Scharf, Inon Dr.
Dr. Inon Scharf
Post Doc, Scientific Assistant
Place & date of birth: Ashdod, Israel, 20 June 1980.
2001-2004: Department of Life Sciences, The Hebrew University of Jerusalem, Israel, B.Sc. (with distinction).
2004-2006: Department of Life Sciences, Ben-Gurion University of the Negev, Israel, M.Sc. (with distinction).
2004-2009: Department of Life sciences, Ben-Gurion University of the Negev, Israel, Ph.D. (direct program, with distinction). Supervisors: Dr. Ofer Ovadia, Prof. Zvika Abramsky.
2001-2004: "Amirim" fellowship for excellent students in the Faculty of Natural Sciences, The Hebrew University.
2006: A scholarship from the Department of Life Sciences, Ben-Gurion University, for excellence in teaching and studying. 2008: Kreitman prize for an excellent PhD student.
2008: Merav Ziv prize for an excellent PhD student in Ecology & Evolution.
2008: Aharon Katzir student travel fellowship.
2009-2010: Rothschild fellowship for a post-doc researcher.
2010-2012: Minerva fellowship (of the Max Planck society) for a post-doc researcher.
June 2006: "Evolution 2006" at SUNY, Stony Brook, NY, USA (talk).
October 2007: Entomological society of Israel – annual meeting, The Hebrew University of Jerusalem, Rehovot, Israel (talk).
April 2008: Department of zoology, Stockholm University, Stockholm, Sweden (talk).
June 2008: Ecological society of Israel – annual meeting, Technion - Israel Institute of Technology, Haifa, Israel (poster).
September 2008: German society of zoology – annual meeting, University of Jena, Jena, Germany (talk).
October 2008: Institute of Zoology, University of Zurich, Zurich, Switzerland (talk).
May 2009: Department of life sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel (PhD concluding seminar).
August 2009: European society of evolutionary biology – 12th congress, Politecnico di Torino, Turin, Italy (poster).
November 2009: Institute of Evolution & Ecology, Eberhard Karl University of Tübingen, Tübingen, Germany (talk).
December 2009: Department of Entomology, Faculty of Agriculture, The Hebrew University of Jerusalem, Rehovot, Israel (talk).
December 2009: Department of Evolutionary & Environmental Biology, University of Haifa, Haifa, Israel (talk).
February 2010: Division of Behavioral Ecology, University of Bern, Bern, Switzerland (talk).
February 2010: "Biology10" – Joint meeting of the Swiss zoological, botanical and systematic societies, University of Neuchâtel, Neuchâtel, Switzerland (poster).
May 2010: Evolutionary Ecology Field Station, Julius Maximilian University of Würzburg, Germany (talk).
July 2010: Division of Ecology, Pierre and Marie Curie University, Paris, France (talk).
September 2010: German society of zoology – annual meeting, University of Hamburg, Germany (talk).
December 2010: Department of Zoology, Tel Aviv University, Israel (talk).
April 2011: Division of Experimental Ecology, The ETH, Zurich, Switzerland (talk).
June 2011: Faculty of Biology, Technion - Israel Institute of Technology, Haifa, Israel (talk).
August 2011: European society of evolutionary biology – 13th congress, University of Tübingen, Tübingen, Germany (poster).
September –October 2008: Project under the supervision of Prof. Wolf Blanckenhorn, University of Zurich, Switzerland.
From October 2009: Post-doc researcher in the Institute of Ecology, Ludwig Maxmilian University of Munich, and in the Institute of Zoology, Johannes Gutenberg University of Mainz. Host: Prof. Susanne Foitzik.
Boaz Golan and Daphna Ben-Yehoshua (2007-2008): Supervision of a 3rd year BSc project.
2004-2005: Teaching assistant in Biometry (for MSc and last year BSc students).
2004-2009: Teaching assistant in Population Ecology (for MSc and last year of BSc students).
2004-2009: Teaching assistant in Faunistics (for BSc students).
I am an evolutionary ecologist of insects, interested mainly in insect behavior and life history. I am a post-doctoral researcher in the Evolutionary Biology lab, supported currently by the Minerva Foundation of the Max Planck Society. I completed my PhD in 2009 at Ben-Gurion University, Israel, working on the foraging behavior and life history of pit-building antlions. I started my post-doc in the lab of Prof. Susanne Foitzik, still in the Ludwig Maximilian University of Munich, in October 2009, focusing on behavioral and life-history effects of slavemaking ants on their host colonies. I moved to the University of Mainz in November 2010, following the relocation of the whole group. Starting from October 2012 I will be a member of the Department of Zoology, Tel Aviv University, Israel http://www.tau.ac.il/lifesci/departments/zoology/
My PhD research in the lab of Dr. Ofer Ovadia http://www.bgu.ac.il/~oferovad/ dealt with the sit-and-wait predator, the pit-building antlion. My work was composed of three complementary parts: (1) the foraging behavior of this interesting predator which ambushes its prey while buried in sand; (2) the evolution of life-history traits of pit-building antlions; (3) simulation models of searching strategies, especially comparing between the sit-and-wait and the widely foraging mode (i.e., active search of prey), which is more common in nature.
