I'm Forever Blowing Bubbles
Explored July 21, 2020.
Probably the most amazing thing I have ever seen on the macro scale. I was set up with my macro lens and Raynox DCR-250 in my greenhouse, focused on a chili pepper flower that seemed to be preferred by hoverflies, when a different species of fly landed on a petal. As I watched, it blew huge bubbles of crystal clear liquid out of its mouth, held it for a few seconds before reabsorbing it - simultaneously it ejected fluid from its back end! Then it blew another bubble and the process repeated itself several times. The fly held the bubble long enough to allow a 12-shot focus stack - the detail inside the clear bubble is good enough to show other plants in the greenhouse and even details of the fence outside.
This behaviour has a variety of explanations, one being that it is associated in some way with digestion, which may account for the ejection of fluid out of the end of the fly. But the explanation that seems to be the best concerns thermoregulation - water evaporating from the surface of the bubble has a cooling effect, much like the effect of sweat on our skin. When the fly reabsorbs the bubble it helps to cool the fly down, likely a useful behaviour inside a warm greenhouse.
Oddly enough, having never seen this before, I noticed it again a few days later. This time the fly was resting on the glass outside the conservatory, blowing/reabsorbing bubbles on a cool day! At least my husband got the chance to observe the bubble blowing for himself.
I'm Forever Blowing Bubbles
Explored July 21, 2020.
Probably the most amazing thing I have ever seen on the macro scale. I was set up with my macro lens and Raynox DCR-250 in my greenhouse, focused on a chili pepper flower that seemed to be preferred by hoverflies, when a different species of fly landed on a petal. As I watched, it blew huge bubbles of crystal clear liquid out of its mouth, held it for a few seconds before reabsorbing it - simultaneously it ejected fluid from its back end! Then it blew another bubble and the process repeated itself several times. The fly held the bubble long enough to allow a 12-shot focus stack - the detail inside the clear bubble is good enough to show other plants in the greenhouse and even details of the fence outside.
This behaviour has a variety of explanations, one being that it is associated in some way with digestion, which may account for the ejection of fluid out of the end of the fly. But the explanation that seems to be the best concerns thermoregulation - water evaporating from the surface of the bubble has a cooling effect, much like the effect of sweat on our skin. When the fly reabsorbs the bubble it helps to cool the fly down, likely a useful behaviour inside a warm greenhouse.
Oddly enough, having never seen this before, I noticed it again a few days later. This time the fly was resting on the glass outside the conservatory, blowing/reabsorbing bubbles on a cool day! At least my husband got the chance to observe the bubble blowing for himself.