Mosquitoes larvae (culicidae) feeding on rotten vegetal material in the still water of a canal.There is some pupae between them, although they don't feed in this stage of developpment they still able to swim.Donoratico, Livorno, Italy
This pretty little syrphid fly, Chalcosyrphus piger, was displaying and/or basking from the railing of my deck. These flies are said to be "hilltoppers", that is, they gather at high places for mating, with males tending to stake out territories. These flies are all dark except for the bright red abdomen and are said to be Batesian mimics of spider wasps with this pattern, esp. genus Astata. (See adjacent lateral view for comments on ID.) Length about 10 mm.