I recently wrote a post about guessing the species. It’s not always trivial to get clarification on the species of an individual. Especially in case of young caterpillars there might be only one safe way to determine the species: Grab some individuals in a jar and raise them!
So I did. I went back to the spot where I found a rather large colony of what I believed was caterpillars of the Map (Araschnia levana). Even though I found caterpillars of the Map 2 meters away from the colony they did not 100% look identical. To get peace of mind I placed 5 caterpillars in a box at home, fed them and started to wait.
For the comparison I had the caterpillars of A. levana, which I collected earlier, in a separate box. These were identified by observing the horns on the head of the caterpillars. This unique characteristic leaves no doubt that the individuals are from the Map.
After about 7-10 days the unidentified specimen started to reach a size where details can be easier observed. This also means the species can finally be determined. And my guess was wrong, but my doubt was confirmed. The caterpillars indeed are from the European Peacock (Inachis io), not from the Map.
Bottom line, I must admit this small experiment has been fun. Furthermore, the European Peacock is one of my season targets I wanted to raise this summer. That said, one more target has been nailed rather through coincidence. But I’ll take it.