Dr. Tamar Keasar
Senior Lecturer

Contact:

Department of Biology, University of Haifa at Oranim, Tivon 36006, Israel
Tel: (972) 4 9838705
Fax: (972) 4 9539608
E-mail: tkeasar (at) research.haifa.ac.il

Education:

B.Sc. 1985-1988 Hebrew University, Jerusalem, Israel  Biology
M.Sc. 1989-1991 Hebrew University, Jerusalem, Israel Ecology
Ph.D. 1992-1997 Hebrew University, Jerusalem, Israel Behavioral Ecology
Post-Doc 1997-1998 University of California, Santa Cruz Behavioral Ecology


Research interests:

I am interested in insect behavioral ecology within the framework of pollination and host-parasitoid interactions. My research on pollination ecology concerns pollinator learning and decision-making; social organization of pollinators; and agricultural pollination. Recent and ongoing projects include: 

My recent work on parasitoid ecology deals with the ecology of polyembryonic parasitoid development; the role of learning in parasitoid behavior; and the use of parasitoids for biological control. Projects include:

Teaching:

Publications:

A. Ph.D. Dissertation:

Sampling effort in foraging bumblebees; Thesis in English; Submitted to the Hebrew University of Jerusalem in 1997, Degree awarded in 1998; Supervisors: A Shmida, U Motro.

B. Edited Books and Special Journal Issues Published:

Guest editor for the Israel Journal of Plant Sciences (2009), special issue on "Developments in plant-pollinator interactions". Vol 57, no. 3, 275 pages.

C. Articles In Refereed Journals:

PUBLISHED:

