@misc{9860, author = {Greenwood, Jenny and Milutinovic, Barbara and Peuß, Robert and Behrens, Sarah and Essar, Daniela and Rosenstiel, Philip and Schulenburg, Hinrich and Kurtz, Joachim}, publisher = {Springer Nature}, title = {{Additional file 5: Table S3. of Oral immune priming with Bacillus thuringiensis induces a shift in the gene expression of Tribolium castaneum larvae}}, doi = {10.6084/m9.figshare.c.3756974_d5.v1}, year = {2017}, } @article{914, abstract = {Infections with potentially lethal pathogens may negatively affect an individual’s lifespan and decrease its reproductive value. The terminal investment hypothesis predicts that individuals faced with a reduced survival should invest more into reproduction instead of maintenance and growth. Several studies suggest that individuals are indeed able to estimate their body condition and to increase their reproductive effort with approaching death, while other studies gave ambiguous results. We investigate whether queens of a perennial social insect (ant) are able to boost their reproduction following infection with an obligate killing pathogen. Social insect queens are special with regard to reproduction and aging, as they outlive conspecific non-reproductive workers. Moreover, in the ant Cardiocondyla obscurior, fecundity increases with queen age. However, it remained unclear whether this reflects negative reproductive senescence or terminal investment in response to approaching death. Here, we test whether queens of C. obscurior react to infection with the entomopathogenic fungus Metarhizium brunneum by an increased egg-laying rate. We show that a fungal infection triggers a reinforced investment in reproduction in queens. This adjustment of the reproductive rate by ant queens is consistent with predictions of the terminal investment hypothesis and is reported for the first time in a social insect.}, author = {Giehr, Julia and Grasse, Anna V and Cremer, Sylvia and Heinze, Jürgen and Schrempf, Alexandra}, issn = {20545703}, journal = {Royal Society Open Science}, number = {7}, publisher = {Royal Society, The}, title = {{Ant queens increase their reproductive efforts after pathogen infection}}, doi = {10.1098/rsos.170547}, volume = {4}, year = {2017}, } @misc{9853, abstract = {Egg laying rates and infection loads of C. obscurior queens}, author = {Giehr, Julia and Grasse, Anna V and Cremer, Sylvia and Heinze, Jürgen and Schrempf, Alexandra}, publisher = {The Royal Society}, title = {{Raw data from ant queens increase their reproductive efforts after pathogen infection}}, doi = {10.6084/m9.figshare.5117788.v1}, year = {2017}, } @article{734, abstract = {Social insect societies are long-standing models for understanding social behaviour and evolution. Unlike other advanced biological societies (such as the multicellular body), the component parts of social insect societies can be easily deconstructed and manipulated. Recent methodological and theoretical innovations have exploited this trait to address an expanded range of biological questions. We illustrate the broadening range of biological insight coming from social insect biology with four examples. These new frontiers promote open-minded, interdisciplinary exploration of one of the richest and most complex of biological phenomena: sociality.}, author = {Kennedy, Patrick and Baron, Gemma and Qiu, Bitao and Freitak, Dalial and Helantera, Heikki and Hunt, Edmund and Manfredini, Fabio and O'Shea Wheller, Thomas and Patalano, Solenn and Pull, Christopher and Sasaki, Takao and Taylor, Daisy and Wyatt, Christopher and Sumner, Seirian}, issn = {01695347}, journal = {Trends in Ecology and Evolution}, number = {11}, pages = {861 -- 872}, publisher = {Cell Press}, title = {{Deconstructing superorganisms and societies to address big questions in biology}}, doi = {10.1016/j.tree.2017.08.004}, volume = {32}, year = {2017}, } @phdthesis{819, abstract = {Contagious diseases must transmit from infectious to susceptible hosts in order to reproduce. Whilst vectored pathogens can rely on intermediaries to find new hosts for them, many infectious pathogens require close contact or direct interaction between hosts for transmission. Hence, this means that conspecifics are often the main source of infection for most animals and so, in theory, animals should avoid conspecifics to reduce their risk of infection. Of course, in reality animals must interact with one another, as a bare minimum, to mate. However, being social provides many additional benefits and group living has become a taxonomically diverse and widespread trait. How then do social animals overcome the issue of increased disease? Over the last few decades, the social insects (ants, termites and some bees and wasps) have become a model system for studying disease in social animals. On paper, a social insect colony should be particularly susceptible to disease, given that they often contain