BARCODE-FACILITATED INVENTORIES ELUCIDATE THE INFLUENCE OF A NATIVE PEST OUTBREAK ON THE MOTH DIVERSITY OF A PONDEROSA PINE FOREST SYSTEM

The recent outbreak of mountain pine beetle and related bark beetles (Dendroctonus spp.) in Western Canada is the most extensive and severe epidemic on record. The consequences of the death of most mature overstory pine trees have been well-studied for birds and other vertebrates intricately tied to the resource pulse, but very little has been done to determine what effect the severe change in habitat is having on comparatively neutral residents.  To this end, we investigated the ecological consequences of the outbreak on resident biotic communities by measuring its effect on a species-rich component, the macro-moths (Lepidoptera). We employed DNA barcoding for rough sorting and species identification of nearly eleven thousand specimens to inventory eight ponderosa pine stands in British Columbia that differed widely in attack by Dendroctonus bark beetles. We determined that rarified species richness for the heavily impacted sites was significantly lower than that of the less impacted sites. Moreover, the linear regression analysis of site attributes and diversity estimates revealed that approximately 85% of the variance in species diversity is explained by ponderosa pine mortality.  Macro-moths have a proven record as indicators of habitat integrity and their perceived depression in species richness may therefore be representative of the larger biotic system.  The ecological consequences of increased pest outbreaks cannot be ignored when other natural and human-induced agents of disturbance are likewise increasing.

deWaard, J.R., Hebert, P.D.N., and Humble, L.M.  (2011).  A comprehensive DNA barcode library for the looper moths (Lepidoptera: Geometridae) of British Columbia, Canada.  PLoS ONE 6: e18290.

deWaard, J.R., Mitchell, A., Keena, M.A., Gopurenko, D., Boykin, L.M., Armstrong, K.F., Pogue, M.G., Lima, J., Floyd, R., Hanner, R.H. and Humble, L.M. 2010. Towards a global barcode library for Lymantria (Lepidoptera: Lymantriinae) tussock moths of biosecurity concern.  PLoS ONE  5: e14280. doi:10.1371/journal.pone.0014280

Update: this is now part of a  collection on the PLOS One site titled “Proceedings of the Third International Barcode of Life Conference, Mexico City“.

deWaard, J.R.,  Humble, L.M., and Schmidt, B.C.S.  2010.  DNA barcoding identifies the first North American records of the Eurasian moth, Eupithecia pusillata (Lepidoptera: Geometridae). Journal of the Entomological Society of BC. In press.

The second is a Canadian Food Inspection Agency publication called ‘Science Scan’ that discusses research articles concerning animal and plant health, particularly those that pertain to emerging pests and pathogens [pdf, pp. 4-5].