These examples show the rewards of paying attention to both ecological and social considerations in a balanced manner when dealing with environmental problems.
Effective and enduring solutions to environmental problems cannot be expected when solutions focus only on political and economic considerations to the exclusion of ecological realities, or when they focus solely on ecological considerations to the exclusion of social realities.
The fact that this normally happens only when more water is added to a container increases the probability that a container will have enough water for the larvae to complete their development before the container dries out.
While male mosquitoes feed only on plant juices, females suck blood from animals to get the nutrients they need to develop their eggs.
The first is about eco-technology, and the second is about a regional environmental programme. Today, so many contemporary trends seem to be away from ecologically sustainable development.
How can we foster sustainable development in the face of these trends?
The case studies show how real people are responsible for innovative ideas and the entire process of transforming ideas to reality.
Sustainable development is not something that others will do for us.
Most dengue hemorrhagic fever victims are under 15 years old.
Originally a tree-hole-breeding mosquito in Africa, it long ago acquired an urban life style by breeding in similar situations around human habitations.
Aedes aegypti now breeds in man-made containers such as water storage tanks, wells, clogged rain gutters and discarded objects such as tyres, tin cans and jars that collect rainwater.
The mosquito lays her eggs on the side of a container a few millimetres above the water level.
The eggs can sit for months without hatching if they remain dry, but they hatch within minutes if covered with water.
If untreated, about 5 per cent of cases are fatal, but proper treatment can reduce fatalities to less than 1 per cent.