It’s not every day that you hear about spy missions that involve
a lack of sex, but clearly parasitic wasps don’t pay much
attention to Hollywood clichés. These insects merge the
thriller, science-fiction and horror genres, They lay their eggs
inside other animals, turning them into slaves and living
larders that are destined to be eaten inside-out by the
developing grubs. To find their victims, they perform feats of
espionage worthy of any secret agent, tapping into their mark’s
communication lines, tailing them back to their homes and
infiltrating their families. Two species of parasitoid wasp –
Trichogramma brassicae and Trichogramma evanescens – are
particularly skilled at chemical espionage. They’ve learned to
home in on sexual chemicals used by male cabbage white
butterflies. After sex, a male coats the female with anti-
aphrodisiac that turns off other suitors and protects the male’s
sexual investment. These chemicals are signals from one male to
another that say, “Buzz off, she’s taken.” But the wasps