What it looks like
Leaves are eaten away from the base leaving only bare stalks. A single large caterpillar can strip an entire plant bare.
What other growers did about it
A page like this one can tell you what swallowtail caterpillar on parsley is and what to try. What it cannot tell you is what actually happened to someone who had it on the same plant, at the same point in the season, and what they did next.
Gadenin is a free garden journal built around that. You photograph the plant, tag what you are seeing, and the entries line up by date for each plant you grow.
- Tag the problem and the app tells you how many other growers have logged the same thing on the same plant.
- Growers who make their records public can be followed, so you can read what they did and how it turned out.
- Next season your own entries come back at the same point in the year, so you check the plant before it starts.
Free on iPhone. Recording, tagging and reading public records cost nothing.
About this pest or disease
The general description, causes, and the full list of affected plants are on the pest and disease page. Swallowtail Caterpillar