Green Caterpillars on Plants: Who Is Eating With You?
Photograph the damaged leaf, answer a few short questions and receive a named diagnosis with a confidence level plus a dated treatment plan.
Diagnose my plant →Holes appear overnight, the culprit does not
You water in the evening and the plant looks fine. By morning the leaf edges are scalloped, whole leaf blades are skeletonised and small dark pellets sit on the pot rim or on the leaves below. The animal itself is nowhere to be seen, because most green caterpillars feed at dusk or hide on the underside of the leaf where their colour matches the vein perfectly.
So you start guessing. Is it a butterfly larva, a moth larva, a sawfly larva that only looks like a caterpillar, or something the plant is doing to itself? Every guess leads to a different answer, and the wrong answer costs you a week of feeding damage while the population doubles.
That guessing game is the real problem. Not the caterpillar itself, but the days you lose between seeing the damage and knowing what you are actually looking at, and knowing whether it is a harmless garden visitor, a pest you can pick off by hand, or a regulated organism that a public authority has to hear about.
Green is not a species
Green is camouflage, not an identity. Cabbage white larvae, looper caterpillars that arch their backs as they walk, box tree moth larvae with their dark head capsules and sawfly larvae with too many prolegs all show up in the same shade of green, on very different host plants, at very different times of year.
The useful clues are not the colour. They are the feeding pattern, the host plant, the position of the droppings, whether webbing is present and how the animal moves when you touch it. Dr. Phyto asks about exactly those things, then names the most likely organism and tells you how confident that identification is instead of presenting it as settled fact.
From photo to a plan with dates on it
After the diagnosis you get a treatment plan with steps in order and a date against each one, because timing decides everything with caterpillars. A mechanical measure taken on the right day beats a chemical measure taken two weeks late, and the plan says which is which.
Where a plant protection product would be the sensible route, the plan explains the category and the conditions, and then points you to the register of products authorised in your own country. Authorisations differ from one member state to the next, so a product cleared in Italy is not automatically legal in Germany. For the concrete product choice, the dose and any label conditions such as waiting periods, check with your agronomist or ask us directly.
What Dr. Phyto will not tell you
It will not promise recovery. If the feeding damage has gone past the point where the plant can rebuild its canopy, the report says so plainly, and it says it early enough that you can decide about the remaining plants around it.
It will not present a diagnosis as certain. Every identification comes with a confidence level, and where the photo does not carry enough information the report asks for a better angle rather than inventing an answer. That is the difference from a general chatbot: the reasoning is anchored in a verified European knowledge base.
When it stops being a garden matter
A small number of leaf feeding species are regulated under Regulation (EU) 2019/2072. If the identification points that way, the report tells you to notify the competent national authority, and it does not soften that duty.
In that case you do not dispose of the affected material yourself, you do not move it and you do not sell it. Local authorities and municipalities use the same route in reverse: a citizen photo becomes an early warning long before an inspector is on site.
Can Dr. Phyto tell a caterpillar apart from a sawfly larva?
Often yes, if the photo shows the body and legs clearly. The report names the most likely group, states the confidence level and lists the features that separated it from the alternatives, so you can check the reasoning yourself.
Which spray should I use against green caterpillars?
We do not name products. Authorisations are national and change over time, so we point you to the register of authorised products for your country and to the label conditions. For the actual choice and dose, speak to your agronomist or ask us directly.
What if my plant is already stripped bare?
Then the report says whether it is realistic that the plant recovers or not. We do not assure a recovery in any case, and where a plant is lost we say so, so you can protect the neighbouring plants instead.
Does this work for professional growers too?
Yes. Vineyards, orchards, greenhouses and market gardens use it for a fast second opinion and for differential diagnosis, and public bodies use it to triage incoming citizen photographs.