Temperature-Based Phenology Modeling and GIS-Based Risk Mapping 425
to extend its geographic distribution and spread,
especially at higher latitudes and altitudes due to
future climate change (Fig. 5b).
Generation Index
Average numbers of generations that can theoreti-
cally be produced per year by P. solenopsis under
current temperature conditions are visualized
in Fig. 6a. According to the model predictions,
under current climate conditions P. solenopsis
can produce maximum of 10–11 generations per
year. The regions included West- and South-east
coasts of India. Under future climate scenario of
the year 2050, a significant increase in the num-
ber of P. solenopsis generations with a maximum
increase of 2–3 generations is predicted for India,
particularly in the regions of Gangetic plains,
Western Deserts, Deccan plateau, and Eastern
Ghats where warmer conditions prevail (Fig. 6b).
Damage Potential
AI explains the temperature-dependent finite rate
of population increase within a year. Every in-
crease of the index by a value of 1 indicates a ten-
fold increase of the pest population. Under pres-
ent climatic conditions, Westerns semiarid re-
gion, Deccan plateau and Eastern Ghats of India
were predicted optimal for P. solenopsis activity
(Fig. 7a). Similarly, under climate change sce-
nario drastic change in P. solenopsis population
growth and abundance is predicted throughout
the country, barring Northern and North-Eastern
Himalayas where low temperatures limit the pest
survival (Fig. 7b).Fig. 3 Temperature-dependent oviposition curve (sec-
ond-order polynomial regression model)Fig. 2 Temperature-dependent survival rates (1/day) for adults of P. solenopsis: female (a) and male (b). Fitted curves,
Sharpe-DeMichele model. Bars represent standard deviation of the mean