Israel is not-so-eagerly awaiting a potential invasion of locusts. Swarms of the crop-devouring insects originated in northeast Africa in September, and have recently reached nearby Cyprus. Yesterday, scattered locust sightings were reported along Israel's Mediterranean coastline. Hopefully they will be controlled before they spread. (Report sightings to the Agriculture Ministry at 03-968-1500!)
Locust plagues are rare in recent decades, with the advent of international radar tracking and effective pesticides. The last plague to hit Israel was in 1959.
In normal circumstances, desert locusts live on their own like other kinds of grasshoppers. Rainy conditions encourage them to multiply, sometimes faster than the available food. When this happens, they change their behavior and start to swarm, migrating large distances in search of new food sources - which they devour in turn.
Fortunately, locusts are kosher. A swarm of locusts can destroy all vegetation across vast areas of land. Before modern food preservation techniques and large-scale food importation, virtually the only food available during a locust plague would have been locusts.
In practical terms, however, most Jewish communities outside Yemen and North Africa gave up eating locusts centuries ago. Whether they should be permitted today is a question for Israel's rabbis. I don't know whether any leading authorities have ruled on it. (Like fish, locusts are parve and need not be slaughtered before cooking.)
I also doubt I'd have the courage to sample this high-protein nosh.
In case the locusts arrive and your rabbi says yes, you might try some of these recipes. B'teyavon!