Both the eggs and the adults of Water Boatmen and Backswimmers are edible, and consumed in several parts of the world. The most notable example of this is in Mexico, where the eggs were “farmed” when bundles of straw were laid in the lake (the famous one at Mexico City, which in the last half-century or so has gotten badly polluted, such that these insects aren’t found in great numbers any more — so I’ve read). Back in the Aztec days, the eggs were a food reserved for royalty.

Dave
SmallStock Food Strategies
http://www.smallstockfoods.com