Took a few clicks to track down source 10: https://history.nebraska.gov/wp-content/uploads/2017/11/doc_..., which in turn cites this book: https://www.amazon.com/Locust-Devastating-Mysterious-Disappe...

On that page you can click “read sample” and then search for “chicken” and the reference on page 3 seems to be the main source of that claim. Where that is quoting, I’m not sure.

Thanks! So the connection between the tainted taste (source on that still unknown) and this essential oil of locust is just Lockwood spitballing:

> Although the insects had no defensive chemicals in their bodies, a diet saturated with locusts rendered the eggs and flesh of chickens inedible. Studies at the time found that the locusts were remarkably rich in a “reddish-brown oil of very pungent and penetrating odor,” and perhaps this accounts for the tainted meat.

They were not "rich" in this oil:

https://archive.org/details/firstanuualrepor01unit/page/442/...

Oil, .004 percent. Still, a little oil can go a long way, so perhaps.