The locust which causes such havoc to vegetation in Africa is said to be a different species to that common to Asia, where also, though perhaps not to the same extent, it commits great ravages.
The Cape Colony has been particularly subject to this dreadful scourge, which is invariably followed by famine. The inroads of the locusts are periodical; according to Pringle, about once every fifteen years. In 1808, after having laid waste a considerable portion of the country, they disappeared, and did not return till 1824. They then remained for several years, but in 1830 took their departure. The proper home of the locust is yet a mystery. Experience only tells us that they come southward from the north. They rarely appear in any number except in years of abundance.
Almost every day during several months we encountered innumerable swarms of these insects, and it was not till we had crossed the Orange River that we fairly lost sight of them.
- Barrow, who wrote about this period, and who gives a remarkable account of the devastations of these insects, probably alludes to this very circumstance when he says,
"The present year is the third of their continuance, and their increase has far exceeded that of a geometrical progression whose ratio is a million. For ten years preceding their present visit the colony had been entirely freed from them. Their last departure was rather singular. All the full-grown insects were driven into the sea by a tempestuous northeast wind, and were afterward cast upon the beach, where, it is said, they formed a bank of three or four feet high, which extended from the mouth of the Bosjeman's River to that of the Becka, a distance of near fifty English miles; and it is asserted that when this mass became putrid, and the wind was at southeast, the stench was sensibly felt in several parts of Sneuwberg. * * * The larvæ at the same time were emigrating to the northward. The column of these imperfect insects passed the houses of two of our party, who assured me that it continued moving forward, without any interruption except by night, for more than a month."