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Cornell University Department of Entomology

Ann Hajek


Ann E. Hajek

Professor

University of California, Berkely, 1984
Insect pathology; biological control and population ecology

6126 Comstock Hall, Ithaca, NY 14853-2601
Phone: 607.254.4902
Fax: 607.255.0939
Email: aeh4@cornell.edu
Website: http://www.entomology.cornell.edu/Faculty_Staff/Hajek

Table of Contents

Professional Overview & Objectives

Emphasis in my program is on pathogens of invertebrates, predominantly focusing on interactions between pathogens and their insect hosts. My interests are broad, ranging from systematics to population genetics, immune responses, basic biologies of pathogens, interactions between hosts and pathogens and epizootiology. I have worked extensively with a fungal pathogen first seen in North America that has been providing natural control of gypsy moth, a major pest of northeastern forests for over 100 years. While this Japanese pathogen is not always providing complete control everywhere, it has been maintaining many gypsy moth populations in central New York at low densities since it was first reported in North America. In other areas, infrequent outbreaks for shorter periods have occurred. At present, our studies are focusing on spatial and temporal variability in activity of E. maimaiga and the reasons behind low levels of activity in localized areas. Among our other studies on this system, host specificity studies in the laboratory and field have shown that this pathogen provides an excellent example of successful biological control without non-target effects. We have also studied the population genetics of this fungus as well as spore dormancy, the latter toward potential development of this fungus as a biological control product. Our studies with Asian longhorned beetle have been directed toward use of an entomopathogenic fungus for control of this invasive from China. We have been developing a novel application method that provides a means for applying insect pathogenic fungi that remain viable for several months, something previously unheard of. Recent studies have demonstrated decreased fecundity in females before death and the fact that placing fungal bands around trees leads to low levels of environmental contamination both from beetles walking across them and from abiotic conditions. A newer project in the laboratory involves studies of fungal symbionts of the new invasive woodwasp Sirex noctilio. Additional studies in the lab include: the changes in behavior of fungal-infected insects, the effect of density on susceptibility of caterpillars to virus, and dispersal of gypsy moth pathogens. Throughout all of these projects, we strive to learn new information about insect pathogens and their relations to hosts that also answer basic and conceptual questions in the ecology of infectious disease.

Education

Year Degree Institution
1984
 Ph.D.
 University of California, Berkley
1980 M.S. University of California, Berkley
1974 B.A./B.S. University of California, Berkley

Academic Ranks

Professor: April 1, 2005
Associate Professor: July 1, 2000
Assistant Professor: September 1, 1994

Areas of Expertise

 Invertebrate pathology, biological control, epizootiology, insect ecology

Courses Taught

Entom 2770 Invasive Species and Natural Enemies
Entom 4630 Invertebrate Pathology
Entom 6700 Seminar in Biological Control
Entom 7670 Current Topics in Entomology

Publications

Referreed journal articles

Hajek, A.E., J. Lund, M.T. Smith. 2008. Reduction in fitness of female Asian longhorned beetle (Anoplophora glabripennis) infected with Metarhizium anisopliae. J. Invertebr. Pathol., doi:10.1016/j.jip.2007.12.003

Dubois, T., J. Lund, L.S. Bauer, A.E. Hajek. 2007. Virulence of entomopathogenic hypocrealean fungi infecting Anoplophora glabripennis. BioControl DOI 10.1007/s10526-007-9112-2.

Hajek, A.E., J.J. Hannam, C. Nielsen, A.J. Bell, J.K. Liebherr. 2007. Distribution and abundance of Carabidae (Coleoptera) associated with soybean aphid (Hemiptera: Aphididae), populations in central New York. Ann. Entomol. Soc. Amer. 100: 876-886.

Hajek, A.E., D.M. Kalb. 2007. Suitability of Acer saccharum and Acer pensylvanicum for rearing Anoplophora glabripennis (Coleoptera: Cerambycidae). Can. Entomol. 139: 751-755.

