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Pyrethrin, a major organic chemical compound, is a broad-spectrum mosquitocide, killing both mosquitoes and their natural enemies such as dragonflies, spiders and lizards.

A lack of natural predators increases our dependence on mosquitocide, creating a vicious cycle, he said.

While Wu Mingliang encouraged the use of bio-mosquitocide which specifically targets mosquitoes and not their predators, Chen argues only a few have been developed and their effects are "undesirable."

Both Chen and Lu agreed that the fundamental measure to combat mosquitoes is to eliminate ponding, or stagnant waters where mosquitoes breed, through improved infrastructure and city planning.

Chen cited the cavernous sewers in most US cities as an example, which guarantee smooth flow of water and prevent the formation of ponds. China, however, tends to cap its narrower drainage canals with manhole and drain covers to prevent mosquitoes from laying eggs in the subterranean water collections.

Such methods are short-term solutions that fail to eliminate the root of the problem, Chen said.