Data from: Projecting pest population dynamics under global warming: the combined effect of inter- and intra-annual variations

The typical short generation length of insects makes their population
dynamics highly sensitive not only to mean annual temperatures but also to
their intra-annual variations. To consider the combined effect of both
thermal factors under global warming, we propose a modeling framework that
links general circulation models (GCMs) with a stochastic weather
generator and population dynamics models to predict species population
responses to inter- and intra-annual temperature changes. This framework
was utilized to explore future changes in populations of Bemisia tabaci,
an invasive insect pest-species that affects multiple agricultural systems
in the Mediterranean region. We considered three locations representing
different pest status and climatic conditions: Montpellier (France),
Seville (Spain), and Beit-Jamal (Israel). We produced ensembles of local
daily temperature realizations representing current and future (mid-21st
century) climatic conditions under two emission scenarios for the three
locations. Our simulations predicted a significant increase in the average
number of annual generations and in population size, and a significant
lengthening of the growing season in all three locations. A negative
effect was found only in Seville for the summer season, where future
temperatures lead to a reduction in population size. High variability in
population size was observed between years with similar annual mean
temperatures, suggesting a strong effect of intra-annual temperature
variation. Critical periods were from late spring to late summer in
Montpellier and from late winter to early summer in Seville and
Beit-Jamal. Although our analysis suggested that earlier seasonal activity
does not necessarily lead to increased populations load unless an
additional generation is produced, it is highly likely that the insect
will become a significant pest of open-fields at Mediterranean latitudes
above 40° during the next 50 years. Our simulations also implied that
current predictions based on mean temperature anomalies are relatively
conservative and it is better to apply stochastic tools to resolve complex
responses to climate change while taking natural variability into account.
In summary, we propose a modeling framework capable of determining
distinct intra-annual temperature patterns leading to large or small
population sizes, for pest risk assessment and management planning of both
natural and agricultural ecosystems.