeier P, Negroni M, Kever M, Emmling S, Stypa H, Feldmeyer B und Foitzik S. 2017. Intrinsic worker mortality depends on behavioural caste and the queens' presence in a social insect. The Science of Nature, 104: 34.
Kleeberg I, Menzel F and Foitzik S. 2017. The influence of slavemaking lifestyle, caste and sex on chemical profiles in Temnothorax ants: Insights into the evolution of cuticular hydrocarbons. Proceedings of the Royal Society B, 284: 1850.
Menzel F, Radke R, Foitzik S. 2016. Odor diversity decreases with inbreeding in the ant Hypoponera opacior. Evolution, 70: 2573-2582.
Negroni M, Jongepier E, Feldmeyer B, Kramer BH, Foitzik S. 2016. Life History Evolution in social insects: a female perspective. Current Opinion in Insect Science, 16: 51–57.
Metzler D, Jordan F, Pamminger T, Foitzik S. 2016. The inﬂuence of space and time on the evolution of altruistic defense: the case of ant slave rebellion. Journal of Evolutionary Biology, 29: 874-886.
Jongepier E, Foitzik S. 2016. Ant recognition cue diversity is higher in the presence of slavemaker ants. Behavioural Ecology, 27: 304–311.
Feldmeyer, B, Mazur J, Beros S, Lerp H, Binder H, Foitzik S. 2016. Gene expression patterns underlying parasite-induced alterations in host behaviour and life history. Molecular Ecology, 25: 648–660.
Jongepier E, Foitzik S. 2016. Fitness Costs of Worker Specialisation for Ant Societies. Proceedings of the Royal Society B, 283: 1822.
Kleeberg I, Foitzik S. 2016. The placid slavemaker: avoiding detection and conflict as an alternative, peaceful raiding strategy. Behavioral Ecology and Sociobiology 70: 27-39.
Beros S, Jongepier E, Hagemeier F, Foitzik S. 2015. A parasite’s long arm: a tapeworm parasite induces behavioural changes in uninfected group members of its social host. Proceedings of the Royal Society B, 282: 1819.
Jongepier E, Kleeberg I, Foitzik S. 2015. The ecological success of a social parasite increases with manipulation of collective host behaviour. Journal of Evolutionary Biology, 28: 2152–2162.
Kleeberg, I., Jongepier, E., Job S. & Foitzik, S. 2015. Geographic variation in social parasite pressure predicts intra- but not interspecific aggressive responses in hosts of a slavemaking ant. Ethology, 121: 1-9.
Pamminger, T., Foitzik, S., Metzler, D., Pennings P.S. 2014. Oh sister, where art thou? Spatial population structure and the evolution of an altruistic defence trait. Journal of Evolutionary Biology 27: 2443-2456.
Jongepier, E., Kleeberg, I., Job S. & Foitzik, S. 2014 Collective defense portfolios of ant hosts shift with social parasite pressure. Proceedings of the Royal Society B, 281: 1791
Kleeberg, I., Pamminger T., Jongepier, E., Papenhagen, M. & Foitzik, S.2014 Forewarned is forearmed: Aggression and information use determine fitness costs of slave raids. Behavioral Ecology, 25 (5): 1058-1063.
Kühbandner S, Modlmeier A., Foitzik S. 2014. Age and ovarian development are related to worker personality and task allocation in the ant Leptothorax acervorum. Current Zoology: 60 392-400.
Binz, H., Foitzik, S. Staab, F., Menzel F. 2014. The chemistry of competition: exploitation of heterospecific cues depends on the dominance rank in the community. Animal Behaviour 94: 45-53.
Seifert, B., Kleeberg I., Feldmeyer, B., Pamminger, T., Jongepier, E. Foitzik, S. Temnothorax pilagens sp. n. – a new slave-making species of the tribe Formicoxenini from North America (Hymenoptera, Formicidae). Zookeys, 368: 65-77.
