Aphid Mummies

There's been a surge in aphid numbers in my garden lately, but here's some evidence that predators are active too:

These swollen-up aphids have had an egg laid in them by a predatory wasp, Aphidius rosae. The wasp was introduced to Australia as a biological control agent for the rose aphid in the 1990s. Its larvae eat the aphids from the inside, then pupate inside the "aphid mummy" - the swollen empty shell of the aphid. When they are ready, they leave by cutting a round hole in the abdomen. No holes yet, so the larvae must still be inside.