Reilly, J.R., A.E. Hajek. 2007. Density-dependent resistance of the gypsy moth, Lymantria dispar to its nucleopolyhedrovirus, and the consequences for population dynamics. Oecologia, doi:10.1007//s00442-007-0871-3.

Filotas, M.F., A.E. Hajek. 2007. Variability in thermal responses among Furia gastropachae isolates from different geographic origins. J. Invertebr. Pathol. 96: 109-117.

Castrillo, L.A., L. Thomsen, P. Juneja, A.E. Hajek. 2007. Detection and quantification of Entomophaga maimaiga resting spores in forest soil using real-time PCR. Mycol. Res. 111: 324-331.

Hajek, A.E., M. L. McManus, I. Delalibera Junior. 2007. A review of introductions of pathogens and nematodes for classical biological control of insects and mites. Biol. Control 41: 1-13.

Delalibera Junior, I., C. G. B. Demetrio, B. F. J. Manly, and A. E. Hajek. 2006. Effect of relative humidity and origin of isolates of Neozygites tanajoae (Zygomycetes: Entomophthorales) on production of conidia from cassava green mite, Mononychellus tanajoae (Acari: Tetranychidae) cadavers. Biol. Control 39: 489-496.

Filotas, M. J., J. D. Vandenberg, and A. E. Hajek. Dose-response and temperature-related susceptibility of the forest tent caterpillar (Lepidoptera: Lasiocampidae) to the entomopathogenic fungus Furia gastropachae (Raciborski) (Zygomycetes: Entomophthorales). Biol. Contr. 39: 218-224.

Nielsen, C., and A.E. Hajek. 2006. Diurnal pattern of death and sporulation of Entomophaga maimaiga-infected Lymantria dispar. Entomol. Exp. Appl. 118: 237-243.

Hajek, A.E., B. Huang, T. Dubois, M. T. Smith , and Z. Li. 2006. Field studies of control of Anoplophora glabripennis (Coleoptera: Cerambycidae) using fiber bands containing the entomopathogenic fungi Metarhizium anisopliae and Beauveria brongniartii. Biocontr. Sci. Technol. 16: 329-343.

Nielsen, C., M. Keena, A.E. Hajek. 2005. Virulence and fitness of the fungal pathogen Entomophaga maimaiga in its host Lymantria dispar, for pathogen and host strains originating from Asia, Europe and North America. J. Invertebr. Pathol. 89: 232-242.

Nielsen, C., and A.E. Hajek. 2005. Control of invasive soybean aphid, Aphis glycines (Hemiptera: Aphididae) populations by existing natural enemies in New York State. Environ. Entomol. 34: 1036-1047.

Nielsen, C., M.G. Milgroom, A.E. Hajek. 2005. Genetic diversity in the gypsy moth fungal pathogen Entomophaga maimaiga from founder populations in North America and source populations in Asia. Mycol. Res. 109: 941-950.

Hajek, A.E., R.T. Curtiss, J.K. Liebherr. 2004. Characters differentiating male from female Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae). Proc. Entomol. Soc. Wash. Proc. Entomol. Soc. Wash. 106: 928-931.

Filotas, M. J., and A. E. Hajek. 2004. Influence of temperature and moisture on infection of forest tent caterpillars (Lepidoptera: Lasiocampidae) by the entomopathogenic fungus Furia gastropachae (Zygomycetes: Entomophthorales). Environ. Entomol. 33: 1127-1136.

Delalibera Jr., I. & A.E. Hajek. 2004. Pathogenicity and specificity of isolates of Neozygites tanajoae and Neozygites floridana (Zygomycetes: Entomophthorales) pathogenic to the cassava green mite. Biol. Contr. 30: 608-616.

Dubois, T., Z. Li, H. Jiafu, and A.E. Hajek. 2004. Efficacy of fiber bands impregnated with Beauveria brongniartii cultures against the Asian longhorned beetle, Anoplophora glabripennis (Coleoptera: Cerambycidae). Biol. Contr. 31: 320-328.

