PECULIAR HABITATS 149 



In the moist tropics the -water-filled ends of broken bamboos furnish breeding- 

 places to a number of species. In America among the bamboo inhabitants the 

 sabethids again rank first in number of species belonging to several genera ; 

 of culicines there are representatives of Culcx, Carrollia, Stegoconops and 

 Megarliinus. Here again we have, among these species restricted to a peculiar 

 habitat, predaceous forms (Sahethinus, Megarliinus) which prey upon the 

 others. A few species of Sabethini breed in the wat«r of cocoanut and cacao- 

 husks and their larvge are rarely found elsewhere. The larvae of Limatus and 

 of Johlotia digitaius are constantly found in these husks and they thrive there 

 no matter how foul the liquid, as a result of the decomposing vegetable matter, 

 may become. 



A peculiar habitat is furnished by certain reeds growing in swamps. The 

 leaves begin to spread below the surface of the water and thus form a chamber 

 isolated from the surrounding water. The larvae of several species of Wyeomyia 

 have been found in this situation and Lutz has found there the larva of 

 Menolepis. 



In the tide-water regions of the American tropics certain crabs live in holes 

 in the soil which go below the water level. In the water in these holes, some- 

 times at a considerable depth below ground, certain species of mosquitoes breed. 

 Most remarkable of these are the specialized forms of Deinocerites and related 

 genera. Besides these there are a number of species of Culex peculiar to the 

 crab-holes and even structurally these show more or less adaptation to their 

 habitat. 



The most peculiar and specialized larvae of mosquitoes yet discovered are the 

 species of Mansoniu {Tceniorhynchus, auct.). The habits of these larvae have 

 recently been worked out with our common Mansonia perturhans and the same 

 habits are indicated for Mansonia fasciolatus and M. arrihalzagce. The eggs are 

 laid in swamps where there is a dense growth of grass and sedges. The newly 

 hatched larvae make their way down through the water to the roots of these 

 plants and there they attach themselves by inserting the apex of the peculiarly 

 constructed breathing- tube. Here they remain anchored until full grown, ob- 

 taining air through the vascular tissues of the plant-roots. The pupa, it appears, 

 remains in the same situation, deriving air from the roots by means of its 

 peculiarly modified thoracic " breathing trumpets." The habits of Mansonia 

 titillans are similar according to the observations of H. W. B. Moore, except that 

 the host plant is Pistia, an aquatic plant belonging to the Araceae, which grows 

 in floating tufts, the roots loosely entangled in the mud. 



The subject of the character of water frequented by the larvae of different 

 species has already been touched upon in the discussion of their habitats. By 

 far the largest number of species frequent fresh water. Certain species, how- 

 ever, occur in saline water and some in water charged with alkali. Some species 

 thrive in sea-water of full strength and even in water, as a result of evaporation, 

 of much greater salinity. The larvae of these same species will do equally well 

 in brackish or even in entirely fresh water. This is important in the economy 

 of the species as opportunities for larval development may be produced at one 



