Your worst enemies can really get under your skin. Insects known as parasitoids do just that, getting into other insects’ bodies and eating their hosts alive from the inside out.

More than 100,000 described parasitoid species of wasps, flies and other insects lurk the globe, hoping to turn nearly every type of insect’s life into a horror show.

The following parasitoids master the horrifying art of living inside an all-you-can-eat buffet.

1. Aphidiinae
BHR-parasitoid-illo-2Aphidiinae wasps are aphid specialists. These tiny terrors find unsuspecting aphids and jam their waspy eggs directly into the aphids’ abdomens with needle-like egg-laying devices. Our poor aphids die slowly as wasp larva slurp their nutritious aphid guts. Meanwhile, the aphids’ outsides turn into a papery, brown protective husk, from which Aphidiinae burst triumphantly as adults.

Don’t get too comfy inside that aphid husk, Aphidiinae!

2. Asaphes vulgaris

Hyperparasitoids, like the even smaller wasp Asaphes vulgaris, attack parasitoid wasps already infecting hosts. Hyperparasitoids of Aphidiinae, for example, will seek out parasitized aphids. The hyperparasitoid inserts an egg into the first parasitoid, and after its own gobblefest, the new larvae pupates before chewing its way out of the aphid, like the tiniest doll in a horrific babushka.

Some parasitoids don’t have an only child complex.

3. Copidasoma


Copidasoma takes a “DIY, babies!” approach to child rearing by depositing a few eggs into moth eggs. The moth caterpillars hatch, unaware that they’re stuffed with flesh eating aliens. While the young caterpillars grow up, the wasp eggs rapidly divide, and the original few become up to 2000 eggs, a trait known as polyembryony. When the caterpillar reaches a certain age, those eggs hatch and, you guessed it, the thousands of maggot-like wasp larvae begin eating the poor caterpillar alive from the inside out! Feeling nervous, caterpillar? That might not be butterflies in your stomach, but wasps!


Check our facts!

STONER, A., AND WEEKS, R. E. 1976. Copidosoma truncatellum, a polyembryonic parasite of Trichoplusia ni age of host eggs parasitized, searching, fecundity, and effectiveness. Environ. Entomol. 5: 323-328.
Biology and host selection behaviour of the aphid hyperparasitoid Alloxysta victrix in association with the primary parasitoid Aphidius colemani and the host aphid Myzus persicae
Grasswitz, T ; Reese, B Grasswitz, T. BioControl, 1998, Vol.43(3), pp.261-271
Parasitoids: Behavioral and Evolutionary Ecology
H.C.J. Godfrey (1994)


Written by Chris Hedstrom.  Chris is a entomologist in Corvallis, OR studying biological control for the Oregon Department of Agriculture. He’s also an illustrator and photographer. Check out new drawings, photos and writing as they appear at or

Illustrated by Christine Fleming, Buzz Hoot Roar’s Artist in Residence. Follow Christine at @might_could and check out more of her work here.