Hajek, A.E., N.W. Siegert, M.M. Wheeler, and D.G. McCullough. 2004. Using bioassays to predict abundance of Entomophaga maimaiga resting spores in soil. J. Invertebr. Pathol. 86: 61-64.

Delalibera Jr., I., A.E. Hajek, and R.A. Humber. 2004. Preservation of in vitro cultures of the mite pathogenic fungus Neozygites tanajoae. Can. J. Microbiol. Can. J. Microbiol 50: 579-586.

Delalibera Jr., I., A.E. Hajek, and R.A. Humber. 2004. Neozygites tanajoae sp. nov., a pathogen of the cassava green mite. Mycologia 96: 1002-1009.

Hajek, A.E., J.S. Strazanac, M.M Wheeler, F. Vermeylen, and L. Butler. 2004. Persistence of the fungal pathogen Entomophaga maimaiga and its impact on native Lymantriidae. Biol. Contr. 30: 466-471.

Dubois, T., A.E. Hajek, H. Jiafu, and Z. Li. 2004. Evaluating the efficiency of entomopathogenic fungi against the Asian longhorned beetle, Anoplophora glabripennis (Coleoptera: Cerambycidae), by using cages in the field. Environ. Entomol. 33: 62-74.

Delalibera Jr., I., A.E. Hajek, and R.A. Humber. 2003. Use of cell culture media for cultivation of the mite pathogenic fungi Neozygites tanajoae and Neozygites floridana. J. Invertebr. Pathol. 84: 119-127.

Nielsen, C., A.E. Hajek, R.A. Humber, J. Bresciani, and J. Eilenberg. 2003. Soil as an environment for winter survival of aphid-pathogenic Entomophthorales. Biological Control 28: 92-100.

Hajek, A.E., A.B. Jensen, L. Thomsen, K.T. Hodge, and J. Eilenberg. 2003. Using PCR-RFLP to investigate relations among species in the entomopathogenic genera Eryniopsis and Entomophaga. Mycologia 95: 262-268.

Hajek, A.E., and C.C. Eastburn. 2003. Attachment and germination of Entomophaga maimaiga conidia on host and non-host larval cuticle. J. Invertebr. Pathol. 82: 12-22.

Filotas, M.J.F., A.E.Hajek, and R.A. Humber. 2003. Prevalence and biology of Furia gastropachae (Zygomycetes: Entomophthorales) in populations of the forest tent caterpillar (Lepidoptera: Lymantriidae). Can. Entomol. 135: 359-378.

Lopez Lastra, C.C., A.E. Hajek, and R.A. Humber. 2002. Comparing methods for preservation of cultures of entomopathogenic fungi. Can. J. Bot. 80: 1126-1130.

Hajek, A.E., M.J. Filotas, D.C. Ewing. 2002. Formation of appressoria by two species of lepidopteran-pathogenic Entomophthorales. Can. J. Bot. 80: 220-225.

Hajek, A.E., C.C. Eastburn, C.I. Davis, and F. Vermeylen. 2002. Deposition and germination of conidia of the entomopathogen Entomophaga maimaiga infecting gypsy moth, Lymantria dispar. J. Invertebr. Pathol. 79: 37-43.

Lopez Lastra, C.C., D.M. Gibson, and A.E. Hajek. 2001. Survival and differential development of Entomophaga maimaiga and Entomophaga aulicae (Zygomycetes: Entomophthorales) in Lymantria dispar hemolymph. J. Invertebr. Pathol. 78: 201-209.

Klingen, I., A. Hajek, A. Renwick, and R. Meadow. 2002. Effect of brassicaceous plants on the survival and infectivity of insect pathogenic fungi. BioControl 47: 411-425.

