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.
> 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.