  1. Safriel UN, Erez N, Keasar T, 1993. Long-term effects of transplanted limpets on an experimental marine biofouling community. Biofouling 6:261-278.
  2. Safriel UN, Cohen Y, Erez N, Gateno D, Keasar T, Dolev Y, 1993. Biological control of marine biofouling. Oebalia 19S:193-199.
  3. Keasar T, Safriel UN, 1994. The moulding of a territory - effects of food and competitors on movement patterns in Patella caerulea. Ethology, Ecology and Evolution 6:103-115. Ref
  4. Safriel UN, Erez N, Keasar T, 1994. How do limpets maintain barnacle-free submerged artificial surfaces? Bulletin of Marine Science 54:17-23. Ref
  5. Shkedy Y, Safriel UN, Keasar T, 1995. Life-history of Balanus amphitrite and Chthamalus stellatus in an intertidal fouling community in Israel. Israel Journal of Zoology 41:147-161.
  6. Keasar T, Motro U, Shur Y, Shmida A, 1996. Overnight memory retention of foraging bumblebees in imperfect. Animal Behavior 52:95-104. Ref
  7. Keasar T, Shmida A, Motro U, 1996. Innate movement rules in foraging bees: flight distances are affected by recent rewards and are correlated with choice of flower type. Behavioral Ecology and Sociobiology 39:381-388. Ref
  8. Keasar T, Bilu Y, Motro U,  Shmida A, 1997. Foraging choices of bumblebees on equally-rewarding artificial flowers of different colors. Israel Journal of Plant Sciences 45:219-229. Ref
  9. Keasar T, 2000.  The spatial distribution of non-rewarding artificial flowers affects pollinator attraction. Animal Behaviour 60:639-646. Ref
  10. Keasar T, Ney-Nifle M, Mangel M, 2000. Evidence for learning of visual host-associated cues in the parasitoid wasp Trichogramma thalense. Israel Journal of Zoology 46:24-247. Ref
  11. Keasar T, Ney-Nifle M, Mangel M, Swezey S, 2001. Early oviposition experience affects patch residence time in a foraging parasitoid. Entomologia Experimentalis et Applicata, 98:123-132. Ref
  12. Ney-Nifle M, Keasar T, Shmida A, 2001. Color and location learning in bumblebees in a two-phase conditioning experiment. Journal of Insect Behavior 14:697-711. Ref
  13. Keasar, T, 2001. Conservation of native pollinators via honeybee conservation.
    Conservation Ecology 5(2): r5. [online] URL: http://www.consecol.org/vol5/iss2/resp5
  14. Blarer A, Keasar T, Shmida A., 2002 Possible mechanisms for the formation of flower size preferences by foraging bumblebees. Ethology 108:341-351. Ref
  15. Keasar T, Rashkovich E, Cohen D, Shmida A., 2002. Choice behavior of bees in two-armed bandit situations: experiments and possible decision rules. Behavioral Ecology 13:757-765. Ref
  16. Bar Shai, N, Samuels R, Keasar T, Motro U, Shmida A., 2004. Flight durations in bumblebees under manipulation of feeding choices.  Journal of Insect Behavior, 17:155-168. Ref
  17. Gottlieb D, Keasar T, Shmida A, Motro U, 2005. Possible foraging benefits of bimodal daily activity in Proxylocopa olivieri (Lepeletier) (Hymenoptera: Anthophoridae). Environmental Entomology 34:417-424. Ref
  18. Keasar T, Kalish A, Becher O, Steinberg S, 2005. Spatial and temporal dynamics of potato tuber moth infestation in field-stored potatoes. Journal of Economic Entomology 98:222-228.
  19. Keasar T, Baruch R, Grobgeld E., 2005. Web-enhanced instruction in college-level biology courses: student attitudes, usage patterns and achievements. Australasian Journal of Distance Education, 21:533-545.
  20. Keasar T, Segoli M, Barak R, Steinberg  S, Giron D, Strand MR, Bouskila A,  Harari AR, 2006. Costs and consequences of superparasitism in the polyembryonic parasitoid Copidosoma koehleri. Ecological Entomology 31:277-283. Ref
  21. Keasar T, Sheffer N, Glusman G, Libersat F, 2006. Host handling: an innate component of foraging behavior in theparasitoidwasp Ampulex compressa. Ethology 112:699-706.
  22. Arnon R, Keasar T, Pollak G, Cohen D, Shmida A, 2006. Honesty of signaling and pollinator attraction: the case of flag-like bracts. Israel Journal of Plant Sciences 54:119-128. Ref
  23. Keasar T, Goubitz S, Shmida A, 2007. Age-related sampling of food sources by unsuccessful foraging bumblebees (Hymenoptera: Apidae: Bombus). Entomologia Generalis 29: 201-211. Ref
  24. Keasar T, Fershtman I, Forotan R, Shmida A, 2007. Learning performance of foraging bumblebees (Hymenoptera: Apidae: Bombus) under manipulation of inter-visit time intervals. Entomologia Generalis, 29: 213-224. Ref