Dubois, T., A.E. Hajek, and S. Smith. 2002. Methods for rearing the Asian longhorned beetle, Anoplophora glabripennis (Coleoptera: Cerambycidae) on artificial diet. Ann. Entomol. Soc. Amer. 95: 223-230.

Eilenberg, J., A. Hajek, and C. Lomer. 2001. Suggestions for unifying the terminology in biological control. BioControl 46: 387-400.

Hajek, A.E., and C.C. Eastburn. 2001. Effect of host insects on activation of Entomophaga maimaiga resting spores. J. Invertebr. Pathol. 77: 290-291.

Lopez Lastra, C.C., A.E. Hajek, and R.A. Humber. 2001. Effects of two cryopreservation techniques on viability and pathogenicity of entomophthoralean fungi. Can. J. Bot. 79: 861-864.

Jensen, M.A., J.E. Losey, and A.E. Hajek. 2001. Altered behavior and distribution of pea aphids, Acyrthosiphon pisum (Homoptera: Aphididae), infected with Pandora neoaphidis (Zygomycetes: Entomophthorales). BioControl 46: 337-343.

Hajek, A.E., M.M. Wheeler, C.C. Eastburn, and L.S. Bauer. 2001. Storage of resting spores of the gypsy moth fungal pathogen, Entomophaga maimaiga. Biocontrol Sci. Technol. 11: 637-647.

Hajek, A.E. 2001. Larval behavior in Lymantria dispar increases risk of fungal infection. Oecologia 126: 285-291.

Pilarska, D., M. McManus, A.E. Hajek, F. Hérard, F.E. Vega, P. Pilarska, and G. Markova. 2000. Introduction of the entomopathogenic fungus Entomophaga maimaiga Hum., Shim. & Sop. (Zygomycetes: Entomophthorales) to a Lymantria dispar (L.) (Lepidoptera: Lymantriidae) population in Bulgaria. Anz. Schadlingsk. 73: 125-126.

Hajek, A.E., L. Butler, J.K. Liebherr, and M.M. Wheeler. 2000. Risk of infection by the fungal pathogen Entomophaga maimaiga among Lepidoptera on the forest floor. Environ. Entomol. 29: 645-650.

Hajek, A.E., M. Shimazu, and B. Knoblauch. 2000. Isolating Entomophaga maimaiga using resting spore-bearing soil. J. Invertebr. Pathol. 75: 298-300.

Kogan, P.H., and A.E. Hajek. 2000. Formation of azygospores by the insect pathogenic fungus Entomophaga maimaiga in cell culture. J. Invertebr. Pathol. 75: 193-201.

Dahlsten, D.L., R.L. Zuparko, A.E. Hajek, D.L. Rowney, and S.H. Dreistadt. 1999. Long term sampling of Eucallipterus tiliae (Homoptera: Drepanosiphidiae) and associated natural enemies in a northern California site. Environ. Entomol.28: 845-850.

Hajek, A.E., C. Olsen, and J.S. Elkinton. 1999. Dynamics of airborne conidia of the gypsy moth (Lepidoptera: Lymantriidae) fungal pathogen Entomophaga maimaiga (Zygomycetes: Entomophthorales). Biol. Contr. 16: 111-117.

Hajek, A.E., and R.E. Webb. 1999. Inoculative augmentation of the fungal entomopathogen Entomophaga maimaiga as a homeowner tactic to control gypsy moth (Lepidoptera: Lymantriidae). Biol. Contr. 14: 11-18.

Malakar, R., J.S. Elkinton, A.E. Hajek, and J.P. Burand. 1999. Within-host interactions of Lymantria dispar L. (Lepidoptera: Lymantriidae) nucleopolyhedrosis virus (LdNPV) and Entomophaga maimaiga (Zygomycetes: Entomophthorales). J. Invertebr. Pathol. 73: 91-100.

Bidochka, M.J., and A.E. Hajek. 1998. A non-permissive entomophthoralean fungal infection increases activation of insect prophenoloxidase. J. Invertebr. Pathol. 72: 231-238.

