I am not up on Lepidopteras. Last week I was at work mowing at various sites, and when we got to a site, I looked down at my mower and there was a caterpiller on it that I didn’t know what it was (later ID’d as Ctenucha virginica), I was at a bit of a loss as to what to put it on and just picked a plant. Is there a plant that that can be a catch all for future reference, or would I need to know the species?
There is no plant which is a host of all caterpillars, so normally you would need to know species to identify suitable hosts.
That is a good question to ask. When I find a caterpillar in a dangerous place in the open and I don’t know the host plant. I put it back on any nearby plant with sufficient leaves to hide it from the sun and birds. I assume that the caterpillar’s efficient locomotion will get it back to a food plant in short order. I just googled C. virginica. It eats grasses including sedges.
@botanicaltreasures so putting it on the ground at the base of the plant might be the best option?
I just put them on the ground under plants, they wil find the host later.
Often when caterpillars are wondering around it means they’re finished eating and are trying to get away from its host plant to form a pupa. I’m guessing it’s because predators and parasites would target the host plant.
I’d say so.
@upupa-epops. I think that begs the question; what kind of structure do most caterpillars prefer for pupating?
It is intriguing to consider why the caterpillar was found where it was. Was it foraging or looking for sheltered real estate to pupate on? The size of the caterpillar would give a clue as to whether it was an early or late stage instar. If it were ready to pupate than it might not even choose a plant, but prefer a hard surface.
@botanicaltreasures, (for us amateurs) how can we tell the difference between young, hungry, foraging caterpillars and old, fat, and sleepy caterpillars just looking for somewhere to do their power ranger thing?
@zorrosidekick Prepupal larvae refuse to eat. Note that some starving larvae which have fallen out of their tree may also refuse to eat until left undisturbed for a few hours, although others will eagerly accept hosts whenever they make contact. Many butterflies have naked pupae which hang upside down from hard inanimate objects, but some do produce cocoons; I reared a hesperiid from a silk bag once, it was tied to a concave grass leaf, probably the host. Some moth species (notably the common lab hornworm Manduca sexta) do not pupate in the open at all and do so underground. Since pupation preferences vary by species I also suggest researching species to find out; unfortunately some of the micromoths are very poorly studied and essentially nothing is known about them, so for these I suggest a mix of different potential pupation sites.
I’m an amateur also, but one of my favorite things to do is look at caterpillars to check them for tachinid eggs or wasp cocoons. I choose a moth or butterfly family or genus and then filter for life stage “larva” . It is fascinating to see how different an early instar (just hatched) can look versus an old instar in the same species. Also sometimes the same caterpillar has several color choices.