  25. Keasar T, Sadeh A, Shilo M, Ziv Y, 2007. Social Organization and Pollination Efficiency in the Carpenter Bee Xylocopa pubescens (L.) (Hymenoptera: Apidae: Anthophoridae). Entomologia Generalis 29:225-236. Ref
  26. Keasar T, Sadeh A., 2007. The parasitoid Copidosoma koehleri provides limited control of the potato tuber moth, Phthorimaea operculella, in stored potatoes. Biological Control 42: 55-60. Ref
  27. Keasar T, Shihadeh S, Shmida S, Majali N, Weil D, Reuven N, 2007. An evaluation of mini-nucleus honeybee hives for pollination of honeydew melons in enclosures. Journal of Apicultural Research 46: 264-268. Ref
  28. Sadeh A, Keasar T, Shmida A., 2007 The carpenter bee Xylocopa pubescens (L.) as an agricultural pollinator in greenhouses. Apidologie 38: 508-517. Ref
  29. Keasar T, Steinberg S, 2008. Evaluation of the parasitoid Copidosoma koehleri for biological control of the potato tuber moth, Phthorimaea operculella, in Israeli potato fields. Biocontrol Science and Technology 18:325-336. Ref
  30. Keasar T, Sadeh A, Shmida A, 2008. Variability in nectar production and yield, and their relation to pollinator visits, in a Mediterranean shrub. Arthropod-Plant Interactions 2: 117-123. Ref
  31. Segoli M, Bouskila A, Harari A, Keasar T., 2009. Developmental patterns in the polyembryonic wasp Copidosoma koehleri. Arthropod Structure and Development, 38: 84-90. Ref
  32. Segoli M, Bouskila A, Harari A, Keasar T, 2009. Brood size in a polyembryonic parasitoid wasp is affected by the relatedness among competing larvae. Behavioral Ecology 20:761-767. Ref
  33. Segoli M, Bouskila A, Harari A, Keasar T, 2009. Host handling time is affected both by previous experience of parasitoid and by previous parasitism of host in a polyembryonic wasp. Journal of Insect Behavior 22: 501-510. Ref
  34. Keasar T, Shmida A, 2009. An evaluation of Israeli forestry trees and shrubs as potential forage plants for bees. Israel Journal of Plant Sciences 57: 49-64. Ref
  35. Arnon R, Keasar T, Hempel De Ibarra N, Cohen D, Shmida A, 2009. Learning of colored targets with vertical and horizontal components by bumblebees (Bombus terrestris L.). Israel Journal of Plant Sciences 57: 193-201. Ref
  36. Keasar T, Sadeh A, Gerchman Y, Shmida A, 2009. The signaling function of an extra-floral display: what selects for signal development? Oikos 118: 1752-1759. Ref
  37. Segoli M, Keasar T, Harari A, Bouskila A, 2009. Limited kin discrimination abilities mediate tolerance toward relatives in polyembryonic wasps. Behavioral Ecology 20: 1262-1267. Ref
  38. Keasar T, 2009. A foreword by the guest editor. Special issue on plant-pollination interactions, Israel Journal of Plant Sciences 57: I.
  39. Segoli M, Keasar T, Bouskila A, Harari A, 2010. Host choice in a polyembryonic wasp depends on the relatedness to a previously parasitizing female. Physiological Entomology 35: 40-45. Ref
  40. Segoli M, Bouskila A, Harari A, Keasar T, 2010. The effect of host starvation on parasitoid brood size in a polyembryonic wasp. Evolutionary Ecology Research 12: 1-9. Ref
  41. Keasar T, Harari AR, Sabatinelli G, Keith D, Dafni A, Shavit O, Zylbertal A, Shmida A, 2010. Red anemone guild flowers as focal places for mating and feeding of Mediterranean glaphyrid beetles. Biological Journal of the Linnean Society 99:808-817. Ref
  42.  Segoli M, Bouskila A, Harari A, Rosenheim J, Keasar T., 2010. Review:  The evolution of polyembryony in parasitoid wasps. Journal of Evolutionary Biology 23: 1807-1819. Ref
  43. Leshem Y, Keasar T, Shmida A, 2011. Female-biased nectar production in the protandrous, hermaphroditic shrub Salvia hierosolymitana: possible reasons and consequences. Australian Journal of Botany, 59: 18-25. Ref
  44. Bar-Shai N, Keasar T, Shmida A, 2011. The use of numerical information by bees in foraging tasks.  Behavioral Ecology, 22: 317-325. Ref
  45. Morag N, Keasar T, Harari A, Bouskila A., 2011. Trans-generational epigenetic effects of maternal rearing density on offspring development time in a parasitoid wasp. Physiological Entomology, DOI: 10.1111/j.1365-3032.2011.00781.x (5 pages). Ref
  46. Morag N, Bouskila A, Segoli M, Rapp O,Keasar T, Harari AR, 2011. The mating status of mothers, and offspring sex, affect clutch size in a polyembryonic parasitoid wasp. Animal Behaviour, 81: 865-870. Ref

