PhD Research Student
BSc (Hons) Zoology, University of Edinburgh (1999-2003)
Start Date: 1st October 2007
3A135, Cottrell Building
Biological & Environmental Sciences
tel: +44 1786
The role of inbreeding and parasites in driving declines of bumblebees
Funded by the Natural Environment Research Council
Several bumblebee species have suffered dramatic declines in recent years, predominantly as a result of changes in farming practises. As a result, populations of the rarer species have become isolated and recent studies have demonstrated these populations are suffering from inbreeding. The impact of inbreeding is exacerbated in bumblebees, as their single-locus complementary sex determination system results in the production of sterile or inviable diploid males.
Bombus muscorum (left); a rare species that is suffering from a loss of genetic diversity on Hebridean islands (right), where populations are isolated.
Inbreeding and loss of genetic diversity are significant threats to small, isolated populations. One mechanism via which genetically impoverished populations may become extinct is through decreased immune competence and higher susceptibility to parasites. However, the relationship between inbreeding and parasite resistance in invertebrates is unclear.
This project aims to determine whether the genetic diversity of wild bumblebee populations affects individual immune responses and susceptibility to parasites.
This will be done by measuring immunocompetence and screening parasite prevalence across host species and populations varying in genetic diversity. Bumblebee specimens collected from populations with a known genetic diversity will be dissected and examined for the presence of the nematode, Sphaerularia bombi, the tracheal mite, Locustacarus buchneri, the protozoa, Apicystis bombi and hymenopteran or dipteran parasitoid larvae. The presence of the protozoan parasites, Nosema bombi and Crithidia bombi will be detected using diagnostic PCR primers.
I have been involved in a number of projects in Eastern and Southern Africa and I am fascinated by the research opportunities provided by the varied environments and abundant wildlife in these areas, as well as the challenges associated with conserving them. The projects included biodiversity research and awareness in the Eastern Arc mountains in Tanzania, managing large game in South African reserves and investigating the effects of poaching on large mammal populations in Malawi. I have also worked on a study of sylvatic plague in prairie dogs and the associated conservation of the black footed ferret in the US. My interest in Hymenoptera was sparked as an undergraduate, when I was involved in studying kin recognition in a parasitoid wasp, N. vitripennis.
Publications and previous research projects
Whitehorn, P.R., Tinsley, M.C. & Goulson, D. (2009). Kin recognition and inbreeding reluctance in bumblebees. Apidologie 40(6): 627-633.
Whitehorn, P. (2005) Fire effects on the grasslands and ungulate community of Mankwe Reserve, South Africa. Unpublished MSc dissertation.
Shuker, D.M., Reese, S.E., Whitehorn, P.R. & West, S.A. (2004) Sib-mating does not lead to facultative sex ratio adjustment in the parasitoid wasp, Nasonia vitripennis. Evolutionary Ecology Research 6: 473-480.