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.