Cut the leaf and put it in a small tank, container.......
Get the water from the com tank. Put a heater and an airstone or sponge filter in and wait for them to hatch.
Meantime,fill a ltr of water (coke bottle, small container...) and put a leaf of lettuce in and put out in the sun.
Get your microworm culture ready.
That way you will have some frys in about 5 days instead of leaving them in the com tank and get nothing in the end.