CORRESPONDENCE. 



A Plague for Locusts. 



In the spring of this year the coast lands of South Africa were visited by swarms 

 of locusts — fortunately a rare occurrence in these localities ; for though the 

 country further inland had often suffered from their depredations, the regions on or 

 near the coast have been mostly spared. There had not, indeed, been such a plague 

 for some thirty years. 



Mr. Maurice Evans, of Durban, an enthusiastic naturalist, heard that on a 

 certain sugar estate the locusts were dying in large numbers, and he went up to 

 investigate, and, if possible, encourage the disease. Nature seemed in this case to 

 join with man in his efforts to reduce the numbers of the invading host. "The 

 disease," he reported, " was having very marked effects. There were hundreds of 

 acres of sugar-cane with dead locusts hanging on every leaf, in one case so thickly 

 as to give a grey appearance to the otherwise green cane. They always appear, 

 when dying," he adds, " to cling tenaciously to some object, so that after death it is 

 somewhat difficult to detach them." 



Mr. Evans found that the locusts were attacked by a fungus, and he sent to the 

 British Museum several specimens preserved in spirit, that its true character might 

 be investigated. As he had surmised, the fungus proved, on examination, to be an 

 Eniomophthora, nearly allied to that which attacks house-flies. 



The first record of its appearance is in the Botanische Zeitung, 1856, p. 882. 

 Fresenius gives there an account of some grasshoppers that had been sent to him 

 which had died from the attacks of a fungus. He described it, and named it 

 Entomophthora gryllii. The disease has also been met with on locusts, and there is 

 no doubt that here, in South Africa, we are dealing with the same organism. 



The entire body-cavity of the locusts sent by Mr. Evans was filled by the coarse 

 granular mycelium of the Entomophthora — a confused tangle of rather dark- coloured 

 hyphae, with characteristic large oil-drops. Between the segments the filaments had 

 protruded and budded off spores, large pear-shaped bodies that were germinating 

 irregularly in situ, and producing again the gross-looking mycelium. Similar little 

 clumps of hyphae and spores occurred on the face of the insect. The resting-spores 

 of this species have not been recorded, and were not to be found on the specimens 

 sent by Mr. Evans. 



It is to be hoped that the disease may have effectually diminished the swarms 

 of the unwelcome visitors ; it is hardly likely that the fungus will die out. We 

 cannot say that the ranks of our house-flies have been much thinned by the ravages 

 of the constantly-recurring Empusa muscae ; but evidently the epidemic among locusts 

 is of a more virulent nature, and for the sake of agriculturists at the Cape we can 

 only wish that it may spread still further. 



Annie Lorrain Smith. 



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