"A bug is going to make your summers hotter"
"An ash tree may not be a particularly memorable tree—not as iconic as a maple, not as majestic as an oak, not as whimsical as a ginkgo—but it is a good tree. A sturdy trunk stretches out into wide branches, where long clusters of oval-shaped leaves fill the canopy and provide a dappled, dignified shade.
Ashes have also become one of the most common trees along city streets and parks in many parts of North America—in Dallas, for example, ashes make up about 13 percent of all city trees and in Chicago, that number is about 17 percent. This expanse puts the trees’ canopies to good use. By providing shade and evaporating water through their leaves, they can cool down their surroundings—meaning the ash trees now dotting urban areas are a huge help when it comes to battling extreme heat.
But at the same time, ash trees are facing another ecological danger: the invasive emerald ash borer. This minuscule insect can kill an ash tree within just a few years after laying its eggs in the tree’s bark, and in some cities, they’ve already decimated much of the local ash population. According to the US Department of Agriculture, the bugs have spread to 36 states, DC, and five Canadian provinces, killing millions of ash trees as they expand their range. What researchers are starting to find out now is that the disappearance of these trees could exacerbate an already growing threat in cities and towns: increasing temperatures.
The emerald ash borer, native to eastern Asia, is quite striking. The insect, less than an inch long, wears a spectacular and shimmering pair of wings that catch the light and reflect an almost unnaturally bright green. Hidden beneath those wings is a just-as-astoundingly crimson abdomen—and if that weren’t charming enough, the ash borer’s face looks almost exactly like a classic science fiction alien, with big, black eyes taking over half its head."
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