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William Overholt

Email: billover@ufl.edu

Associate Professor,University of Florida, USA

William Overholt leads a research and extension program at the University of Florida on biological control of invasive plants. Current efforts are focused on Brazilian peppertree, Hydrilla verticillata and tropical soda apple. The work involves exploration for natural enemies in the invasive plants native ranges, host specificity testing, and release and evaluation. Molecular genetic studies and GIS are used to identify source population of invasive plants and to compare climates between exotic and invasive ranges.

Prior to joining the University of Florida, Dr. Overholt spent 11 years at the International Center of Insect Physiology and Ecology in Nairobi, Kenya where he led a regional program on biological control of an invasive insect pest of maize.

Curriculum Vitae

Name: Dr. William Overholt

Country of birth: United States

Nationality:  

Position Title: Associate Professor

Institution: University of Florida, USA

Contact Address:

Biological Control Research and Containment Laboratory 2199 South Rock Road Fort Pierce, FL 34945-3138 USA

Email: billover@ufl.edu

Tel: +001 772-468-3922 x143

Specialty Area:

-          Entomology

Education:

1977  B.S., Agriculture, Ohio State University, USA

1989  Ph.D., Entomology, Texas A&M University, USA.

Positions held (since terminal degree):

2002 to date   Assistant Professor, Department of Entomology and Nematology, Indian River Research and Education Center, University of Florida, USA

1991 - 2002  Program Leader and Principal Scientist, International Centre of Insect Physiology and Ecology (ICIPE), Nairobi, Kenya.

1989 - 1991  Technical Advisor (Pest management), USAID Science and Technology Bureau, Washington, D. C.

1989 - 1989  Technical Advisor (Entomology), USAID Desert Locust Task Force, Washington, D. C.

1985 - 1989  Graduate Research Assistant, Department of Entomology, Texas A&M University, College Station, Texas.

Expertise:

-          Biological control of invasive plants

Honors and Awards (since terminal degree):

A selection of major research accomplishments: Discoveries and first reports

A Selection of refereed journal publications (2002-present)

Mohamed H. M., Z.R. Khan, W.A. Overholt and D.K. Elizabeth. 2005. Behavior and biology of Chilo partellus (Lepidoptera:Pyralidae) on maize and wild gramineous plants. International Journal of Tropical Insect Science 24: 287-297.

Morgan E. C. and W. A. Overholt. 2005. New records of invasive exotic plant species in St. Lucie county Florida. Castanea 70: 59-62.

Morgan E. C. and W. A. Overholt. 2005. Potential allelopathic effects of Brazilian pepper (Schinus terebinthifolius Raddi Anacardiaceae) aqueous extract on germination and growth of selected Florida native plants. Journal of the Torrey Botanical Society. 132(1):11-15.

Ngumbi E., A. J. Ngi-song, L. Wadhams, J. Pickett, W. A. Overholt, R. Torto and B. Torto. 2005. Responses of the stem borer larval endoparasitioid Cotesia flavipes (Hymenoptera: Braconidae) to plant derived synomones: laboratory and field cage experiments. Biocontrol Science and Technology 15:271-279.

Midega C. A. O., C. K. P. O. Ogol and W. A. Overholt. 2005. Effect of Agroecosystem diversification through agroforestry and intercroping on activity of natural enemies of maize stemborers at the Kenyan coast. International Journal of Tropical Insect Science 24: 280-286

Overholt W. A., S. M. L. Ewe, R. Diaz, E. C. Morgan and O. E. Moeri. 2004. Feeding effects of Ischnodemus variegatus (Hemiptera: Blissidae) on photosynthesis and growth of Hymenachne amplexicaulis (Poaceae). Florida Entomologist 87: 312-316.

Chinwada P., W. A. Overholt, C. O. Omwega and J. M. Mueke. 2004. Biology of Sturmiopsis parasitica (Diptera: Tachinidae) and suitability of three cereal stem borers (Lepidoptera: Crambidae, Noctuidae) for its development. Annals of the Entomological Society of America 97: 153-160.

Kalyebi A., W.A. Overholt, S. Sithanantham, J.M. Mueke, S.A. Hassan and F. Schulthess. 2004. Functional response of six indigenous trichogrammatid egg parasitoids (Hymenoptera: Trichogrammatidae) in Kenya: Influence of temperature and relative humidity. Biocontrol Science and Technology 32: 164-171.

