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CONTACT INFORMATION |
Research Entomologist
Phone: 406.433.9406
Fax: 406.433.5038
E-mail: dbranson[at]sidney.ars.usda.gov |
EDUCATION |
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B.S. Biology |
1988 |
Bryan College, Dayton,
TN |
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M.S. Biology |
1992 |
University of
Michigan, Ann Arbor, MI |
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Ph. D. Ecology |
2001 |
Utah State University,
Logan, UT |
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CURRENT RESEARCH |
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Grasshoppers are often
the dominant herbivore in western U.S. grasslands, both in terms of
herbivore biomass and plant biomass consumed. In much of the Great
Plains, rangeland grasshopper populations tend to increase with both
livestock stocking rates and dry conditions. However, little research
has examined preventative strategies that might reduce grasshopper
outbreaks. To prevent grasshopper outbreaks through habitat management,
we first need to better understand the ecological interactions
underlying outbreaks. Since grazing management systems differ in how
they manipulate the timing, rate, or degree of plant defoliation by
livestock, I am examining how certain types of grazing management may
create unfavorable habitats for grasshoppers and reduce outbreaks.
Although grasshoppers often reduce the amount of rangeland vegetation in
a given year, we don’t understand how grasshoppers affect longer-term
vegetation production. I am examining the effects of grasshopper herbivory on nutrient cycling and grassland productivity.
Ongoing research projects are examining the following:
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How
often and what types of grazing management reduce grasshopper
outbreaks in replicated grazing management experiments in ND and NE.
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Combined
effects of fire and livestock grazing on grasshopper populations and
rangeland vegetation.
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Mechanisms responsible for differing grasshopper population dynamics
under particular grazing management systems.
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What
ecosystem characteristics allow grasshopper herbivory to be beneficial
or detrimental to rangeland production.
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Role of
grasshopper herbivory in rangeland nutrient cycling.
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Role of
grasshopper herbivory on the invasibility of exotic dominated
grasslands.
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Effects
of nymph-overwintering grasshoppers on plant production and egg-overwintering
grasshoppers.
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RESEARCH EXPERIENCE |
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I joined the USDA-Agricultural Research
service as a Research Entomologist in 1998. Prior to joining ARS, I
conducted my dissertation research in ecology at Utah State University.
My research focused on determining the importance of grasshopper
population density, resource availability, and parasitism on life
history variation and population dynamics of rangeland grasshoppers. I
also worked at Utah State University on studies examining if grasshoppers diminish grassland productivity and the dominance of
different regulating factors for rangeland grasshoppers. |
RELATED WEBPAGES |
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Grasshoppers: Their Biology, Identification and Management
(Comprehensive web site)
Homing In on Hopper Hordes (Agricultural Research Magazine)
Grasshopper
Management CD Request Form
More Grass, Fewer
Grasshoppers! (.PDF)
U.S.
Rangeland Grasshopper Collection
Grasshopper Research at NPARL
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PUBLICATIONS
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Branson, D. H. 2003. Effects of a
parasite mite on life-history variation in two grasshopper species.
Evolutionary Ecology Research 5: 397–409.
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Branson, D. H. 2003. Reproduction and
survival in Melanoplus sanguinipes (Orthoptera: Acrididae) in
response to resource availability and population density: the role
of exploitative competition. The Canadian Entomologist 135: 415-426.
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Branson, D. H. and Redlin, B. (eds.).
2004. Grasshoppers: Their Biology, Identification and Management.
2nd Edition. CD-ROM. US Department of Agriculture, Agricultural
Research Service.
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Branson, D. H. 2004. Relative
importance of nymphal and adult resource availability on
reproductive allocation in Melanoplus sanguinipes (Orthoptera:
Acrididae). Journal of Orthoptera Research 13: 239-245.
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Branson, D. H. 2005. Effects of fire
on grasshopper assemblages in a northern mixed-grass prairie.
Environmental Entomology. In press.
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Branson, D. H. 2005. Direct and
indirect effects of avian predation on grasshopper communities in
northern mixed-grass prairie. Environmental Entomology. In press.
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Branson, D. H. 2005. Life-history
responses of Ageneotettix deorum (Orthoptera: Acrididae) to host
plant availability and population density. Journal of the Kansas
Entomological Society. In press.
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USDA-ARS-NPARL
P.O. Box 463 Sidney, MT 59270 PH: 406.433.2020 FAX: 406.433.5038
For accessibility
questions or other concerns, please e-mail: webmaster[at]sidney.ars.usda.gov
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