SUBMITTED:

  1. Morag N, Bouskila A, Harari A, Keasar T. Low maternal host-encounter rate enhances offspring proliferation in a polyembryonic parasitoid. Submitted to Journal of Evolutionary Biology.
  2. Bar-Shai N, Keasar T, Shmida A. Do solitary bees count to five? Animal Behaviour, in revision.
  3. Gerchman Y, Yerushalmi Y, Dodek I, Petichov R, Lerner A, Keasar T. Beyond pollinator attraction: Extra-floral displays deter herbivores in a Mediterranean annual plant. Submitted to Evolutionary Ecology.
  4. Keasar T, Shmida A, Koplovich A, Gerchman Y, Chinkov N, Katzir G. Sex, drugs and aposematism: tritrophic interactions between anemones, beetles and birds. Submitted to Animal Behaviour.

D. Articles or Chapters in Scientific Books:

PUBLISHED:

*1. Keasar T. Review: Large carpenter bees as agricultural pollinators. 2010. Psyche special issue: Foraging Behavior of Neglected Social Pollinators (ed. by JC Nieh, JC Biesmeijer, C Rasmussen). Ref

E. Discussion Papers

  1. Keasar T, Motro U and Avi Shmida, 1996. Foraging as an Exploratory Activity in Bees: The Effect of Patch VariabilityDiscussion paper no. 118, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  2. Keasar T, Motro U and Shmida A, 1996. Exploration Effort in Foraging Bees Is Enhanced by Clustering of Food Resources. Discussion paper no. 119, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  3. Keasar T, Motro U and Shmida A, 1996. Innate Movement Rules in Foraging Bees: Flight Distances Are Affected by Recent Rewards and Are Correlated with Choice of Flower Type. Discussion paper no. 120, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  4. Bilu Y, Keasar T, Motro U and Shmida A, 1996. Floral Choices of Foraging Bumblebees on Color-Polymorphic Artificial Flowers. Discussion paper no. 121, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  5. Keasar T, Motro U, Shmida A & Shur Y, 1996.  Overnight Memory Retention of Foraging Skills by Bumblebees Is Imperfect. Discussion paper no. 122, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  6.  Goubitz S, Keasar T and Shmida A., 1998 Age-related flower sampling in bumble bees: an analysis of unsuccessful foragers. Discussion paper no. 172, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  7.  Keasar T, Fershtman I, Forotan R and Shmida A., 1998 Learning performance of foraging bees during manipulation of inter-visit intervals. Discussion paper no. 176, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  8. Blarer A, Keasar T and Shmida A., 1998. Does learning of flower size by foraging bumblebees involve concept formation? Discussion paper no. 177, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  9. Ney-Nifle M, Keasar T, Shmida A, 2000. Location and color learning in bumblebees in a two-phase conditioning experiment. ? Discussion paper no. 213, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  10. Rashkovich E, Keasar T, Cohen D, Shmida A., 2000 Choice behavior of bees in two-armed bandit situations: experiments and possible decision rules. Discussion paper no. 226 , Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  11. Bar Shai, N, Samuels R, Keasar T, Motro U, Shmida A., 2003. Flight durations in bumblebees under manipulation of feeding choices. Discussion paper no. 325, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  12. Keasar T, Pollak G, Arnon R, Cohen D, Shmida A, 2006, Honesty of Signaling and Pollinator Attraction: The Case of Flag-Like Bracts. Discussion paper no. 438, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  13. Arnon R, Keasar T, Cohen D, Shmida A, 2006. Vertical Orientation and Color Contrast and Choices by Bumblebees (Bombus terrestris L.). Discussion paper no. 438, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  14. Keasar T, Sadeh A, Shmida A, 2007. Variability in nectar production and yield, and their relation to pollinator visits, in a Mediterranean shrub. Discussion paper no. 458, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  15. Keasar T, Sadeh A, Shmida A, 2007 . The Signaling Function of an Extra-floral Display: What Selects for Signal Development? Discussion paper no. 4 6 8, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  16. Keasar T, Shmida A, Zylbertal A, 2008. Pollination ecology of the red Anemone coronaria (Ranunculaceae): honeybees may select for early flowering. Discussion paper no. 491, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  17. Leshem Y, Keasar T, Shmida A., 2009. Female-biased nectar production in the protandrous, hermaphroditic shrub Salvia hierosolymitana: possible reasons and consequences. Discussion paper no. 494, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  18. Keasar T, Harari AR, Sabatinelli G, Keith D, Dafni A, Shavit O, Zylbertal A,  Shmida A, 2009. Red Anemone Guild Flowers as Focal Places for Mating and Feeding of Mediterranean Glaphyrid Beetles. Discussion paper no. 515, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  19. Bar-Shai N, Keasar T, Shmida A, 2010. The use of numerical information by bees in foraging tasks. Discussion paper no. 576, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.
  20. Bar-Shai N, Keasar T, Shmida A, 2010. Do solitary bees count to five? Discussion paper no. 555, Center for Rationality and Interactive Decision Theory, The Hebrew University, Jerusalem, Israel.

