The Clubbed General, Stratiomys chamaeleon Mysteries
Jul 19, 2017 19:01:59 GMT
deliasfanatic and trehopr1 like this
Post by nomad on Jul 19, 2017 19:01:59 GMT
Stratiomys chamaeleon, the Clubbed General is a large and striking yellow and black soldierfly of the family Stratiomyidae.
Today, S. chamaeleon is one of the rarest species of the British Diptera, being found in 7 sites in calcareous spring fed fens. In Britain, this species is classified as endangered and is a Red Data Book species and all of its breeding British populations are thankfully protected in local and National Nature Reserves.
If it were not for S. chamaeleon habit of visiting umbellifers, this species would be very rarely seen. At Cothill Fen NNR in Oxfordshire there are very few nectar sources for this species and it was found in 2014 and in subsequent years that adults were visiting a private rather large disused shallow quarry away from their breeding locality to take nectar at the yellow umbellifer, wild parsnip.
To reach that quarry, S. chamaeleon has to negotiate away from its breeding habitat, over half a kilometer that involves crossing a hedgerow, a large field, another field with garden and house that is edged by plantation of tall trees, perhaps they use the adjacent old track=bridleway to enter the old quarry through the hedgerow and trees.
This leads to many questions!! How did the S. chamaeleon first find the nectar source at this distance? How do different emerging individuals know how to get here? How do they know how to find there way back to their fenland home from the quarry? How do different yearly generations of S. chamaeleon know how to find the same nectar source growing in the quarry? Can individuals detect the smell of the plant at such a distance which we cannot at close quarters? If this is true, then on the day of my visit to the private quarry, when wild parsnip was in very short supply through over-grazing by cattle, the quite strong breeze was blowing from the east, away from the fen, yet inspite of this, a single male S. chamaeleon had arrived here? Why do they not all fly from Cothill Fen to another site to the south, about the same distance where wild parsnip grows in much greater profusion and is next to a smaller fen with a resident population of S. chamaeleon, unless some do? Is this travel for nectar being bred into the Cothill Fen population genes and how?
Answers welcome on a postcard or preferably here !!
As both sexes S. chamaeleon of will travel to find a nectar source away from breeding areas, it has been suggested that this nectar is essential for its breeding success.
A travelling male of S. chamaeleon visiting wild parsnip, Pastinaca sativa at a private disused quarry site, July 2017. Image taken with a Nikon D2400 and a Nikon 105m VR Macro Lens.
Today, S. chamaeleon is one of the rarest species of the British Diptera, being found in 7 sites in calcareous spring fed fens. In Britain, this species is classified as endangered and is a Red Data Book species and all of its breeding British populations are thankfully protected in local and National Nature Reserves.
If it were not for S. chamaeleon habit of visiting umbellifers, this species would be very rarely seen. At Cothill Fen NNR in Oxfordshire there are very few nectar sources for this species and it was found in 2014 and in subsequent years that adults were visiting a private rather large disused shallow quarry away from their breeding locality to take nectar at the yellow umbellifer, wild parsnip.
To reach that quarry, S. chamaeleon has to negotiate away from its breeding habitat, over half a kilometer that involves crossing a hedgerow, a large field, another field with garden and house that is edged by plantation of tall trees, perhaps they use the adjacent old track=bridleway to enter the old quarry through the hedgerow and trees.
This leads to many questions!! How did the S. chamaeleon first find the nectar source at this distance? How do different emerging individuals know how to get here? How do they know how to find there way back to their fenland home from the quarry? How do different yearly generations of S. chamaeleon know how to find the same nectar source growing in the quarry? Can individuals detect the smell of the plant at such a distance which we cannot at close quarters? If this is true, then on the day of my visit to the private quarry, when wild parsnip was in very short supply through over-grazing by cattle, the quite strong breeze was blowing from the east, away from the fen, yet inspite of this, a single male S. chamaeleon had arrived here? Why do they not all fly from Cothill Fen to another site to the south, about the same distance where wild parsnip grows in much greater profusion and is next to a smaller fen with a resident population of S. chamaeleon, unless some do? Is this travel for nectar being bred into the Cothill Fen population genes and how?
Answers welcome on a postcard or preferably here !!
As both sexes S. chamaeleon of will travel to find a nectar source away from breeding areas, it has been suggested that this nectar is essential for its breeding success.
A travelling male of S. chamaeleon visiting wild parsnip, Pastinaca sativa at a private disused quarry site, July 2017. Image taken with a Nikon D2400 and a Nikon 105m VR Macro Lens.