Got it. Bugs in the airplane's airflow decrease fuel economy, but aren't considered a safety concern.
Safety my first thought, but in respect to the stealth aircraft, and it's pilots. Missions launched from the U.S. to say Iraq, they should accumulate a lot of bugs, - I did check, Hemolymph being a copper-based protein https://en.wikipedia.org/wiki/..., not so stealthy when they arrive at their destination. I know they also fly patterns to avoid areas known to have radar coverage, but those times they are in an area of radar coverage.
"May Berenbaum says pilots have long known insects can fly very high." http://www.npr.org/sections/kr... with the bumblebees as high as 18,000ft, so many that from China to the U.S. "They are likely to be burning a ton of energy to maintain flight." http://www.independent.co.uk/n... (Kool picture of a Bumblebee about to get high).
So maybe it's already been done (finding a way to reduce bug splatter), but would be a security risk if revealed, as anything to do with the Stealth aircraft is.