I've had some thoughts on this that don't quite answer the question, but are offered by way of response to the question. (As my comment suggests, my hunch is that the question may be unanswerable, but I'm not in a position to know that!)
The response comes in three parts: first, some general observations about the Exodus plagues between science and biblical studies; second, a comment on the plague narratives themselves; and finally, some locust thoughts.
1. Plagues, Bible, and Science
In the intersection of interests between science and the Bible, there is a tendency for interepreters to favour the mode of explanation most familiar to them. In other words, scientists are looking for scientific explanations, and literary scholars look for literary explanations.
This has a bit of the "Doh!" about it, I know. But this tendency brings with it an opposite effect: for the scientists to read the Bible quite literally, and discount literary hypotheses, and for literary types to dismiss scientific explanations. (The dynamic is nicely exposed in this half-hour lecture.)
All of which is intended simply to inject a note of caution in this discussion and, in raising awareness of this dynamic, to hope for a rounded, balanced, and respectful engagement on the "explanations" for the Exodus plagues -- and, in fact, any number of other miraculous occurrences as recounted in the Bible.
2. The Plague traditions
The only thing I wanted to register under this heading, is that the plague narratives are, in fact, part of a literary tradition. Of course the Exodus account has pride of place, but those who investigate the development of textual traditions ("diachronically", that is, through time) see a variety of ways in which the plague traditions were remembered. Here's a small sampling:
| Exodus | Ps 78 | Ps 105 | Josephus | Philo |
| 1 | blood | blood | dark | blood | blood |
| 2 | frogs | flies | blood | frogs | frogs |
| 3 | gnats | frogs | frogs | lice | gnats |
| 4 | flies | locusts | flies | beasts | hail |
| 5 | pests | hail | gnats | disease | locusts |
| 6 | boils | pests | hail | pests | dark |
| 7 | hail | death | locusts | hail | boils |
| 8 | locusts | x | death | dark | flies |
| 9 | dark | x | x | locusts | pests |
| 10 | death | x | x | death | death |
You can see at a glance that no two of those lists are identical, but the number, order, and "content" of the plagues varies from case to case, even within biblical "accounts".
Explaining these relationships is, of course, one of the things that interpreters must do. The data itself proves nothing: it is "data"! But it does require an account that makes sense of it, and that can be done in different ways, depending on one's sensibilities and commitments. (See section 1, above!)
And finally, after the appetizers, on to the main course (as it were): locusts.
There is no archaeological evidence that will satisfy the interest and curiosity of the OP. To quote from Victor Hurowitz (see the bibliography appended below):
Admittedly, locust plagues are a universal and eternal phenomenon affecting widely scattered areas in identical manners. ... [T]he reference to the huge numbers of locusts (Joel 1:6) is quite commonplace in both biblical (Exod 10:5, 6, 15; Judg 6:5; 7:12; Jer 46:23; Nah 3:15, 17) and extrabiblical literature, especially as a number for huge numbers of destructive individiuals... (p. 601)
That isn't to say there is nothing to talk about (see the bibliography below!), but only to suggest that with the locusts -- unlike, say, an eclipse, or volcano, etc. -- we are simply faced with an absence of archaeological (or at least "external", in the case of an eclipse) evidence for the event narrated in Exodus.
What we do have is quite a lot of literary evidence. In the Bible, this is associated most often in the case of locusts with the biblical book of Joel (as a glance at the sampling of scholarly literature below will suggest).
I'll leave off my "response" here, and hope that the reflections and literature cited will be a help to those interested.
From biblical studies:
- F. S. Bodenheimer, "Note on Invasions of Palestine by Rare Locusts", Israel Exploration Journal, Vol. 1, No. 3 (1950-51), pp. 146-148.
- John Thompson, "Joel's Locusts in the Light of Near Eastern Parallels", Journal of Near Eastern Studies, Vol. 14, No. 1, Henri Frankfort Memorial Issue (Jan., 1955), pp. 52-55.
- John van Seters, "The Plagues of Egypt: Ancient Tradition or Literary Invention?", Zeitschrift für die Alttestamentliche Wissenschaft, Vol. 98 (1) (Jan 1, 1986), pp. 31-39. [van Seters is very much among those biblical scholars who believe that their reconstruction of the history of the literature renders the search for historical/archaeological evidence futile:]
The Yahwist (in the exilic period) drew upon Dtn 28, Lev 26 and the common Near Eastern curse tradition to create a series of seven plagues as the "signs and wonders" by which Yahweh delivered Israel from the Egyptians. Consequently, there was never any ancient pre-literary plague tradition. [from abstract]
- Victor Hurowitz, "Joel's Locust Plague in Light of Sargon II's Hymn to Nanaya", Journal of Biblical Literature, Vol. 112, No. 4 (Winter, 1993), pp. 597-603.
- Pablo R. Andiñach, "The Locusts in the Message of Joel", Vetus Testamentum, Vol. 42, Fasc. 4 (Oct., 1992), pp. 433-441.
- Terence E. Fretheim, "The Plagues as Ecological Signs of Historical Disaster", Journal of Biblical Literature, Vol. 110, No. 3 (Autumn, 1991), pp. 385-396.
From science and the Bible:
There is a vast amount of material here, and I'm not competent to judge what is reputable or worthwhile. Here are a couple items that address the "locust" issue:
- Mauricio Lima, "Locust plagues, climate variation, and the rhythms of nature", Proceedings of the National Academy of Science vol. 104 no. 41 (October 9, 2007), 15972–15973.
- Barbara J. Sivertsen, The Parting of the Sea: How Volcanoes, Earthquakes, and Plagues Shaped the Story of Exodus (Princeton University Press, 2009).