Parasitic Wasp
A diverse family of very small wasps, most under 1/4 inch long, that lay their eggs inside or on pest insects. The larvae develop inside the host, eventually killing it.
Why you want them
Parasitic wasps are among the most effective biological pest control agents available. They target caterpillar pests such as cabbage loopers and cabbage worms, aphids, and whitefly, laying eggs that hatch into larvae which consume the host from within. They can track down pest species at surprisingly low densities, making them valuable even before outbreaks develop. Adult parasitic wasps are tiny and harmless to humans - they have no meaningful sting.
Helps control
How to attract them
- Dill
- Fennel
- Yarrow
- Sweet alyssum
- Carrot flower
- Phacelia
- Buckwheat
Preferred habitat
Wherever pest insects are present. Adults need nectar and pollen for energy. Overwintering varies by species - some overwinter as larvae inside host pupae, others in sheltered vegetation.
What harms them
Any broad-spectrum insecticide kills parasitic wasps alongside pests. Loss of diverse flowering plants that adults need for food. Pesticide timing during bloom is particularly harmful.
Related pest guides
Garden, by Willowbottom works with nature, not against it. Support your garden allies and they will do most of the hard work for you.