AS A boy, Antoine Hubert used to catch butterflies. These days, the agro-engineer has eyes only for meal worms. In a demonstration factory near Dole in eastern France, he shows how trayfuls of plump, half-grown worms are fed, left to grow in a darkened dormitory, and then—after two months—slaughtered and cleaned with a blast of steam.

AS A boy, Antoine Hubert used to catch butterflies. These days, the agro-engineer has eyes only for meal worms. In a demonstration factory near Dole in eastern France, he shows how trayfuls of plump, half-grown worms are fed, left to grow in a darkened dormitory, and then—after two months—slaughtered and cleaned with a blast of steam.