Predicting grape berry moth (Paralobesia viteana) voltinism under high and low greenhouse gas emission scenarios in the 21st century

We use Grape Berry Moth (GBM, Paralobesia viteana) as a model population system to explore changes in biology that may occur with climate projections developed from the average of GFDL, HadCM3 and PCM climate models and the Intergovernmental Panel on Climate Change (IPCC) Special Report on Emission Scenarios. Previous studies have elucidated important aspects of GBM population dynamics including diapause termination, temperature dependent development, and photoperiod induced diapause initiation. Based on historical data from 1960, predicted downscaled climate data until 2099 under both high (A1fi) and low (B1) greenhouse gas emission scenarios of the IPCC, and GBM biology, we ran an individual based Monte Carlo simulation for each year with a population size of 10,000 individuals. Here, we compare mean number of annual generations and emergence times for each generation. The simulations show significant differences in adult emergence time and mean generations between the emission scenarios developing strongly after an approximately 20-30 year lag. Following this lag under low emission conditions, GBM emergence from diapause is slightly earlier, and annual generations increase slightly from ca. 2.8 to 3.1/year. Under high emission condition, on the other hand, by the end of this century GBM display about 3.8 generations/year on average in northern Pennsylvania, about one more than the current 2.8/year, which will cause a significant economic impact to viticulture along the shore of Lake Erie.