_Locusts_, mainly in the abstract singular _the locust of …_, have entered figurative language via the biblical reference to the destructive swarms that consumed the crops in Egypt (the eighth of the ten plagues), and the locusts of the apocalypse. The metaphor for an overwhelming, all-devouring force is found in modern Christian-revivalist wrtiting, as in:
* _I will raise up an army of disciples and apostles in you. Ambassadors of Christ, minister’s of reconciliation. They will enter the land with a sound of preparation and restoration. They will restore the years that the locust of war have devoured. Mighty peacemakers will come from you Yugoslavia._ (link)
* _The fruit of hard parental labor was devoured by the locust of humanistic values, never to yield a truly bountiful harvest for the Lord._ (link)
From there it is only a step to a secular metaphor:
* _Pakistan was still in its first innocence, the fervour and idealism of independence lingering in the air and the locust of military rule that was to descend on the land soon – never really to leave – the last thing on anyone’s mind._ (link)
The expression _a locust of …_ also came to denote “a great number of”, maybe via the metonymy _locust»swarm_, as suggested by Nathan Bierma in his article of November 10, 2004, for the Chicago Tribune:
> Election night is when newscasters turn off their teleprompters and let their language run wild. Analyst David Gergen commented to CNN’s Lou Dobbs that Ohio and Florida were host to a “locust of lawyers” (using “locust” to mean “swarm,” because locusts swarm — columnist George Will had used the term “locust litigation”).
Other rather more obscure occurences of _a locust of …_ may be linked to this sense:
* _Is Arnold capable of leading this state, let alone this country… let alone this generation? I say no — but not because he is a Republican or that he will lead a locust of special interests into California._ (link)
* _I often day dream I have magical powers, sort of like Matilda. I would make people do funny things, start a locust of little teeny-tiny yellow fuzzy baby chicks and make a dessert buffet table appear out of nowhere._ (link)
None of these considerations explain the substitution _locus»locust_, but they provide an already rather fuzzy backdrop for it.