Business Premises And Industrial Areas.

Many of the commercial houses in Auckland have drains round the sides and backs of buildings to carry rain water to the gully-traps. Frequently these were found to be blocked by a small quantity of earth or debris and enormous numbers of mosquitoes were breeding in the small pool thus formed. One drain, 9 inches across, 3 inches deep, and 50 feet long was found to contain 200,000 mosquito larvae and pupae; a couple of broom-sweeps would have removed the small obstruction and swept away the developing mosquitoes.

All too frequently, tins and other containers, old tyres and similar rubbish are thrown out into the warehouse yard and left “until there is enough for a load.” Meanwhile thousands of mosquitoes are bred out.

In industrial yards, private, municipal and government, there are usually lumbers of casks, barrels, oil drums and bitumen tins which hold rain water and form ideal breeding places for C pervigilans. (Pl. 19, fig. 2.)

Garages, construction shops and railway yards all have a litter of old cars or their parts, engine cabs and trucks (pl. 19, fig. 3); boat-building yards have oil and paint tins lying about and old boats and launches. All these can hold enough water for breeding innumerable mosquitoes.