Foraging behavior has been developed for widely foraging animals (i.e., animals that actively search for their prey) and it was enriching to draw analogies between the classical theory and its possible applications to sit-and-wait predators, which also construct traps (e.g., spiders and antlions). Their behavior was often considered as automatic or stereotypic, but I showed that antlions greatly respond to their environment by modifying their trap and its construction. For example, antlions evolved to respond to intrinsic and extrinsic factors while constructing and maintaining their pits, such as hunger level and predation risk. In addition, my research has shown that antlions exhibit high levels of phenotypic plasticity, and are sensitive to growth conditions, such as temperature, humidity and food availability. More specifically, life-history traits have both genetic and plastic components, and a significant interaction term. Antlions from the Mediterranean region of Israel are larger and develop more slowly compared to antlions from the desert region. The former showed higher plasticity levels than the latter. Regarding the efficiency evaluation of the sit-and-wait foraging mode, I programmed several simulation models, in this context. I showed that the sit-and-wait foraging mode is not as inferior as previously thought, and it can do quite well, especially when the prey and predator use directional movement. Therefore, it suggests specific conditions under which the sit-and-wait foraging mode can more easily evolve.
Behavior of pit-building antlions: Scharf I, Lubin Y, Ovadia O (2011) Foraging decisions and behavioural flexibility in trap-building predators: a review. Biological Reviews (DOI: 10.1111/j.1469-185X.2010.00163.x)
Life-history of pit-building antlions: Scharf I, Filin I, Golan M, Buchshtav M, Subach A, Ovadia O (2008) A comparison between desert and Mediterranean antlion populations: Differences in life history and morphology. Journal of Evolutionary Biology 21:162-172
Modeling of foraging modes: Scharf I, Nulman E, Ovadia O, Bouskila A (2006) Efficiency evaluation of two competing foraging modes under different conditions. American Naturalist 168:350-357
I started my post-doc training in October 2009, combining two related subjects: The behavioral and life-history responses of potential host colonies to the presence or attack by slavemaking ants. Slavemaking ants are social parasites which invade host colonies and steal worker pupae. The later-emerged enslaved workers perform all tasks in the slavemaking ants’ colony, while the slavemaking workers specialize in robbing host colonies for more brood.
In my first project together with Tobias Pamminger, we tested the aggressive response of the ant Temnothorax longispinosus, which serves as a potential host, to the slavemaking ant Protomognathus americanus. An encounter with a slavemaking ant increases the aggression of the potential host colony towards both the slavemaker and a conspecific worker from a different nest. These findings indicate that the host colony “remembers” such an encounter and point to an induced behavioral defense. Induced behavioral defenses commonly evolved when the maintenance of a high alert status is costly and when such defense can be initiated following a specific trigger. As a part of this research, I present a detailed ethological analysis of the aggressive response of T. longispinosus when facing four different species, posing different levels of threat to their colonies. I also study different species and systems of host ants and their potential slavemakers, evaluating the dominant interactions in each system. For example, competition is the dominant factor shaping host colonies' life history in a poor habitat, while the pressure of slavemaking ants is more important in richer habitats. I recently finalized a comprehensive synthesis, which focuses on various life-history traits that correlate with colony size in cavity-dwelling ants. Analyzing a large dataset of eight species of ten populations enabled documenting general patterns, but also revealed system-specific ones. Interestingly, there is much evidence that colony size of these ants is limited by low survival rate and decrease of colony efficiency with colony size. I am currently working on characterizing and understanding which factors the aggressive response of a related species, Temnothorax nylanderi, depends on. My future plans include studying life history trade-offs and their association with behavior and physiology (e.g., estimation of the status of the immune system of insects, oxidative stress, etc.).
Aggressive behavior of host ants: Pamminger T, Scharf I, Pennings P, Foitzik S. 2011. Slave-making ants induce social immunity in host colonies. Behavioral Ecology (doi 10.1093/beheco/arq191)
Life history of host ants: Scharf I, Fischer-Blass B, Foitzik S. Spatial structure demonstrates varying impact of habitat quality, competition and parasitism in two systems of slavemaking ants and their hosts. BMC Ecology 11:9
Project on the life history of the yellow dung fly
In 2008 I spent two months in the laboratory of Prof. Wolf Blanckenhorn at the University of Zurich http://www.ieu.uzh.ch/staff/professors/blanckenhorn.html I conducted a large-scale experiment testing for maternal, temperature and photoperiod effects on diapauses tendency, development, body size and egg chemical content of the yellow dung fly. An interesting result is the effect of environmental conditions experienced throughout the maternal stage on the development of the offspring.
Scharf I, Bauerfeind SS, Blanckenhorn WU, Schäfer MA (2010) Effects of maternal and offspring environmental conditions on growth, development and diapause in latitudinal yellow dung fly populations. Climate Research 43:115-125
Scharf I, Ovadia O (2006) Factors influencing site abandonment and site selection in a sit-and-wait predator: A review of pit-building antlion larvae. Journal of Insect Behavior 19:197-218.