Pamminger, T., Foitzik, S., Kaufmann, K., Schützler, N. and Menzel, F. Worker personality and its association with spatially structured division of labor. Plos One 9, e79616.
Feldmeyer, B, Elsner D., Foitzik, S. 2014. Gene expression patterns associated with caste and reproductive status in ants: worker-specific genes are more derived than queen-specific ones. Molecular Ecology, 23: 151-161. Featured in News and Views Article by S. Sumner: The importance of genomic novelty in social evolution. Molecular Ecology, 23: 26-28:
Kramer, B., Scharf, I., Foitzik S. 2014. The role of per-capita productivity in the evolution of small colony sizes in ants. Behavioral Ecology and Sociobiology, 68: 41-53.
Kureck, I., Nicolai, B., Foitzik, S. 2013. Selection for early emergence, longevity and large body size in wingless, sib-mating ant males. Behavioral Ecology and Sociobiology 67: 1369-1377.
Pohl, S., Foitzik, S. Parasite scouting and host defence behaviours are influenced by colony size in the slave-making ant Protomognathus americanus. Insectes Sociaux, 60: 293-301.
Modlmeier, A.P., Foitzik S., Scharf, I. Starvation endurance of Temnothorax ants depends on group size, body size and access to larvae. Physiological Entomology, 38: 89-94.
Kureck, I., Nicolai, B., Foitzik, S. Similar performance of diploid and haploid males in an ant species without inbreeding avoidance. Ethology, 119: 360-637.
Pamminger, T., Leingärtner A., Achenbach A., Kleeberg I., Pennings P.S., Foitzik S. 2013. Geographic distribution of the anti-parasite trait “slave rebellion. Evolutionary Ecology, 27: 39-49.
Kureck, I. M., Jongepier E. Nicolai, B., Foitzik, S. 2012 No inbreeding depression but increased sexual investment in highly inbred ant colonies. Molecular Ecology 22:5613-5623.
Scharf, I, Modlmeier, A.P., Beros, S., Foitzik S. 2012 Ant societies buffer individual-level effects of parasite infections. American Naturalist, 180: 671-683.
Modlmeier, A.P., Pamminger, T, Foitzik S., Scharf, S. Cold resistance depends on acclimation and behavioral caste in a temperate ant. Naturwissenschaften, 10: 811-819.
Pamminger, T, Modlmeier, A.P., Suette S., Foitzik S. Raiders from the sky: slavemaker founding queens select for aggressive host colonies. Biology Letters, 8: 748-750.
Steinmeyer, C, Pennings, P.S., Foitzik, S. Multicolonial population structure and nestmate recognition in an extremely dense population of the European ant Lasius flavus. Insectes Sociaux, 59: 499-510.
Pamminger, T., Leingärtner A., Achenbach A., Kleeberg I., Pennings P.S., Foitzik S. Geographic distribution of the anti-parasite trait “slave rebellion. Evolutionary Ecology, online first: DOI 10.1007/s10682-012-9584-07.
Konrad, M., Pamminger, T, Foitzik S. 2012. Two pathways ensuring social harmony. Naturwissenschaften, 99:627–636.8.
Modlmeier, A.P., Liebmann, J.A., Foitzik S. 2012. Diverse societies are more productive: a lesson from ants. Proceedings of the Royal Society B 279: 2142-2150.9.
Scharf, I, Modlmeier, A., Fries, S, Tirard C, Foitzik S. 2012. Characterizing the collective personality of ant societies: Aggressive colonies do not abandon their home. Plos One 7: e33314. 10.
Scharf, I, Ovadia, O., Foitzik S. 2012. The advantage of alternative tactics of prey and predators depends on the spatial pattern of prey and social interactions among predators. Population Ecology 54: 187-196.
Foitzik, S., Rüger, M., Kureck, I. Metzler, D. Macro- and microgeographic genetic structure in an ant species with alternative reproductive tactics in sexuals. Journal of Evolutionary Biology 24: 2721-2730.
