Tehran's Answer to Whiteflies

Every summer, it's the same. Whiteflies descend upon Tehran, adding a level of nuisance to the already hot and polluted capital. 

The insects, which are related to cicadas and aphids, pose a danger to crops, and are not dangerous to human beings. But the sheer number of them is a huge irritant to city dwellers. 

Now city authorities have come up with a plan: sticky yellow traps, stuck on the barks of trees that line the city. The traps are unsightly — but they solve the problem of Tehran's annual whitefly invasion.