SUNIER: Marine fish-ponds of Batavia. 263 
me Myzomyia rossi GILES | 
ILES 
Mosquito- Wz ed © .190!/,/, and Myzomyia Other 
we and Myzomyia ludlowi indlowi THEOBALD'|,°/,| Culicid 
nets THEO Lb Se 2010 ulicidae 
29 
1 1820 2461 4763 
2 256 319 655 
3 744 861 1862 
4, 2479 3318 6050 
Moraes 5299 6950 13330 
Tone es 25519 Fmosquitos! 
The open pond water therefore in this case produced 25.579 mosquitos 
per 40.000 cM?, that is about 1 mosquito for each 1'/, cM?. In the case 
of net no. 4 the production in one night even amounted to 11.842 mosquitos 
per M?, that is more than 1 mosquito per cM?. 
Consequently, as against the very slight production of mosquitos in 
open empang-water when the normal, large number of kepala timah 
are present, we have here an enormous production of mosquitos in open 
empang water whence Haplochilus panchax (HAM. BUCH.) were completely 
absent. 
Considering the fact that from the 13th to the 18th of November 
1918 the mosquito-larvae and pupae continued closely packed together all 
the time in the same strip of water along the southern margin of the long 
and narrow ponds stretching east and west, and that consequently they fed, 
grew and finally emerged in that same space, it still seems to me a moot. 
point, whether we ought to look upon the production found as the pro- 
duction of the entire pond wherein the mosquito-nets had been set or as 
the production of the southern strip alone of that pond which was occupied 
by the mosquito-larvae and -pupae. 
Also in the ponds with submerged vegetation, reaching the surface of 
the water and with overhanging marginal land-plants apart from the era- 
dication wrought among the mosquito larvae and pupae in the open water 
by the kepala timah, these larvae and pupae are not only continually driven 
together by the wind but also concentrate actively away from the open 
water into the shelter offered by the conglomerates of algae and higher 
submerged aquatic plants reaching up to just beneath the surface of the 
water and by the overhanging land-vegetation along the pond margins '). 
But even if we take the mosquitos produced by the southern strip of the pond 
without any macroscopically visible vegetation and from which kepala timah 
1) cf. note page 262. 
