Courtship of Poecilobothrus nobilitatus (Dolichopodidae)The Dolichopodid fly Poecilobothrus nobilitatus is a common species which can be abundant in the right conditions. It likes the shallow, muddy edges of pools and streams and even muddy puddles in dappled shade. Dolichopodids (long legged flies) have extravagant external male genitalia, they are typically colourful with metallic green and blue colours and iridescent eyes and the legs of males are often ornamented. In this particular species, the males, which are about 5-6 mm long, have the wings blackened over the outer half and milky white tips.
|Poecilobothrus nobilitatus male|
|Poecilobothrus nobilitatus female|
There is a small pond in my garden in the shade of a Scot's Pine tree. This obviously provides the right conditions for P. nobilitatus and large numbers are present at the moment - and courting furiously.
|Poecilobothrus on the pond - these are mostly females|
Photos were taken using a 100mm macro lens at around f16. The main illumination was from Canon MT-24 dual flash with a Yongnuo 560 III providing background illumination. A Yongnuo RF605C radio unit was used to trigger the background flash. The Canon 80D camera was set in manual mode and the flash power set as low as possible - around 1/8 or 1/16 power. This reduces the flash duration allowing for high speed imaging. The maximum flash sync speed for this camera is 1/250th sec, so the shutter speed was set to 1/250 or 1/200th. At 100 ISO, f16 and 1/250 sec, the available light level would lead to underexposure of about 4-5 stops, so the exposure is totally due to the flash, therefore the camera's shutter speed is irrelevant (providing the shutter is fully open when the flash fires).
|Male (right) approaching a female (left) wing waving|
|Male wing waving|
|Male leaping over a female|