thousands of potential hosts that are closely related and frequently interact, as well as exhibiting stable environmental conditions that encourage microbial growth. Yet, disease outbreaks appear to be rare and attempts to eradicate pest species using pathogens have failed time and again. Evolutionary biologists investigating this observation have discovered that the reduced disease susceptibility in social insects is, in part, due to collectively performed disease defences of the workers. These defences act like a “social immune system” for the colony, resulting in a per capita decrease in disease, termed social immunity. Our understanding of social immunity, and its importance in relation to the immunological defences of each insect, continues to grow, but there remain many open questions. In this thesis I have studied disease defence in garden ants. In the first data chapter, I use the invasive garden ant, Lasius neglectus, to investigate how colonies mitigate lethal infections and prevent them from spreading systemically. I find that ants have evolved ‘destructive disinfection’ – a behaviour that uses endogenously produced acidic poison to kill diseased brood and to prevent the pathogen from replicating. In the second experimental chapter, I continue to study the use of poison in invasive garden ant colonies, finding that it is sprayed prophylactically within the nest. However, this spraying has negative effects on developing pupae when they have had their cocoons artificially removed. Hence, I suggest that acidic nest sanitation may be maintaining larval cocoon spinning in this species. In the next experimental chapter, I investigated how colony founding black garden ant queens (Lasius niger) prevent disease when a co-foundress dies. I show that ant queens prophylactically perform undertaking behaviours, similar to those performed by the workers in mature nests. When a co-foundress was infected, these undertaking behaviours improved the survival of the healthy queen. In the final data chapter, I explored how immunocompetence (measured as antifungal activity) changes as incipient black garden ant colonies grow and mature, from the solitary queen phase to colonies with several hundred workers. Queen and worker antifungal activity varied throughout this time period, but despite social immunity, did not decrease as colonies matured. In addition to the above data chapters, this thesis includes two co-authored reviews. In the first, we examine the state of the art in the field of social immunity and how it might develop in the future. In the second, we identify several challenges and open questions in the study of disease defence in animals. We highlight how social insects offer a unique model to tackle some of these problems, as disease defence can be studied from the cell to the society. }, author = {Pull, Christopher}, issn = {2663-337X}, pages = {122}, publisher = {Institute of Science and Technology Austria}, title = {{Disease defence in garden ants}}, doi = {10.15479/AT:ISTA:th_861}, year = {2017}, } @article{732, abstract = {Background: Social insects form densely crowded societies in environments with high pathogen loads, but have evolved collective defences that mitigate the impact of disease. However, colony-founding queens lack this protection and suffer high rates of mortality. The impact of pathogens may be exacerbated in species where queens found colonies together, as healthy individuals may contract pathogens from infectious co-founders. Therefore, we tested whether ant queens avoid founding colonies with pathogen-exposed conspecifics and how they might limit disease transmission from infectious individuals. Results: Using Lasius Niger queens and a naturally infecting fungal pathogen Metarhizium brunneum, we observed that queens were equally likely to found colonies with another pathogen-exposed or sham-treated queen. However, when one queen died, the surviving individual performed biting, burial and removal of the corpse. These undertaking behaviours were performed prophylactically, i.e. targeted equally towards non-infected and infected corpses, as well as carried out before infected corpses became infectious. Biting and burial reduced the risk of the queens contracting and dying from disease from an infectious corpse of a dead co-foundress. Conclusions: We show that co-founding ant queens express undertaking behaviours that, in mature colonies, are performed exclusively by workers. Such infection avoidance behaviours act before the queens can contract the disease and will therefore improve the overall chance of colony founding success in ant queens.