Robert John Brightwell

Ph.D. Candidate

Main Advisor:  Dr. Jules Silverman

3321 Gardner Hall
Raleigh, NC 27695-7613
Phone: 919-515-3784
Cell: 919-302-3540
Fax: 919-515-7746
Email:rjbrigh2@ncsu.edu

 

 

 

EDUCATION

B.Sc. with 1st class honours  
Victoria University of Wellington (2002)
Ecology and Biodiversity

 

 

RESEARCH

My main interest is in understanding the mechanisms that allow a species to successfully establish and then dominate a new environment. The model organism used is the Argentine ant, Linepithema humile, a tramp ant species that is well established in North Carolina and across much of the world. Most distribution models would predict North Carolina’s winters to be too cold for Argentine ant nests to survive outside human structures, yet they readily do. It seems that the Argentine ant finds a foraging refuge on pine trees in the cold winter months. The bark of the pine tree absorbs the sun's heat and can maintain temperatures well above the ambient air temperature and within the optimum foraging temperature range of the Argentine ant. In North Carolina, at least, there are coccids and aphids that feed on the pine throughout the winter and the Argentine ant forages on this honeydew source throughout the North Carolina winter.

The Argentine ant readily forms facultative mutualisms with honeydew producing Hemiptera. This ant forms a mutualism with the native terrapin scale, Mesolecanium nigrofasciatum, on red maples in a local industrial park and I am exploring the benefits and costs for each organism. It appears that the terrapin scale requires the presence of the Argentine ant to escape its myriad predators and parasitoids and their populations crash when Argentine ants are denied access. Local numbers of Argentine ant foragers do not drop when denied access to the terrapin scale although Argentine ant nests move away. This mutualism between the Argentine ant and terrapin scale inflicted a net cost to the fitness of the red maple host with lower seed mass seen on those red maples with canopy foraging Argentine ants. I am also investigating whether restricting this honeydew resource will augment traditional insecticide control of the Argentine ant. It appears that bait consumption is lower in areas where access to honeydew is curtailed; probably due to the increased distance to the relocated Argentine ant nests.

It is interesting that local native ant species do not form mutualisms with this native coccid species. I am interested if the successful establishment of an invasive ant propagule is dependant on the availability of an under-utilized resource such as honeydew from native hemiptera.

 

 

PUBLICATIONS

Brightwell, R.J. and Silverman, J. In review. Invasive Argentine ant reduces fitness of a common trees species via trophobiosis. Ecology,

Silverman, J. and Brightwell, R.J. (2008). The Argentine ant: challenges in managing an invasive unicolonial pest. Annual Review of Entomology, 53: 231-52.

Brightwell, R.J. and Silverman, J. (2007). Argentine ant foraging activity and interspecific competition in complete vs. queenless and broodless colonies. Insectes Sociaux, 54: 329-333.

Bell, V.A., Brightwell, R.J., Lester, P.J. (2006). Increasing vineyard floral resources may not enhance localised biological control of the leafroller Epiphyas postvittana (Lepidoptera: Tortricidae) by Dolichogenidea spp. (Hymenoptera: Braconidae) parasitoids. Biocontrol Science and Technology, 16: 1031-1042.

 

LINKS

Full Curriculum Vitae

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