PARASITIC wasps siphon off antifreeze from their fly hosts to protect them
from chilly winters—a discovery which could improve biological control of
pest flies.
Nasonia vitripennis wasps deposit their eggs in puparia, the
cocoon-like casings of developing flies. When the wasps hatch they feed on the
fly pupae. To survive the winter cold, both flies and wasps go into
diapause—a form of hibernation in which they accumulate antifreeze
compounds.
But the wasps don’t go into diapause until up to two months after the flies.
To try to explain this, David Rivers of Loyola College in Maryland and his…
