During their spring flight season, free-ranging male cecropia moths lived a maximum of 12 days (one of 124 recaptured moths of 387 released moths). The number of survivors declined precipitiously after day five; five to seven days is probably the usual life span. The recaptured moths did not have different initial weights than those that were not recaptured. The larger the moth the more absolute weight it lost and the faster it lost weight during the first few days. A moth lost about 20% of its weight during the first night of flight and accumulated about a 40% weight loss during the remainder of its life.
Waldbauer, G. P.; Sternburg, J. G.; and Janzen, D. H.
"Longevity and Weight Loss of Free-flying Male Cecropia Moths, Hyalophora Cecropia (Lepidoptera: Saturniidae),"
The Great Lakes Entomologist: Vol. 18
, Article 1.
Available at: http://scholar.valpo.edu/tgle/vol18/iss4/1