Moth migration
This is a subject that has fascinated me since the 1980's. Some work I was involved with showed that some common pest species (Mythimna (Pseudaletia) unipuncta & Peridroma saucia) could not survive Canadian prairie winters. It was proposed that the moths migrated in some way from the south - US and Mexico. (https://www.cambridge.org/core/journals/canadian-entomologist/article/abs/cold-tolerance-of-pseudaletia-unipuncta-and-peridroma-saucia-lepidoptera-noctuidae1/0503E9AF109FE85AF562FA4FE7516D4C (Paywall = P)). It was unsure at the time whether it was a random migration in that the moths got up into the atmosphere and were blown by chance to the north. The inability to survive northern winter conditions Quebec (https://www.cambridge.org/core/journals/canadian-entomologist/article/abs/overwintering-potential-of-true-armyworm-pseudaletia-unipuncta-lepidoptera-noctuidae-populations-in-quebec1/AE26822F389B0D7B6E327CA8E6182F12 (p)).
Studies seem to show that M. unipuncta not only migrate north, but also south in the Canadian autumn (https://ir.lib.uwo.ca/cgi/viewcontent.cgi?article=7218&context=etd). Later, it was proposed that the migration was a reaction to daylength and temperature - https://link.springer.com/article/10.1017/S1742758400022657 (P).
It appears as if a number of moth species undertake this migration every spring and fall. Not only that, but moths migrate into mountains, and then back to the lowlands (https://www.researchgate.net/profile/John-Brown-13/publication/274221265_Concentrations_of_Lowland_Sphingid_and_Noctuid_Moths_at_High_Mountain_Passes_in_Eastern_Mexico/links/5d3302d7299bf1995b398ddf/Concentrations-of-Lowland-Sphingid-and-Noctuid-Moths-at-High-Mountain-Passes-in-Eastern-Mexico.pdf). It also appears that the abundance of moths in mountains seems to help sustain Grizzly Bear populations (http://scholarworks.unr.edu:8080/bitstream/handle/11714/4220/Robison_unr_0139D_10331.pdf?sequence=1&isAllowed=y)!
As I said, this is fascinating to me.