The life history of Mesovelia mulsanti was studied during 1983-1986. This species was apparently trivoltine with a partial 4th generation at the end of the year. It overwintered as eggs. First ins tars appeared in mid-April followed by marked overlapping of the subsequent instars and generations. The first adults appeared in early May. No active individuals were found after November.
McPherson, J. E.
"Life History of Mesovelia Mulsanti (Hemiptera: Mesoveliidae) in Southern Illinois,"
The Great Lakes Entomologist, vol 21
Available at: https://scholar.valpo.edu/tgle/vol21/iss1/5