This is the kind of stuff you think about when you have your second bout of influenza in a month, even though you got your flu vaccine and took Tamiflu on your first day of symptoms both times. Influenza sucks. Missed six days of work total and felt like dog poo for 14 days altogether. And there are 2 more strains out there. Oh boy. I think I'll hold my breath until spring.
Ok, so here is why I think that we might owe cicadas a great big round of applause for influenza.
First, influenza typically originates in Asia in birds. You know, all those big flocks of ducks and chickens that they insist upon keeping alive until they decide to butcher them and cook them fresh to cut down the chance of getting salmonella and campylobacter. They call some strains "bird flu" but all strains affect birds. Humans are just incidental targets IMHO.
So, if we assume that influenza evolved to control bird populations, the next step is consider where influenza strikes. Winter in the far north and far south. The rainy season around the equator. What is a natural enemy of birds that would exist in one state during cold months and monsoons and a different state during warm months/non monsoons? Flying insects that have a pupal state. I.e. Lepidoptera, moths. They stay underground when it is cold/rainy. They fly when it is nice. Once they get their wings, they have only one thing in mind--procreation. But when they are worms, maybe they can serve another purpose--like getting rid of predators that threaten the breeders.
https://en.wikipedia.org/wiki/Lepidoptera
What is the Lepidoptera whose "boom" (population surge every 13 or 17 years) is heralded by a sudden
decrease in the local bird population about 6 months before the moth boom?
The cicada.
http://blogs.discovermagazine.com/crux/2013/06/18/the-cicada-paradox/#.Wn-iY0MtGyM
Pretty fishy that. Almost as if the cicada which has been around for like a million years or longer has figured out a way to get rid of its biggest predator before it decides to take to the air and lay lots of eggs. But how would a larva buried underground do that?
What if the cicada larva was able to create a virus capable of infecting another larva, say another super/producer with a long (though not quite 13 or 17 years long) periodicity, the Gypsy moth. What if the cicada brewed up a dose of parasitic virus that made gypsy moth larva climb to the tops of trees and wait to be eaten by birds? And what if that parasitic virus had influenza virus attached to it, ready to infect the birds? See the link below for how such a parasite works.
https://answersingenesis.org/biology/disease/parasites-affect-behavior-moths/
It would not have to be the Gypsy Moth. I mention that as just one possibility. Any worm or larva that lives in the ground side by side with the cicada would do. But Gypsy Moths are so exuberant when they decide to go "boom."
Note that scientists are currently growing influenza vaccine in the tissues of--you guessed it---armyworms.
http://www.thevaccinereaction.org/2017/10/armyworms-used-to-make-flublok-influenza-vaccine/
Coincidence? Maybe not. Here is a bit of trivia from 1939:
https://books.google.com/books?id=TjVrAAAAMAAJ&pg=PA410&lpg=PA410&dq=worms+carry+influenza&source=bl&ots=OF08BVFayo&sig=NLt3bA-oOwG0SA1G0kEhXT-VdrM&hl=en&sa=X&ved=0ahUKEwitwYea8-vYAhVBSq0KHc7KCnwQ6AEIRjAJ#v=onepage&q=worms%20carry%20influenza&f=false
A scientist studying swine flu discovered that when a pig was infected with influenza, the pig's lung worms (nematodes in this case) picked up the virus, carried it and were able to transmit it to the same or another pig if given the opportunity. Meaning that scientists have known for a long time that insects can be carriers of influenza. If a pig's lung worm can carry flu, what other worms/insects can do the same?