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.

    70/388 page 46
    'They are elongated bodies, about a quarter of an inch long, or rather more, and resemble in shape grains of small wheat and boiled rice in colour. 106. Number of eggs and method of protection.—Each female of the migratory locust lays about eighty eggs, and they are placed in the nest or hole already described, after the pattern of the grains upon an ear of barley, or, better still, bere—(Fig. 7, page 51), glued together by a proper secretion, so as to keep them in that slanting attitude all the time. When she has deposited thus her seventy to one hundred eggs, as the case may be, she throws a white, frothy, spumous or glutinous sort of secretion—a material almost impervious to water—on the top of the eggs, to the extent of an inch or an inch and a half, until the whole is quite tapped up and on a level with the adjacent surface of the ground, as a sort of cork or stopper or protection. 107. Depth of the nest .—The depth of the nest depends some- what on the nature of the soil. There may be a certain degree of firmness or other quality required, but in any case all in that immediate vicinity have their nests about the same depth. The depth may vary somewhat according to the nature of the ground or climate, or number of eggs to be placed in the nest. 108. Gregariousness in planting nests—how to detect them.—The nests are all very close together, so that there is only a thin stratum of earth between each nest. Thus, if you dig round so as to remove a solid portion of, say, 4 in. in diameter by 5 or 6 in depth, you might have some twenty separate nests in this one piece. Each nest can easily be made out, and with care the lump of earth is such that it does not fall asunder when removed. If you remove bodily portions in the way I have described, and take the mass away from the influences of the sun, etc., progress towards fertilisation or hatching is stopped. The eggs in this case become addled, also, if the ground is harrowed or ploughed. With a little care and practice it is not difficult to detect the localities where these nests are. The evidence is that you observe this spumous material of a whitish-grey colour as you walk over the ground ; and, if in doubt, the removal of a thick layer (one-third of an inch in thickness) will manifest this still more ; or, take out one spadeful, and it will be enough to decide the point. This is an important matter, for, as wq shall afterwards see, egg-collecting is one of the most general means employed up to the present for the purpose of combating the plague. 109. A field, for chemistry.—I feel convinced that some naturalist could reap much renown by performing some well-directed experiments while the eggs are in the nests. Some conditions may be discovered in which the eggs could be rendered sterile. Life in them could be
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