The latitudinal variation in spread F, though based only on two-station data sets in this study, looks compatible with the latitude variation of ion density fluctuations observed by the AE-E satellite.
In the present work a spatiotemporal model, based on climatic forecast using the concept of growing degree days [ 16], retrospectively predicts a latitudinal and altitudinal spreading of the potential transmission area of Dirofilaria, mainly in the Russian Federation and Ukraine, near the boundaries where temperatures are close to the threshold for extrinsic incubation of parasite larvae.
Longitudinal and latitudinal historical patterns of spread were analyzed with linear regression models.
We developed a criterion for choosing which climatic station better represented each locality using data from 42 climatic stations spread over a latitudinal gradient of more than 2800 km.
The peculiar northern distribution of haplotype B of nad7 intron 1 indicates that Scots pine has likely survived in a refuge distinct from those usually recognized in the southern peninsulas of Europe, perhaps under the form of scattered glacial populations spread over sizeable latitudinal areas reaching European mid-latitudes not far from the ice front.
The spread did not follow latitudinal isolines as would be expected under a scenario of early planting, even though an analysis of planting date has not been conducted.
Sampling was spread across the species' known latitudinal, longitudinal and altitudinal range (Fig. 1).
Recently, Bagiya et al. (2013) have reported that h'F at 19 30 LT in the Indian equatorial region is well correlated with the altitudinal extension of spread F, which corresponds to the latitudinal extension of plasma bubbles.
However, Wells (1965) [48] suggested that high water temperatures might limit L. littorea 's spread in the Atlantic, noting that its southern latitudinal limit on the East Coast and European shores occurred where the summer monthly mean water temperature reaches at least 21°C.
Thereafter this species showed a rapid spread and adaptation to the new colonized environment in form of latitudinal clines for chromosomal polymorphism and body size that paralleled the Paleartic clines [ 17, 18, 21].
