A monograph of the Anopheles mosquitoes of India / by S.P. James and W. Glen Liston.

  • Sydney Price James
Date:
1904
Catalogue details

Licence: In copyright

Credit: A monograph of the Anopheles mosquitoes of India / by S.P. James and W. Glen Liston. Source: Wellcome Collection.

    16/238 (page 4)
    How to distinguish Mosquitoes from other Flies adult state may, for example, be briefly described in the following way :— The adult mosquito lays its eggs on the surface of water. The eggs float on the w^ater for some days (two to four), after which time they hatch and permit of the escape of the larva. The larva is a free swimming, worm-like animal, which eats greedily and grows rapidly, casting its skin several times in the process, till it reaches its full development. At this stage it suddenly changes its form ; casting its skin, the worm-like larva assumes a comma shape, and so becomes the pupa or nympha. During the pupal period the insect ceases to eat; profound anatomical changes take place within the pupal skin, whereby the masticatory mouth parts of the larva are converted into the suctorial apparatus of the adult insect or imago. After a certain number of days the pupa-case ruptures, and the adult insect is liberated, furnished with wings and legs adapted for a life in the air. The Diptera have been divided into two great groups, termed Orthorrhapha and (iyclorrhaijha, according to the manner in which the pupa-case splits to permit of the escape of the perfect insect. In the Orthorrhapha, which includes the Culicidoe (mosquitoes), the ChironomidcB (midges), the SimulidfB (sand-flies), the Cecidomyidre. (gall-midges), the Mycetophilidce (fungus-midges), the Tipulidw (daddy-long-legs), the Tahanidce (horse-flies), etc., the pupa-case splits longitudinally down the median dorsal line. In the Cyclor- ydiapha, which includes the Syrphidcs (hoverflies), the Oestridce (bot-and warble flies), the Muscidce (house flies, tsetse flies, blue and green bottle flies, flesh flies, etc.), the perfect insect escapes by the Splitting off of a cap from the head end of the pupa. The members of some of the above families are not infrequently mistaken for mosquitoes, especially the Chirorwmidce or midges, the CecidomyidcB or gall-midges, the lipulidm, the SimulidcB, and the P^ychodidoB or owl-midges. Mosquitoes may, however, be easily distinguished from any other flies by the following characters :— (1) They possess a long sucking proboscis.* (2) The veins on their wings are covered with scales. (3) The arrangement of their wing-veins is characteristic and different from that of the members of any other family. * Except in the genera Corethra and Mochlonyx. 4]