An egg of corn earworm (also called bollworm or tomato fruitworm), Helicoverpa zea, turned blackish because it was parasitized and killed by a Trichogramma sp. wasp. The adjacent egg was not parasitized, as evidenced by its pale color and the ragged hole chewed by an emerging caterpillar.

Egg parasitized by Trichogramma next to hatched egg; . Credit: Jack Kelly Clark
Credit: Jack Kelly Clark