Getu E., W. A. Overholt and E. Kairu 2004. Comparative studies on the influence of relative humidity and temperature on life table parameters of two populations of Cotesia flavipes (Hymenoptera: Braconidae). Biocontrol Science and Technology 14: 595-605.

Mochiah M. B., A. J. Ngi-Song, W. A. Overholt and R. Stouthamer. 2003. Variation in encapsulation sensitivity of Cotesia sesamiae (Cameron) (Hymenoptera: Braconidae) biotypes to Busseola fusca Fuller (Lepidoptera: Noctuidae). Entomologia Experimentalis et Applicata 105: 111-118.

Mochiah M. B., A. J. Ngi-Song, W. A. Overholt and M. Botchey. 2003. Variation in total and differential haemocyte count of encapsulation sensitivity of Busseola fusca (Lepidoptera: Noctuidae) parasitized by two biotypes of Cotesia sesamiae (Hymenoptera: Braconidae) and larval growth responses. Environmental Entomology 32(2): 247-255.

Khan Z. R., A. Hassanali, T. M. Khamis, W. A. Overholt, A. M. Hooper, J. A. Pickett, L. J. Wadhams, and C. M. Woodcock. 2003. Control of witchweed, Striga hermonthica, by intercropping with Desmodium spp. and the mechanism defined as allelopathic. Journal of Chemical Ecology 28: 1871-1885.

Bekele J., A. J. Ngi-Song and W. Overholt. 2003. Olfactory responses of Cotesia flavipes (Hymenoptera: Braconidae) to target and non-target Lepidoptera and their host plants. Biological Control 28: 360-367.

Chinwada P., W. A. Overholt, C. O. Omwega and J. M. Mueke. 2003. Geographic differences in host acceptance and suitability of two Cotesia sesamiae populations in Zimbabwe. Biological Control 28: 354-359.

Cole T. J., M. S. Ram, F. E. Dowell, C. O. Omwega, W. A. Overholt and S. B. Ramaswamy. 2003. Near-infrared spectroscopic method to identify Cotesia flavipes and Cotesia sesamiae (Hymenoptera: Braconidae). Annals of the Entomological Society of America 96: 865-869.

Gohole L. S., W. A. Overholt, Z. R. Khan, J. A. Pickett and L. E. M. Vet. 2003. Effects of molasses grass, Melinis minutiflora volatiles on the foraging behaviour of the cereal stemborer parasitoid, Cotesia sesamiae. Journal of Chemical Ecology 29: 731-745.

Gohole L.S., W. A. Overholt, Z. R. Khan and L. E. M. Vet. 2003. Role of volatiles emitted by host and non-host plants in the foraging behaviour of Dentichasmias busseolae, a pupal parasitoid of the spotted stemborer Chilo partellus. Entomologia Experimentalis et Applicata 107: 1-9.

Emana G., W.A. Overholt and E. Kairu. 2003. Comparative studies on the influence of relative humidity and temperature on the developmental time of two populations of Cotesia flavipes. Ethiopian Journal of Biological Sciences 2: 49-60.

Mohamed S. A., W. A. Overholt, R. A. Wharton, S. A. Lux and E. M. Eltoum. 2003. Host specificity of Psyttalia cosyrae (Hymenoptera: Braconidae) and the effect of different host species on parasitoid fitness. Biological Control 28: 155-163.

Getu E., W. A. Overholt and C. O. Omwega. 2003. Evidence of the establishment of Cotesia flavipes Cameron (Hymenoptera: Braconidae), a parasitoid of cereal stemborers, and its host range expansion in Ethiopia. Bulletin of Entomological Research 93: 125-129.

Zhou G., W. A. Overholt and S.W. Kimani-Njogu. 2003. Species richness, parasitism and trophic relationships in an assemblage of parasitoids attacking maize stem borers in coastal Kenya. Ecological Entomology 28: 109-118.

Gitonga L. M., W. A. Overholt, B. Lohr, J. K. Magambo and J. M. Mueke. 2002. Functional response of Orius albidipennis (Hemiptera: Anthocoridae) to Megalurothrips sjostedti (Thysanoptera : Thripidae). Biological Control 24: 1-6.

Gitonga L. M., B. Lohr, W. A. Overholt, J. K. Magambo and J. M. Mueke. 2002. Temperature dependent development of Megalurathrips sjostedti and Frankliniella occidentalis (Thysanoptera: Thripidae). African Entomology 10: 325-331.

