Exodus 10:14

And the locust came up over all the land of Mizraim, and settled in all the limits of Mizraim exceedingly strong. Before him there had been no locust so hard, nor will there be like him.

NEITHER AFTER THEM SHALL BE SUCH [LOCUSTS]. Scripture informs us by way of prophecy that after them, there would never be such [locusts]. Now Rashi commented: “[The plague of locusts] which occurred during the days of Joel, of which it is said, There hath not been ever the like, teaches us that it was greater than that in the days of Moses. The one that happened in the days of Joel was caused by many species together: locust, caterpillar, canker-worm, palmer-worm. But the one which occurred in the days of Moses consisted only of one species, the like of which there never was and never will be.”
I have found difficulty in understanding the explanation of the Rabbi [Rashi]. It is written [of the plague which happened in the days of Moses], He also gave their produce unto the caterpillar, and it is also written, He spoke, and the locust came, and the canker-worm without number., 105:34. Thus it is clear that in the plague which occurred in the days of Moses, there were also many species of locusts involved, unlike Rashi’s explanation above. Perhaps the Rabbi [Rashi] will answer by saying that in the days of Moses, locust proper was greater than that in the days of Joel, but all other species of locusts in the days of Joel were greater than those in the days of Moses. But these are useless arguments. Instead, [we must say that the expression], in all the borders of Egypt, is connected with the end of the verse: before them there were no such locusts as they, neither after them shall be such there [in Egypt, but in other places there may be]. It is possible that because the land of Egypt is exceedingly moistened by the river, locusts are not abundant there, for these naturally come in years of drought, as is mentioned by the prophet Joel. (Joel 1:20).
Now Rabbeinu Chananel has written in his commentary on the Torah: “From the time that Moses our teacher prayed [for the removal of the locusts] till now, the locusts have not caused damage to the entire land of Egypt, and if an attack of them does occur in the Land of Israel and they proceed to enter within the border of Egypt, they do not devour the produce of the land. People say that this is known by all. Come and see! In the case of frogs, Moses said, Only in the river they will remain, and therefore the altamtzach — [the Arabic word for frogs] — have remained in the river till now. However, in the case of the locusts it is written, There remained not one locust in all the border of Egypt. It is of a phenomenon of this kind that Scripture says, Speak ye of all His marvellous works. ” Thus the language of the Rabbi.
In my opinion, the plain meaning of the verse, [neither after them shall be such], is that because the plague of locusts is known to come in all generations, and moreover since this one [in the days of Moses] came in a natural way, it having been the east wind that brought the locusts, [and there was thus reason to believe that such a plague would again come upon Egypt in a natural way], Scripture therefore states that such locusts were the greatest that ever occurred in the natural order of things. Neither before them were there such locusts as they, nor after them shall be such. Through the magnitude of the plague, the Egyptians thus knew that it was a special act of G-d, since the like never happened before. [The plague] that occurred in the days of Joel was likewise a special act of G-d, [and hence Scripture also describes it by saying, There hath never been the like].

ואחריו, “and after it (there will never again be a plague of locust of such dimensions.)”. When describing a similar plague in the Book of Yoel,2,2, the prophet stated s that never again had there been a plague of locusts of such dimensions, nor would there ever be again. Apparently there are many different strains of locusts, and the statements by both the Torah and the Book of Yoel do not refer to the same strain. Even so, we are puzzled by a statement in Psalms 78,46, as well as 105,34-35 as the same strains of locusts are mentioned. Possibly, in the days of Moses all the different strains of locusts combined to invade that country at the same time. [A week before writing these lines, the land of Israel was invaded by a plague of locusts originating in Egypt and was repelled by spraying poison from airplanes. Our farmers had been very concerned. Ed.] The references in Yoel apparently must have referred to one specific strain that invaded the land of Israel at that time in such intensity. The Torah treated the strain known as ארבה and that of ילק as distinct species. [This makes sense as some kinds of “locusts,” are permitted to us as food, whereas other kinds are not. Ed.]