Wednesday, 3 August 2016

Hoverfly round-up so far 2016

With all the poor weather and rain, I decided to plot my hoverfly data to see if anything stood out. It seems that even though we are having a wet summer Hoverfly numbers are up in species recorded and numbers counted. The 2016 records compared to 2015 show that the number of species seen is up for late spring and summer, but down for early spring. This has to be weather related as the cold late spring hit numbers badly. Summer numbers are up, so hoverflies are not really bothered by periods of wet weather and emerge in huge numbers during dry periods for a few days as witnessed lately. I have since learned that flowers do not pollinate as much during long periods of warm fine weather and shut down the pollinating process during droughts to conserve energy until more water is available, thus not attracting as many hoverflies. Luckily there are many areas where the ground remains boggy during droughts like Garnwen and Lletty Brongu and it is not surprising these sites hold the highest numbers in species and totals during any weather conditions. The only blip to this theory is June where totals were higher in 2015 than 2016 and I think this is down to the fact that there hasn't been a large emergence of "Syrphus" in 2016 compared to 2015 mirroring the fact that Bramble [Syrphus preferred feeding plant] has had a bad year due to  the flowers being destroyed by flash storms.

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