Garden Guests Diary - Blowing Bubbles [11 Jan 08]

Friday, January 11th, 2008 Garden Guests Diary - Blowing Bubbles [11 Jan 08]

I captured this fly blowing bubbles in my garden recently and was fascinated. I couldn’t help but wonder why he was doing it. After a little bit of research on the internet, there doesn’t seem to solid evidence to suggest why. Does anyone have any information on this?

Fly blowing bubble

Some theories:

Functional significance – if the behaviour has any – as yet unknown, but there are some interesting suggestions:

a. Bubble-blowing may play a role in digestion:

i. Concentrating the fluid through evaporation:

ii. Aerating the fluid so that microbial fauna would be affected to the detriment of obligatory;

iii. Heating up the fluid by exposure to sunshine.

b. Bubble-blowing is a symptom of a common fly illness.

c. Bubble blowing is a defensive move. Some insects use regurgitated food as a weapon. They try to spread the sticky, noxious liquid over the attacker.

d. Flies do blow bubbles to clean their mouthparts with this fluid, more or less to flush them, and after they are ready they ingest the fluid again.

e. Flies can use bubbling for cooling of overheated body – thermoregulation.

from: http://www.diptera.info/readarticle.php?article_id=16