Hajek, A.E., L. Bauer, M.L. McManus, and M.M. Wheeler. 1998. Distribution of resting spores of the Lymantria dispar pathogen Entomophaga maimaiga in soil and on bark. BioControl 43: 189-200.

Hajek, A.E., K.M. Tatman, P.H. Wanner, and M.M. Wheeler. 1998. Location and persistence of cadavers of gypsy moth, Lymantria dispar, containing Entomophaga maimaiga azygospores. Mycologia 90: 754-760.

Dwyer, G., J.S. Elkinton, and A.E. Hajek. 1998. Spatial scale and the spread of a fungal pathogen of gypsy moth. Amer. Nat. 152: 485-494.

Books

Wraight, S.P. and A.E. Hajek. 2008. Use of arthropod pathogens for integrated pest management. In (E.B. Radcliffe, W.D. Hutchison & R.E. Cancelado, Eds.) Integrated Pest Management. Cambridge University Press, Cambridge, UK (in press). [Invited book chapter].

Hajek, A.E., T. Dubois, J. Lund, M. Smith, L. Bauer, and Z. Li. 2007. Developing fungal bands for control of Asian longhorned beetle, Anoplophora glabripennis, in the U.S. J. Anhui Agric. Univ. 34: 149-156. [Invited review].

Hajek, A.E., and L. S. Bauer. 2007. Microbial control of wood-boring insects attacking forest and shade trees, pp. 505-525. In (L.A. Lacey & H.K. Kaya, Eds.) Field Manual of Techniques in Invertebrate Pathology, 2nd edn. Springer, Dordrecht, Netherlands [Invited review].

Hajek, A.E., I. Delalibera Jr., and M.L. McManus. 2007. Introduction of exotic pathogens and documentation of their establishment and impact, pp. 299-325. In (L.A. Lacey & H.K. Kaya, Eds.) Field Manual of Techniques in Invertebrate Pathology, 2nd edn. Springer, Dordrecht, Netherlands [Invited review].

Hajek, A.E., and M.S. Goettel. 2007. Guidelines for evaluating effects of entomopathogens on non-target organisms, pp. 815-833. In (L.A. Lacey & H.K. Kaya, Eds.) Field Manual of Techniques in Invertebrate Pathology. Springer, Dordrecht, Netherlands [Invited review].

Hajek, A. E., J. R. Fuxa, and Y. Kunimi. 2007. Microorganisms associated with soil arthropods, pp. 769-780. In C. J. Hurst, R. L. Crawford, J. L. Garland, D. A. Lipson, A. L. Mills, and L. D. Stetzenbach (ed.), Manual of Environmental Microbiology, 3rd ed. ASM Press, Washington, D.C. [Invited review].

Hajek, A.E. 2007. Asian longhorned beetle: Ecology and control, pp. 21-24. In (D. Pimentel, Ed.) Encyclopedia of Pest Management, Vol. II. CRC Press, Taylor & Francis Group, Boca Raton, FL [Invited review].

Hajek, A.E. 2007. Classical biological control of gypsy moth: Introduction of the entomopathogenic fungus Entomophaga maimaiga into North America, pp. 53-62. In (C. Vincent, M. Goettel, G. Lazarovits, Eds.) Biological Control: International Case Studies. CABI Publ., UK [Invited review].

Hajek, A. E., M. L. McManus & I. Delalibera Junior. 2005. Catalogue of Introductions of pathogens and nematodes for classical biological control of insects and mites. USDA, For. Serv. FHTET-2005-05. 59 pp.

Hajek, A.E. 2004. Natural Enemies: An Introduction to Biological Control. Cambridge University Press, Cambridge, UK [single-authored textbook]

Hokkanen, H.M.T., and A.E. Hajek (editors). 2003. Environmental Impacts of Microbial Insecticides. Kluwer Academic Publishers, Dordrecht, NL.

