- All records for 2014 and 2013 plotted separately
- South of a line created by the northern limits of ST/SU/TQ plotted as separate years 2014 and 2013.
- Midlands - up from the northern limits of ST/SU/TQ to the southern limits of SE/SD plotted as separate years 2014 and 2013.
- North - north of the limits of the southern limits of SE-SD plotted as separate years 2014 and 2013.
- It looks as though there might be as many as four generations in southern England - I expected 3 but there is a bit of a March generation too.
- In 2014 I found no migration peak at the end of July but there is quite a spike by late June - and a pronounced spike in the Midlands.
- The number of generations in the midlands is a bit messy -
probably 3, but I cannot be sure. It begs the question - can one
come up with a series of thermoclines to come up with
differences in phenology?
- The northern population seems to have a distinct single generation.
|Figure 1. Total 2014 records of Episyrphus balteatus against week number.|
|Figure 2. 2014 records of Episyrphus balteatus from southern England.|
|Figure 3. 2014 records of Episyrphus balteatus from the English midlands and Wales.|
|Figure 4. 2014 records of Episyphus balteatus from northern England and Scotland.|
|Figure 5. Total 2013 records of Episyrphus balteatus against week number|
|Figure 6. 2013 Episyrphus balteatus records from southern England|
|Figure 7. 2013 Episyrphus balteatus records from the English Midlands and Wales.|
|Figure 8. 2013 Episyrphus balteatus records from northern England and Scotland|