}, author = {Pull, Christopher and Cremer, Sylvia}, issn = {14712148}, journal = {BMC Evolutionary Biology}, number = {1}, publisher = {BioMed Central}, title = {{Co-founding ant queens prevent disease by performing prophylactic undertaking behaviour}}, doi = {10.1186/s12862-017-1062-4}, volume = {17}, year = {2017}, } @article{459, abstract = {The social insects bees, wasps, ants, and termites are species-rich, occur in many habitats, and often constitute a large part of the biomass. Many are also invasive, including species of termites, the red imported fire ant, and the Argentine ant. While invasive social insects have been a problem in Southern Europe for some time, Central Europa was free of invasive ant species until recently because most ants are adapted to warmer climates. Only in the 1990s, did Lasius neglectus, a close relative of the common black garden ant, arrive in Germany. First described in 1990 based on individuals collected in Budapest, the species has since been detected for example in France, Germany, Spain, England, and Kyrgyzstan. The species is spread with soil during construction work or plantings, and L. neglectus therefore is often found in parks and botanical gardens. Another invasive ant now spreading in southern Germany is Formica fuscocinerea, which occurs along rivers, including in the sandy floodplains of the river Isar. As is typical of pioneer species, F. fuscocinerea quickly becomes extremely abundant and therefore causes problems for example on playgrounds in Munich. All invasive ant species are characterized by cooperation across nests, leading to strongly interconnected, very large super-colonies. The resulting dominance results in the extinction of native ant species as well as other arthropod species and thus in the reduction of biodiversity.}, author = {Cremer, Sylvia}, issn = {2366-2875}, journal = {Rundgespräche Forum Ökologie}, pages = {105 -- 116}, publisher = {Verlag Dr. Friedrich Pfeil}, title = {{Invasive Ameisen in Europa: Wie sie sich ausbreiten und die heimische Fauna verändern}}, volume = {46}, year = {2017}, } @article{558, abstract = {Immune specificity is the degree to which a host’s immune system discriminates among various pathogens or antigenic variants. Vertebrate immune memory is highly specific due to antibody responses. On the other hand, some invertebrates show immune priming, i.e. improved survival after secondary exposure to a previously encountered pathogen. Until now, specificity of priming has only been demonstrated via the septic infection route or when live pathogens were used for priming. Therefore, we tested for specificity in the oral priming route in the red flour beetle, Tribolium castaneum. For priming, we used pathogen-free supernatants derived from three different strains of the entomopathogen, Bacillus thuringiensis, which express different Cry toxin variants known for their toxicity against this beetle. Subsequent exposure to the infective spores showed that oral priming was specific for two naturally occurring strains, while a third engineered strain did not induce any priming effect. Our data demonstrate that oral immune priming with a non-infectious bacterial agent can be specific, but the priming effect is not universal across all bacterial strains.}, author = {Futo, Momir and Sell, Marie and Kutzer, Megan and Kurtz, Joachim}, issn = {1744-9561}, journal = {Biology Letters}, number = {12}, publisher = {The Royal Society}, title = {{Specificity of oral immune priming in the red flour beetle Tribolium castaneum}}, doi = {10.1098/rsbl.2017.0632}, volume = {13}, year = {2017}, } @article{1184, abstract = {Across multicellular organisms, the costs of reproduction and self-maintenance result in a life history trade-off between fecundity and longevity. Queens of perennial social Hymenoptera are both highly fertile and long-lived, and thus, this fundamental trade-off is lacking. Whether social insect males similarly evade the fecundity/longevity trade-off remains largely unstudied. Wingless males of the ant genus Cardiocondyla stay in their natal colonies throughout their relatively long lives and mate with multiple female sexuals. Here, we show that Cardiocondyla obscurior males that were allowed to mate with large numbers of female sexuals had a shortened life span compared to males that mated at a low frequency or virgin males. Although frequent mating negatively affects longevity, males clearly benefit from a “live fast, die young strategy” by inseminating as many female sexuals as possible at a cost to their own survival.}, author = {Metzler, Sina and Heinze, Jürgen and Schrempf, Alexandra}, journal = {Ecology and Evolution}, number = {24}, pages = {8903 -- 8906}, publisher = {Wiley-Blackwell}, title = {{Mating and longevity in ant males}}, doi = {10.1002/ece3.2474}, volume = {6}, year = {2016}, } @article{1202, author = {Milutinovic, Barbara and Peuß, Robert and Ferro, Kevin and Kurtz, Joachim}, journal = {Zoology }, number = {4}, pages = {254 -- 261}, publisher = {Elsevier}, title = {{Immune priming in arthropods: an update focusing on the red flour beetle}}, doi = {10.1016/j.zool.2016.03.006}, volume = {119}, year = {2016}, }