Book chapters / Reviews

Roy, H.E., D.C. Steinkraus, J. Eilenberg, A.E. Hajek, and J.K. Pell. 2006. Bizarre interactions and endgames: Entomopathogenic fungi and their arthropod hosts. Annu. Rev. Entomol. 51: 331-357.

Hajek, A.E., J.S. Strazanac, M.M. Wheeler, L. Butler. 2005. Chapter 5: Entomophaga maimaiga studies, pp. 45-49. In (J.S. Strazanac & L. Butler, Eds.) Long-term Evaluation of the Effects of Bacillus thuringiensis kurstaki, Gypsy Moth Nucleopolyhedrosis Virus Product Gypchek, and Entomophaga maimaiga on Nontarget organisms in Mixed Broadleaf-Pine Forests in the Central Appalacians. U.S.D.A., Forest Service, FHTET-2004-14. 81 pp.

Hajek, A.E., I. Delalibera Jr., and L. Butler. 2003. Entomopathogenic fungi as classical biological control agents, pp. 15-34. In (H.M.T. Hokkanen & A.E. Hajek, Eds.) Environmental Impacts of Microbial Insecticides. Kluwer Academic Publishers, Dordrecht, NL.

Hajek, A.E. 2002. Biological control of insects and mites, pp. 57-60. In (D. Pimentel, Ed.) Encyclopedia of Pest Management. Marcel Dekker, NY [Invited review]

Hajek, A.E., S.P. Wraight, and J.D. Vandenberg. 2001. Control of arthropods using pathogenic fungi, pp. 309-347. In (S.B. Pointing & K.D. Hyde, Eds.) Bio-Exploitation of Fungi. Fungal Diversity Press, Hong Kong [Invited review.].

Pell, J., D. Steinkraus, J. Eilenberg, and A. Hajek. 2001. Exploring the potential of Entomophthorales in integrated crop management, pp. 71-167. In (T. Butt, C. Jackson, and N. Magan, Eds.) Fungal Biocontrol Agents: Progress, Problems and Potential. Kluwer, Dordrecht, Netherlands [Invited review.]

Goettel, M.S., A.E. Hajek, J.P. Siegel, and H.C. Evans. 2001. Safety of fungal biocontrol agents, pp. 347-375. In (T. Butt, C. Jackson, and N. Magan, Eds.) Fungal Biocontrol Agents: Progress, Problems and Potential. Kluwer, Dordrecht, Netherlands [Invited review.]

Goettel, M.S., and A.E. Hajek. 2001. Evaluation of non-target effects of pathogens used for management of arthropods, pp. 81-97. In (E. Wajnberg, J.K. Scott & P.C. Quimby, Eds.) Evaluating Indirect Ecological Effects of Biological Control. CABI Publ., Wallingford, Oxon, UK.

Hajek, A.E., and L. Butler. 2000. Predicting the host range of entomopathogenic fungi, pp. 263-276. In (P.A. Follett & J.J. Duan, Eds.) Non-target Effects of Biological Control. Kluwer, Dordrecht, Netherlands [Invited review.]

Hajek, A.E., I. Delalibera Jr., and M.L. McManus. 2000. Introduction of exotic pathogens and documentation of their establishment and impact, pp. 339-369. In (L.A. Lacey & H.K. Kaya, Eds.) Field Manual of Techniques in Invertebrate Pathology. Kluwer, Dordrecht, Netherlands [Invited review.].

Hajek, A.E., and M.S. Goettel. 2000. Guidelines for evaluating effects of entomopathogens on non-target organisms, pp. 847-868. In (L.A. Lacey & H.K. Kaya, Eds.) Field Manual of Techniques in Invertebrate Pathology. Kluwer, Dordrecht, Netherlands [Invited review.].

Hajek, A.E. 1999. Pathology and epizootiology of the lepidoptera-specific mycopathogen Entomophaga maimaiga. Microbiol. & Molecul. Biol. Rev. 63: 814-835 [Invited review.]