Bulbophyllum phalaenopsis, orchid species named after another orchid genus. Gastrodia bambu was named after the Indonesian word for, well, bamboo, because it grows near patches of bamboo.
And one theory (for which I cannot find where I read it) says that the genus Aa was named after the first and last letters of Altenseinia from which it was split. But to me this seems like a post hoc justification.
There are also some orchids with the epithet graminea or gramineum (Which I believe literally means “grass”). I can imagine whoever’ described them going “umm. this kinda just looks like grass.”
And all those species named after people are technically named after (individuals of) another species too
Anacampsis rhoifructella (named for Rhus fruits, but actually feeds on Viburnum fruits), Sphinx sequoiae (named for Sequoia but actually feeds on junipers), and Acronicta lobeliae (named for Lobelia but actually feeds on oaks) are three more that come to mind with misleading host-based names.
And then there are species that were named for a non-native host, like Liriomyza arctii, named for Arctium (burdock), which is what it’s most often found feeding on now. But the insect is native only to North America, where Arctium is not native, so its original host must have been something else. Same deal with the Ailanthus Webworm, whose native range is entirely devoid of any native Ailanthus.
Plus there are plenty named for hosts whose names have changed due to taxonomy updates- Erysiphe sedi is named for the host Sedum, but the hosts it’s most associated with have been moved out of Sedum and into the genus Hylotelephium. Cycloplasis panicifoliella is named for the grass genus Panicum, but its host species is currently in Dicanthelium, not Panicum. Eupithecia cimicifugata is named for the plant genus Cimicifuga, but Cimicifuga has now been lumped into Actaea.
These are fun to brainstorm; I’m sure there are loads more…
Some names are just ridiculous. Like Erica ericoides - the Heath that resembles a Heath. https://www.inaturalist.org/taxa/584815-Erica-ericoides
(It was previously in a related genus, Blaeria ericoides, that got sunk into Erica, and so the species name transferred.)