Pohl, S., Witte, V., Foitzik, S. 2011. Division of labor and slave raid initiation in slave-making ants. Behavioral Ecology and Sociobiology, 65: 2029-2036.
Modlmeier, A. P., Foitzik, S. 2011. Productivity increases with variation in aggression among group members in Temnothorax ants. Behavioral Ecology. 22: 1026-1032 .
Scharf, I., Pamminger, T., Foitzik, S. Differential response of ant colonies to intruders: attack strategies correlate with potential threat. Ethology, 117: 731-739.
Kureck, I. M., Neumann A. and S. Foitzik 2011. Wingless ant males adjust mate-guarding behaviour to the competitive situation in the nest. Animal Behaviour, 82: 339-346.
Scharf, I., Bauer, S., Fischer-Blass, B, Foitzik, S. Impact of a social parasite on ant host populations depends on host species, habitat and year. Biological Journal of the Linnean Society, 103: 559-570.
Pamminger, T., Scharf, I., Pennings, P., Foitzik, S. 2011. Increased host aggression as an induced defence against slavemaking ants. Behavioural Ecology, 22: 255-260.
Scharf, I., Fischer-Blass, B, Foitzik, S. Spatial structure and nest demography reveal the influence of competition, parasitism and habitat quality on slavemaking ants and their hosts. BMC Ecology 2011, 11:9.
Abbot, P., Abe, D., ... Foitzik, S., ... Zink, A. 2011. Inclusive fitness theory and eusociality. Nature 471: E1-E4.
Foitzik, S., Fröba, J. Rüger, M.H., Witte, V. 2011. Competition over workers: Fertility signalling in wingless queens of Hypoponera opacior. Insectes Sociaux, 58: 271-287.
Pennings, P., Achenbach, A., Foitzik, S. 2011. Similar evolutionary potentials in an obligate ant parasite and its two host species. Journal of Evolutionary Biology, 24: 871-886.
Pohl, S., Foitzik, S. 2011 Slave-making ants prefer larger, better defended host colonies. Animal Behaviour, 81: 61-68.
Foitzik, S, Kureck, I., Rüger, M., Metzler, D. 2010. Alternative reproductive tactics and the influence of local competition on sex allocation in the ant Hypoponera opacior. Behavioral Ecology and Sociobiology, 64:1641–1654.
Achenbach, A., Witte, V., Foitzik, S. 2010 Brood exchange experiments and chemical analyses shed light on slave rebellion in ants. Behavioral Ecology, 21: 948 - 956.
Bauer, S., Böhm, M., Witte V., Foitzik, S. 2010. An ant social parasite in-between two chemical disparate host species. Evolutionary Ecology, 24: 317–332.
Foitzik, S, Bauer, S, Laurent, S., Pennings, P.S. 2009. Genetic diversity, populations structure and sex-biased dispersal in three co-evolving species. Journal of Evolutionary Biology, 22: 2470-2480.
Bauer, S., Böhm, M., Witte V., Foitzik, S. 2009. Fight or flight? A geographic mosaic in host reaction and potency of a chemical weapon in the social parasite Harpagoxenus sublaevis. Behavioral Ecology and Sociobiology, 64:45–56.
Foitzik, S., Achenbach, A., Brandt, M. 2009. Locally-adapted social parasite affects density, social structure and life history of its ant hosts. Ecology 90: 1195–1206.
Achenbach, A., Foitzik, S. 2009. First evidence for slave rebellion: Enslaved ant workers systematically kill the brood of their social parasite Protomognathus americanus. Evolution 63: 1068–1075.
Witte, V., Foitzik S., Hashim, R., Maschwitz, U., Schulz S. 2009. Fine Tuning of Social Integration in two Myrmecophiles of the Ponerine Army Ant, Leptogenys distinguenda. Journal of Chemical Ecology 35:355–367.