Scharf I, Nulman E, Ovadia O, Bouskila A (2006) Efficiency evaluation of two competing foraging modes under different conditions. American Naturalist 168:350-357.
Scharf I, Filin I, Golan M, Buchshtav M, Subach A, Ovadia O (2008) A comparison between desert and Mediterranean antlion populations: Differences in life history and morphology. Journal of Evolutionary Biology 21:162-172.
Scharf I, Hollender Y, Subach A, Ovadia O (2008) Effect of spatial pattern and microhabitat on pit construction and relocation in Myrmeleon hyalinus (Neuropetera: Myrmeleontidae) larvae. Ecological Entomology 33:337-345.
Loria R, Scharf I*, Subach A, Ovadia O (2008) The interplay between foraging mode, habitat structure and predator presence in antlions. Behavioral Ecology & Sociobiology 62:1185-1192.
Scharf I, Filin I, Ovadia O (2008) An experimental design and a statistical analysis separating interference from exploitation competition. Population Ecology 50:319-324.
Scharf I, Ovadia O, Bouskila A (2008) Prey encounter rate by predators: Discussing the realism of grid-based models and how to model the predator's foraging mode: A reply to Avgar et al. American Naturalist 172:596-598.
Scharf I, Subach A, Ovadia O (2008) Foraging behaviour and habitat selection in pit-building antlion larvae in constant light or dark conditions. Animal Behaviour 76:2049-2057.
Scharf I, Golan B, Ovadia O (2009) The effect of sand depth, feeding regime, density and body mass on the foraging behavior of a pit-building antlion. Ecological Entomology 34:26-33.
Scharf I, Kotler B, Ovadia O (2009) Consequences of food distribution for optimal searching behavior: an evolutionary model. Evolutionary Ecology 23:245-259.
Scharf I, Filin I, Ben-Yehoshua D, Ovadia O (2009) Phenotypic plasticity and variation in morphological and life history traits of antlion adults. Zoology 112:139-150.
Scharf I, Filin I, Ovadia O (2009) A trade-off between growth and starvation endurance in a pit-building antlion. Oecologia 160:453-460.
Subach A, Scharf I, Ovadia O (2009) Foraging behavior and predation success of the sand viper (Cerastes vipera). Canadian Journal of Zoology 87:520-528.
Scharf I, Filin I, Subach A, Ovadia O (2009) A comparison between two desert populations of a sit-and-pursue antlion: differences in morphology and life-history. Naturwissenschaften 96:1147-1156.
Scharf I, Barkae ED, Ovadia O (2010) Response of pit-building antlions to repeated unsuccessful encounters with prey. Animal Behaviour 79:153-158.
Scharf I, Bauerfeind SS, Blanckenhorn WU, Schäfer MA (2010) Effects of maternal and offspring environmental conditions on growth, development and diapause in latitudinal yellow dung fly populations. Climate Research 43:115-125.
Barkae ED, Scharf I, Subach A, Ovadia O (2010) Short term behavioral and developmental responses of pit-building antlion larvae to sand disturbance, competition and intra-guild-predation. Zoology 113:308-315.
Scharf I, Lubin Y, Ovadia O (2011) Modifications in trap characteristics as representing foraging behavior in trap-building predators: a review. Biological Reviews 86:626-639.
Pamminger T, Scharf I*, Pennings P, Foitzik S (2011) Increased host aggression as an induced defense against slave-making ants. Behavioral Ecology 22:255-260.
Scharf I, Pamminger T, Foitzik S. (2011) Differential response of ant colonies to intruders: attack strategies correlate with potential threat. Ethology 117:731-739. Covered by BBC Nature: http://www.bbc.co.uk/nature/13982886
Scharf I, Fischer-Blass B, Foitzik S (2011) Spatial structure and nest demography demonstrates varying impact of habitat quality, competition and parasitism in two systems of slavemaking ants and their hosts. BMC Ecology 11:9.
Scharf I, Bauer S, Fischer-Blass B, Foitzik S (2011) 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.
Scharf I, Ovadia O, Foitzik S (2011) The advantage of alternative tactics of prey and predators depends on the spatial pattern of prey and social interactions among predators. Population Ecology (in press).
Scharf, I, Modlmeier, A., Fries, S, Tirard C, Foitzik S. Characterizing the collective personality of ant societies: Aggressive colonies do not abandon their home. Plos One (in press).
Scharf, I, Modlmeier, A.P., Beros, S., Foitzik S. Ant societies buffer individual-level effects of parasite infections. American Naturalist (in press).
* I equally contributed to the paper.
Manuscripts in Review & Preparation
Filin I, Scharf I, Ovadia O. Individual variation and plasticity in life history of antlion larvae, in reaction to prey availably, population density, and climatic conditions. Journal of Animal Ecology (In review, major revision requested).
Scharf I, Kramer B, Foitzik S. The evolution of colony size in cavity-dwelling ants: the interplay between colony size and various life-history traits. Evolutionary Ecology (In review).
Barkae ED, Scharf I, Abramsky Z, Ovadia O. A generalist pit-building antlion is more efficient than a specialist even in the specialist’s preferred environment. In preparation.