The locust plague and its suppression / by Æneas Munro.

  • Munro, Aeneas.
Date:
[1899]
Catalogue details

Licence: Public Domain Mark

Credit: The locust plague and its suppression / by Æneas Munro. Source: Wellcome Collection.

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    three, distinct species of locust-attacking fungi have been especially brought before the public in different parts of the world during the past few years. Not that they are the only ones of these plants which select the bodies of the Acridians as proper places for development, but because they, among the others, have been most persistent and active in their results. Not being a specialist in the study of insect-attacking fungi, and not having the necessary books of reference before him, the writer is unable to give a satisfactory history of these plants at this time. For the same reason, anything like a complete classification is impossible. 890. “The North American locust - killing- fungus which has been most noticeable is the one known to botanists as the Empusa grylli. It is the cause of the disease that frequently attacks and destroys myriads of both ‘ native ’ grasshoppers and the migratory ones. It works best during rather wet, warm weather in midsummer, and seems to attack the mature insects rather than the young ones. At anyrate, it is much oftener the case that the winged insects are killed by it than are the jumpers. When an insect has been once attacked by the fungus, it becomes rather sluggish in its movements, and shortly before death climbs up the stem of some weed or other plant, and securely attaches itself by tightly hugging the plant with its front and middle pairs of legs. In this position it dies, and remains clinging for some time after death. The bodies of the insects that die from the attacks of this fungus become somewhat swollen, and quite soft and brittle. A few days after death the body cracks open at the joints, thereby permitting the brown dust-like spores to escape and be blown about by the winds. Other locusts, upon eating vegetation on which such spores may be resting, if the weather and other conditions are favourable, likewise become attacked and die from the disease. It is most prevalent in the more humid parts of the United States, and also occurs to a considerable extent in the irrigated districts of the arid regions. Not unfrequently does it happen that the disease becomes so prevalent towards the close of summer that two dozen or more dead locusts may be found clinging to a single small plant. The Empusa grylli also occurs to some extent in this Republic (Argentina), where locusts killed by it have, on two or three different occasions, been found and sent to the Commission. Other quarters of the earth d are its home also. 891. The Carcarana or Argentine locust fungus.—“ Early in his investigations the writer discovered at Carcarana, in the province of Santa Fe, specimens of full-grown saltonas that had apparently died from one of the fungus diseases. A first glance at the specimens indicated that the fungus which had caused this death was quite distinct from the Empusa grylli described above. Having had some *3