F. Abstracts:

  1. Keasar T, Shmida A and Motro U, 1996. Movement patterns of foraging bumblebees on color-polymorphic artificial flowers. Israel Journal of Zoology 42:69 (conference abstract).
  2. Keasar T, 1997. Foraging as an exploratory activity in bumblebees. Israel Journal of Zoology 43:106 (conference abstract).
  3. Keasar, T, 1997.  Sampling effort in foraging bees is enhanced by clustering of food
    resources. Taborsky, M. and B. Taborsky (Ed.). Advances in Ethology, 32. Contributions to the XXV International Ethological Conference. Blackwell GmbH: Berlin, Germany.
  4. Ney-Nifle M. and Keasar T, 1998 Bumblebees in a changing world: laboratory experiment on color and location learning. Foraging '98 conference abstracts, Santa Cruz, CA, USA.
  5. Keasar T, Ney-Nifle M, Mangel M and Swezey S., 1999. Learning and habitat selection in a parasitoid wasp.  Israel Journal of Zoology 45: 299-232 (conference abstract).
  6. Arnon R, Keasar T, Shmida A, Cohen D, 2000. The adaptive significance of colored bracts. Israel Journal of Zoology, 46: 156-177 (conference abstract).
  7. Samuels R, Keasar T, Motro U, Shmida A, Bar-Shay N, 2000. Flight-time dynamics and the formation of search images by foraging bees.  Israel Journal of Zoology, 46: 156-177 (conference abstract).
  8. Keasar T, 2003. Insects and bacteria vs. Man: which is faster in the evolutionary arms race? Israel Journal of Zoology, 48:161-185 (conference abstract).
  9. Keasar T, Becher O, Kalish A, 2004. Sex ratios in a polyembryonic parasitoid wasp: parental and embryonic influences. Israel Journal of Zoology, 50: 111-112 (conference abstract).
  10. Sheffer N, Keasar T, Libersat F, 2005. Quantitative analysis of oviposition behavior in a parasitoid wasp. Israel Journal of Zoology, 51:  (conference abstract).
  11. Kalish A, Keasar T, Shmida A, 2006. The Carpenter Bee Xylocopa pubescens L. as an Agricultural Pollinator in Greenhouses: a feasibility study. Phytoparasitica, in press.
  12. Kalish A, Keasar T, Shmida A, 2006. The Carpenter Bee Xylocopa pubescens L. as an Agricultural Pollinator in Greenhouses. Israel Journal of Ecology and Evolution 52: 68 (conference abstract).
  13. Segoli M, Bouskila A, Harari A, Keasar T, 2007. Joint parent-offspring control of brood size in a polyembryonic parasitoid wasp. Israel Journal of Ecology and Evolution, in press (conference abstract).
  14. Sadeh A, Shilo M, Ziv Y, Keasar T, 2007. Pollination efficiency of the carpenter bee Xylocopa pubescens (L.) (Hymenoptera: Apidae: Anthophoridae): Social and solitary nesters. Israel Journal of Entomology 37: 422 (conference abstract).
  15. Segoli M, Bouskila A, Harari A, Kfir R, Keasar T, 2007. Evidence for superparasitism and asymmetrical larval competition in a natural population of a polyembryonic parasitoid. Israel Journal of Entomology 37:414 (conference abstract).

G. Other Publications:

  1. Shmida A, Keasar T 1998. Which flower to visit? Galileo 27: 41-47 (Hebrew).Shmida A, Keasar T, 2002. An evaluation of forestry trees as bee forage plants. KKL Research Project Summary (Hebrew).
  2. Keasar T, 2003. Integrated Control of pathogens. Be’Achva TASHSAG 8-9 (Hebrew).
  3. Keasar T, 2007. An overview of the research project “Joint parent-offspring control over brood size in a polyembryonic parasitoid. Be’Achva TASHSAZ 5 (Hebrew).
  4. Shmida A, Keasar T, Zylberthal A, 2008. Red poppies in Israel: coevolution with pollinating beetles. Teva Hadevarim 151, May 2008 issue (Hebrew).

Students and post-docs:
Completed Theses:

Name of Student

Title of Thesis

Degree

Rachel Arnon (with Avi Shmida)

The role of flag-like bracts in Salvia viridis

M.Sc

Adi Sadeh (with Avi Shmida)

The carpenter bee Xylocopa pubescens as an agricultural pollinator for greenhouse crops

M.Sc

Na'ama Morag (with Amos Bouskila

Maternal experience and oviposition decisions in a polyembryonic parasitic wasp.

M.Sc

Michal Segoli (with Amons Bouskila, Ally Harari

Parental and embryonic regulation of brood size in a polyembryonic parasitic wasp.

Ph.D.

Ongoing:

Name of Student

Title of Thesis

Degree

Yael Keynan

Conditioning of parasitoids for improved biocontrol

M.Sc

Chronis Remboulakis

Parental effects in a polyembryonic parasitoid

Post-doc