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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    weather, as well as to some other unascertained accidental circum- stances ; but the event arrives simultaneously, not only in respect of all the eggs in that one hole or nest, but also in respect of all the others in the immediate neighbourhood, and which have been laid at the same time. The young locusts make their way to the surface at the appointed time with surprising rapidity. 113. Time occupied between nesting and birth of young.— In a very few minutes from the appearance of the first one above ground, the entire batch from the eggs in that nest are issued forth or hatched. Each nest of eggs gives out its own insects, and the whole surface of the ground seems alive with these tiny greenish-white creatures. From a few seconds to a few minutes at most after these creatures appear above ground—as soon as it can throw off its “ amniotic ” pellicle, which it sets about doing at once with alacrity—they begin to move freely about and eat. They are surprisingly active, and of course come out or are liberated with the heat of the sun. The event of incubation of the eggs is watched and looked for with more or less certainty and anxiety by the people living in the district. It is well understood to take about forty days between the nesting or depositing of the eggs and the appearance of the young. At least this is the case in the Republics bordering on the River Plate, in South America. 114. Nevertheless, one now and again comes across statements such as that it takes a year—that the flying locusts deposit the eggs this year in a certain locality and the young appear next year. On what authority this and such statements stand I know not, and from what I have seen I cannot believe it refers to the migratory locust. Others affirm that after a period of five years the young are hatched. Some say after sixteen years, and even some hold it is done after fifty years ! There is proof that in cold or very temperate regions longer time in hatching is required: eggs, e.g., are deposited in August and are only hatched in the following April. But in climates such as that in the Republics bordering on the River Plate, and generally in Africa, India, and China, the period of hatching will be found to be as stated, about forty days—from thirty to fifty. Therefore the climate, position or locality, and the nature of the soil undoubtedly exercise an influence on the length of time in regard to the process of hatching. 115. Remarkable fecundity.—As a rule all the eggs in the nest are fertile—that is to say, that when eighty eggs are laid eighty larvae come out. In a square yard of superficies the number of young hatched must be prodigious. If in 4 in. square there are, say, 20 nests, or 1600 young larvae, at the average of 80 to a nest, in a square foot there will be 90 nests, and in a square yard 800 nests. Then at the rate of 80 young ones in a nest there will be produced
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