060 DOMESTIC ANIMALS, DAIRYING, ETC. 



While Stegomyia Scutellaris breeds in such places as mentioned in 

 connection with the yellow-fever species, it differs from the latter 

 in that it is not restricted to such collections of water. It has often 

 been found breeding in small bodies of water in the forest. These 

 places have been sometimes far removed from habitations and on 

 several occasions have been discovered where not more than one 

 person would visit, on the average, in a year's time. These natural 

 breeding places are such small amounts of water as may be con- 

 tained in a hollow stump of a tree or limb, a depression in a stone 

 in the bed of a mountain stream, or the leaves of plants. 



Natural Enemies and Diseases of Mosquitoes. The dragon- 

 flies or mosquito-hawks are the most effectual enemies of the mos- 

 quitoes that we have here. The dragon-flies, Odenata, are for the 

 most part members of the single genus Agrion. In searching the 

 swampy places for the larvae of the mosquito it was not unusual 

 to dip up with the same dipperful of water from the net, the larvae 

 of mosquitoes and the nymphs or young of dragon-flies, while the 

 adult dragon-flies could be seen flying in myriads over these places. 

 This is significant when it is known that the dragon-fly is preda- 

 ceous in both the young and the adult forms ; the young dragon-fly, 

 an aquatic insect, feeding on the larvae of the mosquito in the water 

 and the adult preying on the winged insect in the air. This highly 

 beneficial, strong flying and beautiful insect is met at all elevations. 



A single gold-fish in an aquarium ate over one hundred and 

 fifty larvas in twenty-four hours' time. Other specimens placed in 

 pools containing mosquito larvae were afterwards dissected and the 

 stomach contents were found to consist almost entirely of the re- 

 mains of the bodies of larvae. From these experiments, gold-fish 

 were placed in watering-troughs, tanks and pools, with the result 

 that the young of mosquitoes did not develop in these places. 

 Search was made for larvae in lily-ponds and fountains where gold- 

 fish occurred and conditions verified the above experiments. 

 (Hawaii E. S. B. 6.) 



Abolition of Breeding Places. In considering this general 

 question just as in considering so many questions relating to mos- 

 quitoes, a complication arises from the enormous mass of facts 

 concerning the life histories of the different species of mosquitoes; 

 facts discovered, for the most part, in the past three or four years. 

 There is much diversity in the breeding places of different species. 

 Those of the two commonest household mosquitoes, namely, Culex 

 pipiens in the North and C. quinquefasciatus and Aedes (Stegom- 

 yia) calopus in the South, correspond well to generalizations for- 

 merly named, breeding as these specias do in every chance recep- 

 tacle of water about residences, and their destruction means the 

 abolition of all such receptacles. Where the rain-water barrel or 

 the rain-water tank are necessary they should be screened. In New 

 Orleans and other southern cities the boards of health are now 

 enforcing such screening. This should be done with extreme care, 

 a fine mesh wire being used and the fitting being made very perfect. 