Heinze, J., Foitzik, S. 2009. The evolution of queen numbers in ants: from one to many and back. In Organization of Insect Societies: Edited by Jürgen Gadau and Jennifer Fewell; Harvard University Press, Cambridge, MA, USA, 26-50.
Witte, V., Leingärtner A., Sabaß L., Hashim R., Foitzik S. 2008. Symbiont microcosm in an ant society and the diversity of interspecific interactions. Animal Behaviour, 76: 1477-1486.
Feldhaar, H., Foitzik, S., Heinze, J. 2008. Life-long commitment to the wrong partner: hybridization in ants. Philosophical Transactions of the Royal Society B, 363: 2891-2899.
Rueger, M. H., Fröba, J., Foitzik, S. 2008. Larval cannibalism and worker-induced separation of larvae in Hypoponera ants: a case of conflict over caste determination? Insectes Sociaux, 55: 12-21.
Foitzik, S., Sturm, H., Pusch, K., D’Ettorre, P., Heinze, J. 2007. Variation in nestmate recognition abilities, chemical cues and genetic diversity in Temnothorax ants. Animal Behaviour, 73, 999-1007.
Beibl. J., Buschinger, A., Foitzik, S., Heinze. J. 2007. Phylogeny and phylogeography of the Mediterranean species of the parasitic ant genus Chalepoxenus and its Temnothorax hosts. Insectes Sociaux, 54, 189 – 199.
Brandt, M., Fischer-Blass, B., Heinze, J., Foitzik, S.
2007. Population structure and coevolution in social parasites. Molecular Ecology, 16, 2063–2078.
Pusch, K., Heinze, J., Foitzik, S. 2006. The influence of hybridization on colony structure in the ant species pair Temnothorax nylanderi and T. crassispinus. Insectes Sociaux, 53: 439 – 445.
Brandt, M., Heinze, J., Foitzik, S. 2006. Dufour's gland secretion as a propaganda substance in the slavemaking ant Protomognathus americanus. Insectes Sociaux, 53: 291–299.
Pusch, K., Seifert, B., Foitzik, S., Heinze, J. 2006. Distribution and genetic divergence of two parapatric sibling ant species in Central Europe. Biological Journal of the Linnaean Society 8: 223–234.
Fischer-Blass, B., Heinze, J., Foitzik, S. 2006. Microsatellite analysis reveals strong, but differential impact of a social parasite on its two host species. Molecular Ecology, 15: 638-872.
Beibl J., Stuart, RJ, Heinze, J., Foitzik, S. 2005. Six origins of slavery in formicoxenine ants. Insectes Sociaux, 52: 291–297.
Brandt, M., Heinze, J., Schmitt, T., Foitzik, S. 2005. A chemical level in the coevolutionary arms race between an ant social parasite and its hosts. Journal of Evolutionary Biology, 18: 576–586.
Brandt, M., Foitzik, S., Fischer-Blass, B., Heinze, J. 2005. The coevolutionary dynamics of obligate ant social parasites: Between prudence and antagonism. Biological Reviews, 80: 1–17.
Rüger, MH, Heinze, J., Foitzik, S. 2005. Polymorphic microsatellite loci in the ponerine ant Hypoponera opacior (Hymenoptera, Formicidae). Molecular Ecology Notes 5: 236–238.
Brandt, M., Foitzik, S. 2004. Community context and specialization influence coevolution in a slavemaking ant and its hosts. Ecology, 85: 2997–3009.
Fischer, B. Foitzik, S. 2004 Local co-adaptation leading to a geographic mosaic of coevolution in a social parasite system. Journal of Evolutionary Biology, 17: 1026-1034.
Foitzik, S., Backus, V. L., Trindl, A., Herbers, J. M. 2004. Ecology of Leptothorax ants: impact of food, nest sites and social parasites. Behavioral Ecology and Sociobiology, 55: 484-455.
