Scientists have found that an aquatic insect known as a backswimmer, which is similar a water boatman, releases a "scent" that scares off mosquitoes - although it cannot be picked up by the human nose.    From Wordnik.com.  [Telegraph.co.uk: news, business, sport, the Daily Telegraph newspaper, Sunday Telegraph] Reference

While many say that water boatmen do not bite and are often confused with the backswimmer, I am sure that the insects in the pool were water boatmen, so I would urge some care in handling them if you come across them and want to take a closer look.    From Wordnik.com.  [Sierra Sun - Top Stories] Reference

Yeah, I broke the ice for the one backswimmer.    From Wordnik.com.  [grouse Diary Entry] Reference