Day fly and Shadfly

Shadfly and day fly are semantically related. In some cases you can use "Shadfly" instead a noun phrase "Day fly".

Shadfly noun - Slender insect with delicate membranous wings having an aquatic larval stage and terrestrial adult stage usually lasting less than two days.

Day fly and shadfly are semantically related. Sometimes you can replace phrase "Day fly" with "Shadfly", this terms are similar.