The search for caterpillars you want to raise, the so called keepers, sometimes also reveals others. Not every caterpillar is a keeper. However, it is always fun to spot any individuals, especially if you can beat their disguise.
The photo above shows the caterpillar of a moth, perhaps a Silver Y (Autographa gamma), which I could not identify. Even though I did not proceed with this caterpillar and take it home, it was still worth a couple shots. Fair enough to say that the more you are searching for wanted species, the more you’ll also spot others by coincidence.
Keepers are definitely those species defined as the season targets. Nevertheless, a season cannot always be predicted, and a caterpillar you would have never expected may cross your path on a quest. Eventually, everyone decides on their own which species are attracting them. Someone only raises Old World Swallowtails, others care about moths only.
Every once in a while you might find a caterpillar when you least expect it. Late summer 2013 we found a larva of the Elephant Hawk-moth (Deilephila elpenor). Having no jar with us that day we decided it was not a keeper. Yet again, it was still worth taking some photos and introducing the hornworm to Sienna (see below).
The Buff-tip (Phalera bucephala) caterpillars, found on the search for Privet Hawk-moths, were worth to be taken home for a closer look. I placed them later on a birch next to our house. I must admit I slightly regret that I won’t be able to see them hatch this year.
Did you know…
Caterpillars of some species are specialized on feeding on a single kind of plant only. Such species, like the Small Tortoiseshell, are monophagous. Other species, e.g. the Mourning Cloak, are oligophagous, feeding on a restricted range of plants. If an even broader range of plants is accepted as food, like in case of the Small Emperor Moth, the species is called polyphagous.
Source: Murtosaari (J) & Mäntynen (P), 2013. Perhosten vuosi, Minerva Kustannus Oy, pp. 37