With no explanation, label text_A→text_B with either "DON'T KNOW", "NO" or "YES".
text_A: "Drosophila" species vary widely in their reproductive capacity. Those such as "D. melanogaster" that breed in large, relatively rare resources have ovaries that mature 10–20 eggs at a time, so that they can be laid together on one site. Others that breed in more-abundant but less nutritious substrates, such as leaves, may only lay one egg per day. The eggs have one or more respiratory filaments near the anterior end; the tips of these extend above the surface and allow oxygen to reach the embryo. Larvae feed not on the vegetable matter itself, but on the yeasts and microorganisms present on the decaying breeding substrate. Development time varies widely between species (between 7 and more than 60 days) and depends on the environmental factors such as temperature, breeding substrate, and crowding.
text_B: Do larvae feed only on yeasts and microorganisms?
YES.