Gitonga L. M., B. Lohr, W. A. Overholt, J. K. Magambo, and J. M. Mueke. 2002. Effects of temperature on the development of Orius albidipennis Reuter, a predator of the Africa legume flower thrips, Megalaurothrips sjostedti Trybom. Insect Science and Its Application 22: 215-220.

Kfir R., W. A. Overholt, A. Polaszek and Z. R. Khan. 2002. Biology and management of economically important lepidopteran cereal stem borers in Africa. Annual Review of Entomology 47: 701- 731.

Mbapila J. C., W. A. Overholt and H. Y. Kayumbo. 2002. Comparative development and population growth of an exotic cereal stemborer, Chilo partellus (Swinhoe) and an ecologically similar congener, Chilo orichalcociliellus (Strand) (Lepidoptera: Crambidae). Insect Science and Its Application 22: 21-27.

Mochiah M. B., A. J. Ngi-Song, W. A. Overholt and A. Botchey. 2002. Effects of calyx fluid from a population of Cotesia sesamiae (Cameron) (Hymenoptera: Bracondiae) on the immune system of its host Busseola fusca Fuller (Lepidoptera: Noctuidae). Insect Science and Its Application 22: 81-85.

Mochiah M. B., A. J. Ngi-Song, W. A. Overholt and R. Stouthamer. 2002. Wolbachia Infection in Cotesia sesamiae (Hymenoptera: Braconidae) causes cytoplasmic incompatibility: Implications for biological control. Biological Control 25: 74-80.

Sallam M. N., W. A. Overholt and E. Kairu. 2002. Intraspecific and interspecific competition between Cotesia flavipes and Cotesia sesamiae (Hymenoptera: Braconidae), gregarious larval endoparasitoids of lepidopteran stemborers. Biocontrol Science and Technology 12: 493-506.

Songa J. M., W. A. Overholt, J. M. Mueke and R. O. Okello. 2002. Farmers' perceptions of aspects of maize production systems and pests in semi-arid eastern Kenya: factors influencing occurrence and control of stemborers. International Journal of Pest Management 48: 1-11.

Songa J. M., W. A. Overholt, J. M. Mueke and R. O. Okello. 2002. Regional distribution of lepidopteran stemborers and their parasitoids among wild grasses in the semi-arid eastern Kenya. African Crop Science Journal 10: 183-194.

Songa J. M., W. A. Overholt, R. O. Okello and J. M. Mueke. 2002. Control of lepidopteran stem borers in maize by indigenous parasitoids in semi-arid areas of eastern Kenya. Biological Agriculture and Horticulture 20: 77-90.

Book chapters:

Cardwell K., D. E. Conlong, R. Goebel, Z. R. Khan, R. Kfir, W. A. Overholt, F. Schulthess and M. Setamou. 2004. Gramineous stemborers in Africa. pp. 990-997 In J. L. Capinera (ed.), Encyclopedia of Entomology. Kluwer Academic, Dordrecht, The Netherlands

Overholt W. A., D. E. Conlong, R. Kfir, F. Schulthess and M. Setamou. 2003. Biological control of gramineous lepidopteran stemborers in sub-Saharan Africa. pp. 131-144. In P. Neuenschwander and C. Borgemeister (eds.), Biological control in IPM Systems in Africa. CAB International, Wallingford, Oxon, UK.

Braima J., P. Neuenschwander, R. Markham, P. Anderson, A. Brown, W. A. Overholt, Z. R. Khan, K. Makkouk and A. Embechebe. 2003. Bridging the gap with the CGIAR systemwide programme on integrated pest management. pp. 419-434. In K. Maredia and D. Dokouo (eds.) Integrated pest management in the global arena. CAB International, Wallingford, Oxon, UK.

Khan Z. R., W. A. Overholt and A. Mengech. 2003. Integrated pest management case studies from ICIPE. pp. 441-452. In K. Maredia and D. Dokouo (eds.) Integrated pest management in the global arena. CAB International, Wallingford, Oxon, UK.

Overholt W. A. 1998. Biological control. pp 349-362. In A. Polaszek (ed.) African cereal stem borers: economic importance, taxonomy, natural enemies and control. CAB International, Wallingford, Oxon, UK. 530 pp.

Invited presentations at major international conferences (2002-present-Maximum 8)

Research Grants (2004 – present):

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This database is supported with funding from the Bill & Melinda Gates Foundation