Foitzik, S., Strätz, M. Heinze, J. 2003. Ecology, life history, and resource allocation in the ant, Leptothorax nylanderi. Journal of Evolutionary Biology, 16: 670-680.
Foitzik, S., Fischer, B., Heinze, J. 2003. Arms-races between social parasites and their hosts: Geographic patterns of manipulation and resistance. Behavioral Ecology, 14: 80-88.
Heinze, J., Foitzik, S., Fischer, B., Wanke, T. Kipyatkov, V. E. 2003. The significance of latitudinal variation in body size in a holarctic ant, Leptothorax acervorum. Ecography, 26: 349-355.
Foitzik, S., Heinze, J., Oberstadt, B., Herbers, J. M. 2002. Mate guarding and alternative reproductive tactics in the ant Hypoponera opacior. Animal Behaviour 63: 597-604.
Herbers, J. M., Foitzik, S. 2002. Ecology of slavemaking ants and their hosts in north-temperate forests. Ecology 83(1): 148-163.
Strätz, M., Foitzik, S., Heinze, J. 2002. First description of Leptothorax crassispinus from Bavaria. Nachrichtenblatt bayerischer Entomologen, 51: 26-29.
Foitzik, S., DeHeer, C. J., Hunjan, D. N., Herbers, J. M. 2001. Coevolution in host-parasite systems: Behavioral strategies of slavemaking ants and their hosts. Proceedings of the Royal Society B, London 268: 1139 – 1146.
Foitzik, S., Herbers, J. M. 2001. Colony structure of a slavemaking ant: I. Intra-colony relatedness, worker reproduction and polydomy. Evolution 55: 307-315.
Foitzik, S., Herbers, J. M. 2001. Colony structure of a slavemaking ant: II. Frequency of slave raids and impact on the host population. Evolution 55: 316-323.
Foitzik, S., Heinze, J. 2001. Microgeographic genetic structure and intraspecific parasitism in the ant Leptothorax nylanderi. Ecological Entomology 26: 449-456.
Herbers, J. M., DeHeer, C. J., Foitzik, S. 2001 Conflict over sex allocation drives conflict over reproductive allocation in perennial social insect colonies. American Naturalist 158: 178-192.
Foitzik, S., Heinze, J. 2000. Intraspecific parasitism and split sex ratios in a monogynous and monandrous ant. Behavioural Ecology and Sociobiology 47: 424-431.
Foitzik, S., Heinze, J. 1999. Non-random size differences between sympatric Leptothorax ants. Entomologia Generalis 24: 65-74.
Heinze, J., Foitzik, S., Oberstadt, B., Rüppell, O., Hölldobler, B. 1999. A female caste specialized for the production of unfertilized eggs in the ant Crematogaster smithi. Naturwissenschaften 86: 93-95.
Foitzik, S., Heinze, J. 1998. Nest site limitation and colony take-over in the ant Leptothorax nylanderi. Behavioral Ecology 9: 367-375.
Heinze, J., Rüppell, O., Foitzik, S., Buschinger, A. 1998. First records of ants (Hymenoptera: Formicidae) with cysticercoids of tapeworms (Cestoda: Dilepididae) from the Southwestern United States. Florida Entomologist 81: 122-125.
Heinze, J., Foitzik, S., Kipyatkov, V.E., Lopatina, E.B. 1998. Latitudinal variation in cold hardiness and body size in the boreal ant Leptothorax acervorum. Entomologia Generalis, 22: 305-312.
Foitzik, S., Haberl, M., Gadau, J., Heinze, J. 1997. Mating frequency of Leptothorax nylanderi ant queens determined by microsatellite analysis. Insectes Sociaux 44: 219-227.
Heinze, J., Foitzik, S., Hippert, A., Hölldobler, B. 1996. Apparent dear-enemy phenomenon and environmental-based recognition cues in the ant Leptothorax nylanderi. Ethology 102: 510-522.