Mosquitoes : how they live; how they carry disease; how they are classified; how they may be destroyed / by L.O. Howard.

  • Howard, L. O. (Leland Ossian), 1857-1950.
Date:
1902
Catalogue details

Licence: In copyright

Credit: Mosquitoes : how they live; how they carry disease; how they are classified; how they may be destroyed / by L.O. Howard. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    vestigations in Africa, found that the contents of the intestines of the larvae are mainly vegetable matter—in some cases entirely so. Occasionally limbs of minute in- sects or crustaceans were found, as well as scales of mos- quitoes or other insects. On watching them feeding it is seen that all minute particles are drawn to the mouth, but many of them are rejected. This rejection is some- what arbitrary, as a particle at first rejected is often subsequently swallowed. Among the bodies seen to be swallowed I have seen living minute crustaceans and young larvae, both of Anopheles and Culices, but as a rule living animals either escape or are rejected. Chris- tophers and Stephens state that in their observations in Sierra Leone the food of the majority of the Anopheles larvae seemed to be a unicellular protococcus. Length of Life of Adult Anopheles. Physicians studying- the adults in order to determine the duration of the different stages of the malarial organ- ism have occasion to keep adult Anopheles alive in con- finement. This has been accomplished up to eight weeks by feeding them occasionally upon sliced bananas or other fruits. The adults live for very considerable spaces of time, as has, in fact, been pointed out in the first chap- ter of this book. In colder climates the adults hibernate often in houses, and in tropical climates the adults live through the dry spell to lay their eggs when the rains come and breeding-pools are re-established. The hiber- nation of Anopheles in this country has been frequently